Shahid Beheshti UniversityResearches in Earth Sciences2008-829916220250522Ore mineralogy, mineral chemistry and genesis of carbonate-hosted
zinc-lead non-sulfide deposit, Mansourabad, central IranOre mineralogy, mineral chemistry and genesis of carbonate-hosted
zinc-lead non-sulfide deposit, Mansourabad, central Iran11810582610.48308/esrj.2025.238998.1263FAShirinKhadivarDepartment of Geology, Faculty of Earth Sciences, Shiraz University, Shiraz, Iran0000-0001-8948-8150BatoulTaghipourDepartment of Geology, Faculty of Earth Sciences, Shiraz University, Shiraz, IranJournal Article20250302<strong>Introduction</strong><br />Iran possesses vast regions with high potential for carbonate-hosted Zn–Pb deposits, largely due to its favorable geodynamic framework (Rajabi et al, 2012). The majority of the country’s sedimentary-hosted lead and zinc deposits are concentrated within four major metallogenic belts, spanning from the Early Cambrian to the Tertiary period and occurring in a diverse range of siliciclastic and carbonate rock formations. These belts include Central Alborz, Tabas-Posht-e-Badam, Malayer-Esfahan, and Yazd-Anarak (Fazli et al, 2019; Rajabi et al, 2012, 2023). Among these, the Yazd-Anarak Metallogenic Belt (YAMB), located within the Yazd Block in western Central Iran, hosts some of the country’s largest lead and zinc deposits, including Mehdiabad, Darreh Zanjir, and Mansourabad. This region is recognized as one of Iran’s most significant metallogenic provinces. The Mansourabad deposit, situated approximately 75 km southwest of Yazd city, lies within the Yazd-Anarak metallogenic belt and represents a key Pb-Zn mineralization site. Despite the previous geological, mineralogical, geochemical studies the Mansourabad sulfide ore, there are no detailed investigations on the Mansourabad non-sulfide ore. The main objective of this study is to comprehensively investigate the mineralogical, textural, and petrographic characteristics of the Mansourabad non-sulfide ores and to develop a genetic model.<br /><strong> </strong><br /><strong>Materials and Methods</strong><br /><strong>Sampling and analytical methods</strong><br />For geological investigations and the study of non-sulfide ore characteristics (identification of zinc-bearing minerals using Zinc Zap fluid), field visits were conducted, and 30 samples were collected from all sections. To carry out mineralogical studies and examine the structure and texture of the non-sulfide ore, 15 XRD analyses, 12 thin sections, and 15 polished thin sections were prepared at ZarAzma Laboratory and studied at Shiraz University. All thin sections and polished thin sections were examined using an Olympus microscope under both XPL and PPL light at magnifications of 4X and 10X. Additionally, to identify mineral phases and analyze the distribution and concentration of elements, 12 polished thin sections were studied using a scanning electron microscope (SEM) model TESCAN-Vega3, which has a resolution higher than 50 nanometers, at the Central Laboratory of Shiraz University. Before conducting the study of polished thin sections in this device, all sections had to be coated with gold using a sputter coater.<br /><strong>Geologic setting and Ore Mineralogy </strong><br />Mansourabad deposit is hosted by the Lower Cretaceous sedimentary sequence in the south of the Yazd basin. This sequence is based on lithological differences characteristics from bottom to top classified into three parts: Sangestan Formation, Taft Formation, and Abkoh Formation.<br /><br /><br /><br /><br />Ore mineralogy, mineral chemistry and genesis of carbonate-hosted zinc-lead non-sulfide deposit Khadivar and Taghipour / 2<br /><br /><br /><br /><br />Sulfide and non-Sulfide Zn-Pb mineralization is formed in the upper part of the dolomites of the Taft formation. The mineral observed in the sulfide part is generally galena, Sphalerite is rarely occurred due to it leached into non-sulfide zinc minerals. The field observations, petrographic and XRD results, determined that the main minerals of the non-sulfide ore included smithsonite, hydrozincite, hemimorphite and cerussite along with iron oxides.<br /><strong> </strong><br /><strong>Results and Discussion</strong><br />Dolomitization is the major hydrothermal alteration styles in the Mansourabad deposit. According to the textural and petrographical studies, three types of dolomites were identified in Mansourabad Zn-Pb deposit Among these, type III dolomite (hydrothermal dolomite) hosts sulfide and non-sulfide mineralization in this deposit. Seawater is the source of fluids in this deposit, which, by circulating in the detrital sedimentary rocks of the underlying unit (Sangestan Formation), leach metals such as lead, zinc, silver, and copper (metal-bearing brine), moves upward through the syn-sedimentary normal fault. Mixing of acidic metal-bearing brine with cold, reduce, sulfur-containing seawater causes the formation of hydrothermal dolomite and the deposition of sulfide mineralization sub-seafloor in the limestone unit (hydrothermal dolomite) of the Taft Formation. Like all non-sulfide deposits in the world, the Mansourabad non-sulfide ore was formed under conditions of uplift, dry climate, and fault development. In the Late Cretaceous, the closing of the Neotethys ocean and the dominance of pressure conditions in central Iran led to the creation of orogenic activities (the formation of the Laramide orogeny) and a structure that, together with the climatic conditions (hot and dry) of Central Iran, caused the weathering and oxidation of the sulfide part and its transformation and change into the non-sulfide part. Faults in the Mansourabad deposit have led to the penetration of oxidizing meteoric waters into the host rock (carbonate rocks) and their dissolution. This interaction between oxide fluids and sulfide ore has caused the formation of the non-sulfide part in the Mansourabad deposit in the form of host rock replacement (white ore), sulfide mineral replacement (red ore). In dry climates, dissolved oxygen in meteoric waters reaches its highest level compared to other climates.<br /><strong> </strong><br /><strong>Conclusion</strong><br />The Mansourabad non-sulfide ore deposit is hosted within the dolomitized limestones of the Taft Formation, dating back to the Early Cretaceous. This deposit contains both sulfide and non-sulfide mineralization. In the non-sulfide zone, minerals such as smithsonite, hydrozincite, hemimorphite, and cerussite, along with iron oxides, are observed. The most significant type of alteration in this area is dolomitization, followed by calcitization. The formation of the non-sulfide ore in this region has been influenced by various factors, including the composition of primary minerals (which determines the type of secondary minerals), the nature of the host rocks, faults and fractures (which facilitate water infiltration and accelerate oxidation), and climatic conditions. In the Late Cretaceous, with the closure of the Neotethys Ocean and the Laramide orogeny, tectonic pressures, along with the warm and arid conditions of Central Iran, intensified the weathering and oxidation of sulfides. The rapid uplift of the crust brought sulfide minerals closer to the surface, accelerating their oxidation. Additionally, faults provided pathways for oxidizing meteoric waters, facilitating the dissolution of the host rock and the replacement of sulfide minerals. These conditions led to the extensive oxidation of sulfides and the formation of the non-sulfide ore deposit in the region.<strong>Introduction</strong><br />Iran possesses vast regions with high potential for carbonate-hosted Zn–Pb deposits, largely due to its favorable geodynamic framework (Rajabi et al, 2012). The majority of the country’s sedimentary-hosted lead and zinc deposits are concentrated within four major metallogenic belts, spanning from the Early Cambrian to the Tertiary period and occurring in a diverse range of siliciclastic and carbonate rock formations. These belts include Central Alborz, Tabas-Posht-e-Badam, Malayer-Esfahan, and Yazd-Anarak (Fazli et al, 2019; Rajabi et al, 2012, 2023). Among these, the Yazd-Anarak Metallogenic Belt (YAMB), located within the Yazd Block in western Central Iran, hosts some of the country’s largest lead and zinc deposits, including Mehdiabad, Darreh Zanjir, and Mansourabad. This region is recognized as one of Iran’s most significant metallogenic provinces. The Mansourabad deposit, situated approximately 75 km southwest of Yazd city, lies within the Yazd-Anarak metallogenic belt and represents a key Pb-Zn mineralization site. Despite the previous geological, mineralogical, geochemical studies the Mansourabad sulfide ore, there are no detailed investigations on the Mansourabad non-sulfide ore. The main objective of this study is to comprehensively investigate the mineralogical, textural, and petrographic characteristics of the Mansourabad non-sulfide ores and to develop a genetic model.<br /><strong> </strong><br /><strong>Materials and Methods</strong><br /><strong>Sampling and analytical methods</strong><br />For geological investigations and the study of non-sulfide ore characteristics (identification of zinc-bearing minerals using Zinc Zap fluid), field visits were conducted, and 30 samples were collected from all sections. To carry out mineralogical studies and examine the structure and texture of the non-sulfide ore, 15 XRD analyses, 12 thin sections, and 15 polished thin sections were prepared at ZarAzma Laboratory and studied at Shiraz University. All thin sections and polished thin sections were examined using an Olympus microscope under both XPL and PPL light at magnifications of 4X and 10X. Additionally, to identify mineral phases and analyze the distribution and concentration of elements, 12 polished thin sections were studied using a scanning electron microscope (SEM) model TESCAN-Vega3, which has a resolution higher than 50 nanometers, at the Central Laboratory of Shiraz University. Before conducting the study of polished thin sections in this device, all sections had to be coated with gold using a sputter coater.<br /><strong>Geologic setting and Ore Mineralogy </strong><br />Mansourabad deposit is hosted by the Lower Cretaceous sedimentary sequence in the south of the Yazd basin. This sequence is based on lithological differences characteristics from bottom to top classified into three parts: Sangestan Formation, Taft Formation, and Abkoh Formation.<br /><br /><br /><br /><br />Ore mineralogy, mineral chemistry and genesis of carbonate-hosted zinc-lead non-sulfide deposit Khadivar and Taghipour / 2<br /><br /><br /><br /><br />Sulfide and non-Sulfide Zn-Pb mineralization is formed in the upper part of the dolomites of the Taft formation. The mineral observed in the sulfide part is generally galena, Sphalerite is rarely occurred due to it leached into non-sulfide zinc minerals. The field observations, petrographic and XRD results, determined that the main minerals of the non-sulfide ore included smithsonite, hydrozincite, hemimorphite and cerussite along with iron oxides.<br /><strong> </strong><br /><strong>Results and Discussion</strong><br />Dolomitization is the major hydrothermal alteration styles in the Mansourabad deposit. According to the textural and petrographical studies, three types of dolomites were identified in Mansourabad Zn-Pb deposit Among these, type III dolomite (hydrothermal dolomite) hosts sulfide and non-sulfide mineralization in this deposit. Seawater is the source of fluids in this deposit, which, by circulating in the detrital sedimentary rocks of the underlying unit (Sangestan Formation), leach metals such as lead, zinc, silver, and copper (metal-bearing brine), moves upward through the syn-sedimentary normal fault. Mixing of acidic metal-bearing brine with cold, reduce, sulfur-containing seawater causes the formation of hydrothermal dolomite and the deposition of sulfide mineralization sub-seafloor in the limestone unit (hydrothermal dolomite) of the Taft Formation. Like all non-sulfide deposits in the world, the Mansourabad non-sulfide ore was formed under conditions of uplift, dry climate, and fault development. In the Late Cretaceous, the closing of the Neotethys ocean and the dominance of pressure conditions in central Iran led to the creation of orogenic activities (the formation of the Laramide orogeny) and a structure that, together with the climatic conditions (hot and dry) of Central Iran, caused the weathering and oxidation of the sulfide part and its transformation and change into the non-sulfide part. Faults in the Mansourabad deposit have led to the penetration of oxidizing meteoric waters into the host rock (carbonate rocks) and their dissolution. This interaction between oxide fluids and sulfide ore has caused the formation of the non-sulfide part in the Mansourabad deposit in the form of host rock replacement (white ore), sulfide mineral replacement (red ore). In dry climates, dissolved oxygen in meteoric waters reaches its highest level compared to other climates.<br /><strong> </strong><br /><strong>Conclusion</strong><br />The Mansourabad non-sulfide ore deposit is hosted within the dolomitized limestones of the Taft Formation, dating back to the Early Cretaceous. This deposit contains both sulfide and non-sulfide mineralization. In the non-sulfide zone, minerals such as smithsonite, hydrozincite, hemimorphite, and cerussite, along with iron oxides, are observed. The most significant type of alteration in this area is dolomitization, followed by calcitization. The formation of the non-sulfide ore in this region has been influenced by various factors, including the composition of primary minerals (which determines the type of secondary minerals), the nature of the host rocks, faults and fractures (which facilitate water infiltration and accelerate oxidation), and climatic conditions. In the Late Cretaceous, with the closure of the Neotethys Ocean and the Laramide orogeny, tectonic pressures, along with the warm and arid conditions of Central Iran, intensified the weathering and oxidation of sulfides. The rapid uplift of the crust brought sulfide minerals closer to the surface, accelerating their oxidation. Additionally, faults provided pathways for oxidizing meteoric waters, facilitating the dissolution of the host rock and the replacement of sulfide minerals. These conditions led to the extensive oxidation of sulfides and the formation of the non-sulfide ore deposit in the region.https://esrj.sbu.ac.ir/article_105826_7887df8a0b17cb48be48f71e8987b624.pdfShahid Beheshti UniversityResearches in Earth Sciences2008-829916220250522Application of fold style elements for estimation of strain parameters
(Case study: Asmari horizon of Karanj oil field)Application of fold style elements for estimation of strain parameters
(Case study: Asmari horizon of Karanj oil field)193510582310.48308/esrj.2025.237325.1238FABabakSamaniDepartment of Geology, Faculty of Earth Sciences, Shahid Chamran University of Ahvaz, Ahvaz, IranAfshinCheraghiDepartment of Geology, Faculty of Earth Sciences, Shahid Chamran University of Ahvaz, Ahvaz, IranAbbasCharchiDepartment of Geology, Faculty of Earth Sciences, Shahid Chamran University of Ahvaz, Ahvaz, IranJournal Article20241028<strong>Introduction</strong>
Strain analysis in natural deformed rocks is very important for understanding the strain states in different parts of the earth's crust. Using data that can be collected in the field, and applying different methods in strain studies, geologists will be able to measure quantitative amounts of strain in various geological structures. Since geologists are always dealing with the latest deformed products in the earth's crust, they will be able to perform finite strain analysis in structural features or deformed rocks (Ramsay and Hubber, 1983). If geologists need to investigate the changes of incremental strain values at any moment of time in different parts of a structure, the use of laboratory and numerical modeling will be inevitable. In carrying out numerical analysis of strain, it is very important to find elements that can be used as indicators in strain measurement. Several methods have been presented by different researchers to estimate strain values in metamorphic rocks. Methods such as Rf/Φ method (Ramsay and Hubber, 1983), Fry method (Fry, 1979), Bridin method, Wellman method, and the method of preparing balanced cross sections (Ferhner and Grasemann, 2012; Lopez-Mir, 2019) are the most common methods of strain studies, which are used by Structural geologist in different natural deformed areas. Usually, two-dimensional strain studies can help to understand the characteristics of strain ellipsoid in three dimensions. There are several mathematical methods that help to structural geologist for understand the 3D nature of strain from 2D studies. Using of graphical functions is very common in many strain studies. In recent decades, the use of graphical functions (Nomograms) as a quick and simple method in strain analysis is used by many researchers (Ramsay and Hubber, 1983; Imber et al, 2012; Fossen, 2016; Sarkarinrjad et al, 2017, Keshavarz and Faghih, 2020). In this research, the amounts of strain ratio and shortening value in deferent parts of Karanj anticline oil field have been calculated with application of seismic profiles and using fold style elements.
<strong> </strong>
<strong>Materials and Methods</strong>
In this research, using interpreted seismic sections, some parameters of the fold style elements in the Karanj anticline oil field have been investigated. Interlimb angle, folding angle, geometry of the axial surface, bluntness and fold aspect ratio were determined. Also the Ramsay and Fourier classification were made for deferent part of anticline. By applying the interlimb angle value and by using graphical functions, the fold aspect ratio of Karanj anticline was calculated in different parts. Also, using the fold aspect ratio-shortening and shortening-strain ratio nomograms, the values of shortening and strain ratio were estimated for different parts of anticline.
Application of fold style elements for estimation of strain parameters Samani et al, / 20
<strong>Results and Discussion</strong>
The analyzes based on the value of the curvature of the folded surfaces between the hinge and inflection points of the fold show that the Karanj anticline is located in the range of sinusoidal to parabolic folds based on the Fourier division and according to the almost equal curvature of the folded surfaces and uniformity The real thickness of the folded layer is placed in the class 1B group of folds. The fold bluntness parameter is measured based on the ratio of the radius of curvature at the fold closure to the radius of curvature tangent to the edges of the fold at the inflection points of the fold. According to the results, the Karanj anticline with the value of b=0.22 to b=0.64 is sub-angular to sub-rounded folds. The measurement of the interlimb angle in different parts of the Asmara horizon shows a gentle to open fold. Using the interlimb angle values and application of interlimb angle-fold aspect ratio nomogram, the values of the fold aspect ratio of the Karanj anticline were determined in the range of 0.15 to 0.44. Based on this amounts, the general geometry of the Karanj anticline is placed in the group of broad to wide folds. In order to determine the amount of shortening and the strain ratio in Asmari folded layer, various mathematical relationships and graphical functions have been presented (Ramsay and Hubber, 1983; Bastida et al., 2005, 2007; Ghassemi et al., 2010). It is possible to measure the shortening values by using the fold aspect ratio and using equation 1.
Eq. 1)
P = 0.5(1/(1+e)<sup>2</sup>-1)<sup>0.5</sup>
Also, by using shear strain and determining the values of the square of elongation (Equation, 2), it is possible to determine the values of the strain ratio (Equation, 3).
Eq. 2)
λ1 or λ3 = 1/2 (γ<sup>2</sup>+2±γ(γ<sup>2</sup>+4)<sup>1/2</sup>)
Eq 3)
R<sup>2</sup>= λ1/ λ3
In order to determine the values of the strain ratio using equation 4, it is also possible to use the values of the fold aspect ratios (Ghassemi et al, 2010).
Eq 4)
P= 0.5(R-1)<sup>0.5</sup> or R= 4P<sup>2</sup>+1
Also, by using the equation 5, it is possible to establish a relationship between the shortening values and the strain ratio.
Eq 5)
e = (1/R<sup>0.5</sup>)-1
In this research, using graphical functions, the values of shortening and strain ratio were determined along the seismic profiles in different parts of the Asmari horizon for the Karanj anticline. The results of this research show that the Karanj oil field anticline is an asymmetric fold with different amounts of interlimb angel along the anticline. Based on the analysis, the values of interlimb angle are not the same throughout the Karanj anticline and it shows lower values in the central parts than in the northern and southern parts of the anticline. Based on the amounts of interlimb angles in different parts, the Karanj anticline is mainly can be categorized in the gentle to open folds. Based on the amounts of bluntness the Karanj anticline is placed in the sub-angular to sub-rounded folds. According to the dip isogon patterns (Ramzay method) and Fourier analysis the Karanj anticline is categorized in the 1B and Sinusoidal to parabolic folds. Based on the strain analyses the values of the strain ratio and shortening percentage in the central parts of the anticline show higher values than the northern and southern parts.
<strong> </strong>
<strong>Conclusion</strong>
Based on the fold style elements and strain analyses of the Karanj anticline oil field, the following results were obtained:
- The interlimb angles along the Karanj anticline are varying between 74 to 140 degrees.
- The bluntness values of the Karanj anticline oil field is 0.22<b<0.64 and shows the geometry of sub-angular to sub-rounded fold.
- The fold aspect ratio for the Karanj anticline is between (0.15 to 0.44) and based on these amounts shows the geometry of broad to wide folds.
- Also, the results show the shortening values between 7.5% to 32% and strain ratio values in the range of 1.25 to 1.45 in different parts of the anticline.<strong>Introduction</strong>
Strain analysis in natural deformed rocks is very important for understanding the strain states in different parts of the earth's crust. Using data that can be collected in the field, and applying different methods in strain studies, geologists will be able to measure quantitative amounts of strain in various geological structures. Since geologists are always dealing with the latest deformed products in the earth's crust, they will be able to perform finite strain analysis in structural features or deformed rocks (Ramsay and Hubber, 1983). If geologists need to investigate the changes of incremental strain values at any moment of time in different parts of a structure, the use of laboratory and numerical modeling will be inevitable. In carrying out numerical analysis of strain, it is very important to find elements that can be used as indicators in strain measurement. Several methods have been presented by different researchers to estimate strain values in metamorphic rocks. Methods such as Rf/Φ method (Ramsay and Hubber, 1983), Fry method (Fry, 1979), Bridin method, Wellman method, and the method of preparing balanced cross sections (Ferhner and Grasemann, 2012; Lopez-Mir, 2019) are the most common methods of strain studies, which are used by Structural geologist in different natural deformed areas. Usually, two-dimensional strain studies can help to understand the characteristics of strain ellipsoid in three dimensions. There are several mathematical methods that help to structural geologist for understand the 3D nature of strain from 2D studies. Using of graphical functions is very common in many strain studies. In recent decades, the use of graphical functions (Nomograms) as a quick and simple method in strain analysis is used by many researchers (Ramsay and Hubber, 1983; Imber et al, 2012; Fossen, 2016; Sarkarinrjad et al, 2017, Keshavarz and Faghih, 2020). In this research, the amounts of strain ratio and shortening value in deferent parts of Karanj anticline oil field have been calculated with application of seismic profiles and using fold style elements.
<strong> </strong>
<strong>Materials and Methods</strong>
In this research, using interpreted seismic sections, some parameters of the fold style elements in the Karanj anticline oil field have been investigated. Interlimb angle, folding angle, geometry of the axial surface, bluntness and fold aspect ratio were determined. Also the Ramsay and Fourier classification were made for deferent part of anticline. By applying the interlimb angle value and by using graphical functions, the fold aspect ratio of Karanj anticline was calculated in different parts. Also, using the fold aspect ratio-shortening and shortening-strain ratio nomograms, the values of shortening and strain ratio were estimated for different parts of anticline.
Application of fold style elements for estimation of strain parameters Samani et al, / 20
<strong>Results and Discussion</strong>
The analyzes based on the value of the curvature of the folded surfaces between the hinge and inflection points of the fold show that the Karanj anticline is located in the range of sinusoidal to parabolic folds based on the Fourier division and according to the almost equal curvature of the folded surfaces and uniformity The real thickness of the folded layer is placed in the class 1B group of folds. The fold bluntness parameter is measured based on the ratio of the radius of curvature at the fold closure to the radius of curvature tangent to the edges of the fold at the inflection points of the fold. According to the results, the Karanj anticline with the value of b=0.22 to b=0.64 is sub-angular to sub-rounded folds. The measurement of the interlimb angle in different parts of the Asmara horizon shows a gentle to open fold. Using the interlimb angle values and application of interlimb angle-fold aspect ratio nomogram, the values of the fold aspect ratio of the Karanj anticline were determined in the range of 0.15 to 0.44. Based on this amounts, the general geometry of the Karanj anticline is placed in the group of broad to wide folds. In order to determine the amount of shortening and the strain ratio in Asmari folded layer, various mathematical relationships and graphical functions have been presented (Ramsay and Hubber, 1983; Bastida et al., 2005, 2007; Ghassemi et al., 2010). It is possible to measure the shortening values by using the fold aspect ratio and using equation 1.
Eq. 1)
P = 0.5(1/(1+e)<sup>2</sup>-1)<sup>0.5</sup>
Also, by using shear strain and determining the values of the square of elongation (Equation, 2), it is possible to determine the values of the strain ratio (Equation, 3).
Eq. 2)
λ1 or λ3 = 1/2 (γ<sup>2</sup>+2±γ(γ<sup>2</sup>+4)<sup>1/2</sup>)
Eq 3)
R<sup>2</sup>= λ1/ λ3
In order to determine the values of the strain ratio using equation 4, it is also possible to use the values of the fold aspect ratios (Ghassemi et al, 2010).
Eq 4)
P= 0.5(R-1)<sup>0.5</sup> or R= 4P<sup>2</sup>+1
Also, by using the equation 5, it is possible to establish a relationship between the shortening values and the strain ratio.
Eq 5)
e = (1/R<sup>0.5</sup>)-1
In this research, using graphical functions, the values of shortening and strain ratio were determined along the seismic profiles in different parts of the Asmari horizon for the Karanj anticline. The results of this research show that the Karanj oil field anticline is an asymmetric fold with different amounts of interlimb angel along the anticline. Based on the analysis, the values of interlimb angle are not the same throughout the Karanj anticline and it shows lower values in the central parts than in the northern and southern parts of the anticline. Based on the amounts of interlimb angles in different parts, the Karanj anticline is mainly can be categorized in the gentle to open folds. Based on the amounts of bluntness the Karanj anticline is placed in the sub-angular to sub-rounded folds. According to the dip isogon patterns (Ramzay method) and Fourier analysis the Karanj anticline is categorized in the 1B and Sinusoidal to parabolic folds. Based on the strain analyses the values of the strain ratio and shortening percentage in the central parts of the anticline show higher values than the northern and southern parts.
<strong> </strong>
<strong>Conclusion</strong>
Based on the fold style elements and strain analyses of the Karanj anticline oil field, the following results were obtained:
- The interlimb angles along the Karanj anticline are varying between 74 to 140 degrees.
- The bluntness values of the Karanj anticline oil field is 0.22<b<0.64 and shows the geometry of sub-angular to sub-rounded fold.
- The fold aspect ratio for the Karanj anticline is between (0.15 to 0.44) and based on these amounts shows the geometry of broad to wide folds.
- Also, the results show the shortening values between 7.5% to 32% and strain ratio values in the range of 1.25 to 1.45 in different parts of the anticline.https://esrj.sbu.ac.ir/article_105823_763a42da6c38cd64adb4ffcbebfa4292.pdfShahid Beheshti UniversityResearches in Earth Sciences2008-829916220250522Biostratigraphy of upper Triassic deposits in Cheshmeh Gaz section (Southern parts of the Posht Badam Block), Central IranBiostratigraphy of upper Triassic deposits in Cheshmeh Gaz section (Southern parts of the Posht Badam Block), Central Iran365210583110.48308/esrj.2025.105831FANooshinHadadiDepartment of Geology, Faculty of Basic Sciences, Shiraz Branch, Islamic Azad University, Shiraz, Iran0000-0002-5625-3280MassihAfghahDepartment of Geology, Faculty of Basic Sciences, Shiraz Branch, Islamic Azad University, Shiraz, Iran0000-0001-8155-087XJournal Article20241010<strong>Introduction</strong>
As the oldest member of the Shemshak group, the Nayband formation has been widely outcropped in Central Iran. It has been important to geologists for a long time due to its significant coal deposits. Accordingly, the geological data about the Nayband Formation is relatively extent that geological studies have been carried out on almost all known outcrops of this formation. Considering that the deposits belonging to the Upper Triassic in the subcontinental blocks of Central Iran are different according to the performance of the previous Cimmerian event due to having separate characteristics, and due to the heterogeneous activities of the blocks of Central Iran, the mentioned deposits have various depositional environments (Seyed-Emami et al, 2004). Nayband Formation is sandwiched between carbonate sediment of Shotori Formation (below) and clastic sediment of Ab Haji Formation. Actually, the underalid formation (dolomite of Shotori Formation) is assigned to Mid Triassic, whereas the Ab Haji Formation (sandstone) is referred to Lias. The lower contact of the Nayband Formation is marked by red bed as disconformarble contact while the upper lithostratigraphic contact with Ab Haji is gradational type. In general, the Central Iran Microcontinent is consisted of several blocks such as: Yazd, Posht Badam, Tabas, Kalmard and Lut (Aghanabati, 2004), while there are several records of tectonic evolution of the Central Iran Microcontinent (Kargaranbafghi et al, 2015; Chu et al, 2021; Abbaspour et al, 2024). With regard to active tectonic of the Central Iran as well as Cimmerian event the foraminiferal biostratigraphy is significant for Upper Triassic deposits (Nayband Formation). Some records of paleoenvironment and paleontological of the Nayband Formation were provided (Zamani et al, 2023; Shepherd et al, 2016; Bayetgoll and Daraei, 2017). It is necessary to note that the both litho-bio stratigraphic limits of the Upper Triassic/Lower Jurassic (Lias) is so significant not only in view of biostratigraphy but also in the field of micropaleontological features (Boudagher-Fadel, 2008). With regard to the previous studies (Zamaniyan et al, 2018; Mannani and Sherafat, 2021; Amirhassankhani et al, 2023; Hashemi Yazdi et al, 2023; Hadadi and Afghah, 2024), the foraminiferal biostratigraphy of the Upper Triassic deposits (Nayband Formation) is so significant for regional biostratigraphic correlation. For this reason, the studies of different sections of the Nayband Formation in other blocks of the Central Iran subcontinent can be important, and in the present study, its biostratigraphy has been studied in the Cheshmeh Gaz section located in the southern areas of the Posht Badam Block. However, recieving a foraminiferal biozonation which is affected by early Cimmerian event is the main goal of the present study. It should emphasized the mentioned event affected the paleoecological condition on foraminiferal environment. Moreover, compare of lithofacies and biostratigraphic data can clarify the mechanism of early Cimmerian effect in the Posht Badam Block.
<strong>Materials and Methods</strong>
In this research, to study the biostratigraphy of the Nayband Formation, the Cheshmeh Gaz stratigraphic section was selected and sampled in the Posht badam block. In order to biostratigraphy of the Nayband Formation, the lithostratigraphic contacts have been studied in detail. The thickness of the studied section is 180 meters. Based on the field characteristics of different layers, rock samples with the abbreviation Shm were numbered and sampled, and microscopic thin sections were prepared and studied. The sampling of the studied section has been conducted by lithofacies change with different sample interval. Since the Nayband Formation is composed of clastic and carbonates sediments, the foraminiferal contents are recognized just in carbonate sediments. According to Adams and Bourgeois, 1967, Donatomilanes, 1988, Loeblich and Tappan, 1988, Kobayashi et al. 2006, Boudagher -Fadel, 2008, Gale, 2012, Gale et al. (2016, 2020), the index foraminifers are identified and biozonation described.
<strong> </strong>
<strong>Results and Discussion</strong>
So far, no official biozonation has been provided for the deposits of the Nayband Formation in the Upper Triassic age range. But due to features such as abundance, high diversity, as well as a significant number of the first appearance and the last appearance of foraminiferal fauna in the mentioned age range, in terms of biostratigraphy, the mentioned fauna can be part of the very important paleobiotic elements of the Nayband Formation. Based on biostratigraphic studies, it is possible to understand the differences in different regions and identify specific fossil communities of each region. Also, in the studied area, because the lithological changes of Late Triassic deposits are directly related to the sedimentation and climatic conditions, and therefore the distribution of biological populations and existing biocenoses have undergone obvious changes to paleo-ecological developments. However, the foraminiferal association of the studied section represents the shallow water environment of the Nayband Formation. As mentioned before, the foraminiferal contents are recognizable in the carbonate units of the Nayband Formation. Generally, 25 species from 24 genera were identified and their age ranges were studied and finally the age was determined based on this. Foraminifera of the Nayband Formation in the studied section of Cheshmeh Gaz have a low abundance, but they have a significant diversity. Families such as Permodiscidae, Turrispirilinidae, Ammodiscidae and Frondicularidae have the highest abundance in the studied section in this research. Based on stratigraphic distribution of identified foraminifers, seven biozones were established.
<strong>Conclusion</strong>
Based on the biostratigraphic studies, there are seven biozones including <em>Ammodiscus parapriscus </em>Interval Zone,<em> Angulodiscus communis</em> Interval Zone, <em>Nodosaria nitidana</em> Interval Zone, <em>Turrispirllina minima</em> Interval Zone and <em>Trochammina almtalensis </em>Concurrence Rang Zone,<em> Triassina hantkeni</em> Concurrence Rang Zone,<em> Aulotortus</em> <em>bronimanni</em> Concurrence Rang Zone have been identified in the Upper Triassic deposits. Based on the identified biozones, the age range of the studied sequences is suggested to be late Norian-latest Rhaetian, which is equivalent to the Howz-e Khan and Qadir members of the Nayband Formation in central Iran. It is necessary to note that the identified foraminiferal biozones as well as vertical change in lithofacies of the Upper Triassic deposits (Nayband Formation) represent the change in sedimentary regime as well as foraminiferal composition which is assigned to early Cimmerian event. In order to detail understanding of Upper Triassic foraminiferal distribution, more investigation stratigraphic sections are required in the Central Iran Microcontinent.<strong>Introduction</strong>
As the oldest member of the Shemshak group, the Nayband formation has been widely outcropped in Central Iran. It has been important to geologists for a long time due to its significant coal deposits. Accordingly, the geological data about the Nayband Formation is relatively extent that geological studies have been carried out on almost all known outcrops of this formation. Considering that the deposits belonging to the Upper Triassic in the subcontinental blocks of Central Iran are different according to the performance of the previous Cimmerian event due to having separate characteristics, and due to the heterogeneous activities of the blocks of Central Iran, the mentioned deposits have various depositional environments (Seyed-Emami et al, 2004). Nayband Formation is sandwiched between carbonate sediment of Shotori Formation (below) and clastic sediment of Ab Haji Formation. Actually, the underalid formation (dolomite of Shotori Formation) is assigned to Mid Triassic, whereas the Ab Haji Formation (sandstone) is referred to Lias. The lower contact of the Nayband Formation is marked by red bed as disconformarble contact while the upper lithostratigraphic contact with Ab Haji is gradational type. In general, the Central Iran Microcontinent is consisted of several blocks such as: Yazd, Posht Badam, Tabas, Kalmard and Lut (Aghanabati, 2004), while there are several records of tectonic evolution of the Central Iran Microcontinent (Kargaranbafghi et al, 2015; Chu et al, 2021; Abbaspour et al, 2024). With regard to active tectonic of the Central Iran as well as Cimmerian event the foraminiferal biostratigraphy is significant for Upper Triassic deposits (Nayband Formation). Some records of paleoenvironment and paleontological of the Nayband Formation were provided (Zamani et al, 2023; Shepherd et al, 2016; Bayetgoll and Daraei, 2017). It is necessary to note that the both litho-bio stratigraphic limits of the Upper Triassic/Lower Jurassic (Lias) is so significant not only in view of biostratigraphy but also in the field of micropaleontological features (Boudagher-Fadel, 2008). With regard to the previous studies (Zamaniyan et al, 2018; Mannani and Sherafat, 2021; Amirhassankhani et al, 2023; Hashemi Yazdi et al, 2023; Hadadi and Afghah, 2024), the foraminiferal biostratigraphy of the Upper Triassic deposits (Nayband Formation) is so significant for regional biostratigraphic correlation. For this reason, the studies of different sections of the Nayband Formation in other blocks of the Central Iran subcontinent can be important, and in the present study, its biostratigraphy has been studied in the Cheshmeh Gaz section located in the southern areas of the Posht Badam Block. However, recieving a foraminiferal biozonation which is affected by early Cimmerian event is the main goal of the present study. It should emphasized the mentioned event affected the paleoecological condition on foraminiferal environment. Moreover, compare of lithofacies and biostratigraphic data can clarify the mechanism of early Cimmerian effect in the Posht Badam Block.
<strong>Materials and Methods</strong>
In this research, to study the biostratigraphy of the Nayband Formation, the Cheshmeh Gaz stratigraphic section was selected and sampled in the Posht badam block. In order to biostratigraphy of the Nayband Formation, the lithostratigraphic contacts have been studied in detail. The thickness of the studied section is 180 meters. Based on the field characteristics of different layers, rock samples with the abbreviation Shm were numbered and sampled, and microscopic thin sections were prepared and studied. The sampling of the studied section has been conducted by lithofacies change with different sample interval. Since the Nayband Formation is composed of clastic and carbonates sediments, the foraminiferal contents are recognized just in carbonate sediments. According to Adams and Bourgeois, 1967, Donatomilanes, 1988, Loeblich and Tappan, 1988, Kobayashi et al. 2006, Boudagher -Fadel, 2008, Gale, 2012, Gale et al. (2016, 2020), the index foraminifers are identified and biozonation described.
<strong> </strong>
<strong>Results and Discussion</strong>
So far, no official biozonation has been provided for the deposits of the Nayband Formation in the Upper Triassic age range. But due to features such as abundance, high diversity, as well as a significant number of the first appearance and the last appearance of foraminiferal fauna in the mentioned age range, in terms of biostratigraphy, the mentioned fauna can be part of the very important paleobiotic elements of the Nayband Formation. Based on biostratigraphic studies, it is possible to understand the differences in different regions and identify specific fossil communities of each region. Also, in the studied area, because the lithological changes of Late Triassic deposits are directly related to the sedimentation and climatic conditions, and therefore the distribution of biological populations and existing biocenoses have undergone obvious changes to paleo-ecological developments. However, the foraminiferal association of the studied section represents the shallow water environment of the Nayband Formation. As mentioned before, the foraminiferal contents are recognizable in the carbonate units of the Nayband Formation. Generally, 25 species from 24 genera were identified and their age ranges were studied and finally the age was determined based on this. Foraminifera of the Nayband Formation in the studied section of Cheshmeh Gaz have a low abundance, but they have a significant diversity. Families such as Permodiscidae, Turrispirilinidae, Ammodiscidae and Frondicularidae have the highest abundance in the studied section in this research. Based on stratigraphic distribution of identified foraminifers, seven biozones were established.
<strong>Conclusion</strong>
Based on the biostratigraphic studies, there are seven biozones including <em>Ammodiscus parapriscus </em>Interval Zone,<em> Angulodiscus communis</em> Interval Zone, <em>Nodosaria nitidana</em> Interval Zone, <em>Turrispirllina minima</em> Interval Zone and <em>Trochammina almtalensis </em>Concurrence Rang Zone,<em> Triassina hantkeni</em> Concurrence Rang Zone,<em> Aulotortus</em> <em>bronimanni</em> Concurrence Rang Zone have been identified in the Upper Triassic deposits. Based on the identified biozones, the age range of the studied sequences is suggested to be late Norian-latest Rhaetian, which is equivalent to the Howz-e Khan and Qadir members of the Nayband Formation in central Iran. It is necessary to note that the identified foraminiferal biozones as well as vertical change in lithofacies of the Upper Triassic deposits (Nayband Formation) represent the change in sedimentary regime as well as foraminiferal composition which is assigned to early Cimmerian event. In order to detail understanding of Upper Triassic foraminiferal distribution, more investigation stratigraphic sections are required in the Central Iran Microcontinent.https://esrj.sbu.ac.ir/article_105831_e4555f7aea7834eaef16bb6437c6e875.pdfShahid Beheshti UniversityResearches in Earth Sciences2008-829916220250522Impact of groundwater drawdown on land subsidence and creation of vulnerable areas in Neyshabur plainImpact of groundwater drawdown on land subsidence and creation of vulnerable areas in Neyshabur plain537110583010.48308/esrj.2025.105830FASeyed MostafaHasheminasabDepartment of Mineral and Groundwater Resources, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, IranHamid RezaNasseryDepartment of Mineral and Groundwater Resources, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran0000-0001-9901-0855FarshadAlijaniDepartment of Mineral and Groundwater Resources, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, IranJournal Article20250306<strong>Introduction</strong>
According to the definition of the American Geological Survey, the land subsidence Phenomenon is the collapsed or down warded settlement of the earth's surface, which can be had small displacement vector (Bates and Jackson, 1980). Land subsidence is a geological phenomenon caused to migrate slowly and horizontally part of the earth's surface layers (Hu et al, 2009). The subsidence phenomenon has the type of factors such as natural and unnatural factors which natural factors are included tectonic movements, limestone dissolution, karst sinkholes, magma discharge, organic soil oxidation, and natural soil compaction, which appear on a long time scale while unnatural factors are mainly caused by human activities. These factors like the severe and irreversible drop affected on groundwater level, oil and gas extraction created in a shorter period of time. The pore water pressure has been decreased by extraction of groundwater which is associated with pore water drainage. In other word, the stress caused to the weight of the upper layers gradually transferred the pore water to the grain structure. On the other hand, the influences of weight of sediments in the unsaturated zone will be increased when the submergence force of pore water is lost. Therefore, to compensate for this increase of pressure, the grain structure may change to accommodate this new stress situation. The porosity in the sediments is reduced to bear this additional pressure. This decrease in porosity is associated with a decrease in the volume of sediments, whose surface appearance is subsidence. The oldest known subsidence, based on information provided by UNESCO, has been occurred in Alabama (United States) in 1900. This phenomenon was along with the creation of cracks in the surface of the earth, has been observed in type of areas such as Italy, Japan, England, China, Thailand, Mexico and other parts of the world occurred with over-harvesting of ground water or oil wells. Due to many droughts in Iran (especially in the east and center), excessive exploitation of groundwater has increased that caused to increase the phenomenon of subsidence in many plains. Rahmanian (1986) prepared the first reports related to subsidence in Iran. The phenomenon of subsidence caused to the drop in the groundwater level has been reported in Rafsanjan plain in 1967 a longed with the phenomenon of tube formation in agricultural wells (Hosseini Milani, 1994). Komak-Panah (1997) considered the land subsidence in the Yazd-Ardakan plain as a result of excessive extraction of ground water, dissolution of salts in the soil, and washing of clay cement particles. Nassery (2005) has evaluated Hamedan Faminin plain that the average of annual drop of groundwater level during the nine-year (1991-1999) was about three meters and the amount of alluvial subsidence was different in parts of the plain which the average amount was 45 cm in the mentioned period.
The most of these sinkholes of Faminin Plain was created where made from limestone bedrock and irrigation of agricultural lands was utilized by flooding method.
Moafi and Rahnama (2006) have estimated the amount of land subsidence in the Rafsanjan plain using geographic information system and remote sensing, after correcting and reconstructing the statistics related to the wells in different months. Salehi et al (2012) have estimated the maximum land subsidence in Mahyar plain of Isfahan using InSAR data in the period of 2003-2006 that the subsidence was reached to 8.6 cm per year. The related results confirmed that the subsidence of this area was belonged to the drop in the groundwater level. Tabatabai and Mohseni Nasab (2014) reported that groundwater withdrawal, tectonic factors were also the main causes of subsidence of the Rafsanjan Plain. Parhizkar et al. (2015) have simulated the water level and have evaluated the subsidence of Damghan aquifer using two GMS and GEP models. The related results were shown that there was a significant relationship between the reduction of the groundwater level and the amount of subsidence, and the amount of recent extraction of water resources. Determining the amount and manner of subsidence is very important in its assessment and management. In order to monitoring and measurement of the subsidence rate in the Neyshabour Plain during the period of 2016, there were various methods such as Spirit Level Global Positioning System (GPS) and Artificial Radar Interferometry(SAR).
<strong>Materials and Methods</strong>
In order to determine the relationship between the changes of the groundwater level and the subsidence phenomenon in the Neyshabur Plain, the geological and climatical conditions of the area were evaluated and interpreted. Then, the information related to 54 observation wells during 30-year of water period (1987 to 2017) was collected and their corresponding hydrograph have been prepared. The time period 2014/08 to 2018/12 has been prepared using GMTSAR software in Linux environment (Geological and Mineral Exploration Organization of the country, GMTSAR 2020). With comparing the position of the settlement zones with the map of the groundwater level, we have investigated the relationship between two parameters and have analyzed the evidence and consequences of this phenomenon in the studied area.
<strong> </strong>
<strong>Results and Discussion</strong>
<strong>Information related to observation wells</strong>
According to the hydrograph of the observation wells, the fluctuations of the groundwater level in the observation wells can be classified into three groups: A, B, and C.
-In the observation wells of group, A, the groundwater level did not fluctuate or its fluctuation was very low. This group of wells are located in the northwest area of the plain and they receive very good surface and ground nutrition, so that despite the significant extraction of ground water in their area, they do not show much drop.
-In the observation wells of group B, due to excessive withdrawal from the aquifer in their area, the level of ground water has been constantly falling and the decline was uniform. The observation well of South Hossein Abad Jangal is representative of this group of wells.
-In the observation wells of group C, the ground water level has a sinusoidal downward fluctuation, which means that their water level has decreased, but during the wet season, it has risen as a result of increasing the amount of feeding and reducing harvesting. During the dry period, with the increase in the amount of harvesting, the water level has fallen again, and the resulting drop is much more than the increase during the wet period. Therefore, the water level has dropped more in each water year than the previous year.
<strong>Information related to satellite images</strong>
The evaluation of subsidence maps prepared in Neyshabour plain have been shown that the highest rate of subsidence in the significant period (2014/08 to 2016/03) was 15.4 cm per year and it was 14.8 cm of subsidence during 2016/04 to 2018/12. It has been over the years. In order to investigate the phenomenon of subsidence more closely and to determine the area of the areas with high subsidence rate, the maps of the average subsidence rate obtained by the radar interferometry method have been classified. The distance between the ranks is considered to be three centimeters per year, based on which six ranks are defined.
The critical areas of subsidence in the Neyshabur Plain have been marked with black oval marks. According to the evaluation of this map, there were four areas with a high subsidence rate (more than 9 cm per year).
-The critical area in the northeast of the plain: this area is located in the east of Neyshabur city and there was the maximum subsidence rate of the plain (14.8 cm/year) where there are the main road and the national railway line of Mashhad-Tehran and also most of the industries area are located in the Neyshabur Plain.
-Central critical area: This area is placed in the west and southwest of Neyshabur city and there is the maximum subsidence rate of the plain as 12 cm per year. The main road, the national Mashhad-Tehran railway line and the most of the farm lands are located in this area.
-Western critical area: there is the maximum subsidence rate of the plain (12 cm per year) in the west of
Neyshabur section. The main road and the national Mashhad-Tehran railway line have been shown there and the oldest traces of cracks caused by subsidence were shown in Bazoband village.
-South critical area: located in the south and southeast of Neyshabur Plain and the maximum subsidence amount is 12 cm per year. Agricultural activities have been grown up widely in this part of the plain.
<strong>Geomorphic implications of the study area</strong>
The subsidence related to exploration of groundwater resources can be caused to many of the economic, social, and environmental damages. The type, extent and severity of these damages depend on the amount of subsidence and the affected zone. As the annual surplus of water withdrawal of the non-renewable sources are more than its replacement by rains, this issue can be caused to the risk of spreading subsidence in other parts of the plain. One of the most important consequences of subsidence can be mentioned continuous longitudinal cracks, interrupted cracks, round holes, wide pits and sinkholes. Longitudinal cracks are observed in many parts of the Plain margin which were formed by the joining of discontinuous cracks with a definite extension. Discontinuous cracks which are continued in the initial steps of creation of longitudinal cracks. After rainfall and flooding create continuous longitudinal cracks (Rokni et al, 2015). Circular holes are the result of subsidence of the lower layers and can be seen in parts of the edge of the plain. The creation of countless cracks has created a very high vulnerability potential for transportation infrastructures, power transmission lines, industrial areas and even residential areas. According to the map of vulnerable areas, there are four areas with a high rate of subsidence and vulnerability potential in the northeastern, central, western and southern parts of Neyshabur Plain, and important infrastructures such as oil and gas transmission lines, railway lines, urban transmission lines and Intercity corresponds to these areas. It is obvious that if not controlled, it will impose life and financial risks in the not too distant future.
<strong>Conclusion</strong>
Generally, what emerges from the results of the studies of ground water level changes in observation wells and the satellite interferometric method in this research is that in the Neyshabur plain, there are four critical areas in the northeast, central critical, western critical and southern critical areas with high rates of subsidence (more than from 9 cm per year. The highest amount of subsidence has occurred in the east of Neyshabur city with the maximum rate of subsidence of the plain (14.8 cm per year), where the main road, the Mashhad-Tehran national railway line and the major part of the industries of the Neyshabur plain are located in this area. are located. In the other three critical areas, the maximum rate of subsidence is 12 cm per year. The graphs of the rate of groundwater level drop and the rate of subsidence of the plain show that the drop of the groundwater level has a significant effect on the land subsidence. In a large part of the Neyshabur Plain, the rate of drop 30 years has been more than 20 meters and the four subsidence zones correspond to the parts of the plain where the drop in the groundwater level has been more than 30 meters. The results of this research show that water withdrawal exceeds the recovery capacity of the aquifer as one It is one of the main reasons for subsidence in the plain, so it is necessary to pay special attention to the management of ground water resources. The consequences of the subsidence phenomenon in the plain have been the creation of continuous and interrupted longitudinal cracks, circular holes and wide pits. The expansion of these cracks to the main road, national railway line and oil and gas transmission lines may cause various risks.<strong>Introduction</strong>
According to the definition of the American Geological Survey, the land subsidence Phenomenon is the collapsed or down warded settlement of the earth's surface, which can be had small displacement vector (Bates and Jackson, 1980). Land subsidence is a geological phenomenon caused to migrate slowly and horizontally part of the earth's surface layers (Hu et al, 2009). The subsidence phenomenon has the type of factors such as natural and unnatural factors which natural factors are included tectonic movements, limestone dissolution, karst sinkholes, magma discharge, organic soil oxidation, and natural soil compaction, which appear on a long time scale while unnatural factors are mainly caused by human activities. These factors like the severe and irreversible drop affected on groundwater level, oil and gas extraction created in a shorter period of time. The pore water pressure has been decreased by extraction of groundwater which is associated with pore water drainage. In other word, the stress caused to the weight of the upper layers gradually transferred the pore water to the grain structure. On the other hand, the influences of weight of sediments in the unsaturated zone will be increased when the submergence force of pore water is lost. Therefore, to compensate for this increase of pressure, the grain structure may change to accommodate this new stress situation. The porosity in the sediments is reduced to bear this additional pressure. This decrease in porosity is associated with a decrease in the volume of sediments, whose surface appearance is subsidence. The oldest known subsidence, based on information provided by UNESCO, has been occurred in Alabama (United States) in 1900. This phenomenon was along with the creation of cracks in the surface of the earth, has been observed in type of areas such as Italy, Japan, England, China, Thailand, Mexico and other parts of the world occurred with over-harvesting of ground water or oil wells. Due to many droughts in Iran (especially in the east and center), excessive exploitation of groundwater has increased that caused to increase the phenomenon of subsidence in many plains. Rahmanian (1986) prepared the first reports related to subsidence in Iran. The phenomenon of subsidence caused to the drop in the groundwater level has been reported in Rafsanjan plain in 1967 a longed with the phenomenon of tube formation in agricultural wells (Hosseini Milani, 1994). Komak-Panah (1997) considered the land subsidence in the Yazd-Ardakan plain as a result of excessive extraction of ground water, dissolution of salts in the soil, and washing of clay cement particles. Nassery (2005) has evaluated Hamedan Faminin plain that the average of annual drop of groundwater level during the nine-year (1991-1999) was about three meters and the amount of alluvial subsidence was different in parts of the plain which the average amount was 45 cm in the mentioned period.
The most of these sinkholes of Faminin Plain was created where made from limestone bedrock and irrigation of agricultural lands was utilized by flooding method.
Moafi and Rahnama (2006) have estimated the amount of land subsidence in the Rafsanjan plain using geographic information system and remote sensing, after correcting and reconstructing the statistics related to the wells in different months. Salehi et al (2012) have estimated the maximum land subsidence in Mahyar plain of Isfahan using InSAR data in the period of 2003-2006 that the subsidence was reached to 8.6 cm per year. The related results confirmed that the subsidence of this area was belonged to the drop in the groundwater level. Tabatabai and Mohseni Nasab (2014) reported that groundwater withdrawal, tectonic factors were also the main causes of subsidence of the Rafsanjan Plain. Parhizkar et al. (2015) have simulated the water level and have evaluated the subsidence of Damghan aquifer using two GMS and GEP models. The related results were shown that there was a significant relationship between the reduction of the groundwater level and the amount of subsidence, and the amount of recent extraction of water resources. Determining the amount and manner of subsidence is very important in its assessment and management. In order to monitoring and measurement of the subsidence rate in the Neyshabour Plain during the period of 2016, there were various methods such as Spirit Level Global Positioning System (GPS) and Artificial Radar Interferometry(SAR).
<strong>Materials and Methods</strong>
In order to determine the relationship between the changes of the groundwater level and the subsidence phenomenon in the Neyshabur Plain, the geological and climatical conditions of the area were evaluated and interpreted. Then, the information related to 54 observation wells during 30-year of water period (1987 to 2017) was collected and their corresponding hydrograph have been prepared. The time period 2014/08 to 2018/12 has been prepared using GMTSAR software in Linux environment (Geological and Mineral Exploration Organization of the country, GMTSAR 2020). With comparing the position of the settlement zones with the map of the groundwater level, we have investigated the relationship between two parameters and have analyzed the evidence and consequences of this phenomenon in the studied area.
<strong> </strong>
<strong>Results and Discussion</strong>
<strong>Information related to observation wells</strong>
According to the hydrograph of the observation wells, the fluctuations of the groundwater level in the observation wells can be classified into three groups: A, B, and C.
-In the observation wells of group, A, the groundwater level did not fluctuate or its fluctuation was very low. This group of wells are located in the northwest area of the plain and they receive very good surface and ground nutrition, so that despite the significant extraction of ground water in their area, they do not show much drop.
-In the observation wells of group B, due to excessive withdrawal from the aquifer in their area, the level of ground water has been constantly falling and the decline was uniform. The observation well of South Hossein Abad Jangal is representative of this group of wells.
-In the observation wells of group C, the ground water level has a sinusoidal downward fluctuation, which means that their water level has decreased, but during the wet season, it has risen as a result of increasing the amount of feeding and reducing harvesting. During the dry period, with the increase in the amount of harvesting, the water level has fallen again, and the resulting drop is much more than the increase during the wet period. Therefore, the water level has dropped more in each water year than the previous year.
<strong>Information related to satellite images</strong>
The evaluation of subsidence maps prepared in Neyshabour plain have been shown that the highest rate of subsidence in the significant period (2014/08 to 2016/03) was 15.4 cm per year and it was 14.8 cm of subsidence during 2016/04 to 2018/12. It has been over the years. In order to investigate the phenomenon of subsidence more closely and to determine the area of the areas with high subsidence rate, the maps of the average subsidence rate obtained by the radar interferometry method have been classified. The distance between the ranks is considered to be three centimeters per year, based on which six ranks are defined.
The critical areas of subsidence in the Neyshabur Plain have been marked with black oval marks. According to the evaluation of this map, there were four areas with a high subsidence rate (more than 9 cm per year).
-The critical area in the northeast of the plain: this area is located in the east of Neyshabur city and there was the maximum subsidence rate of the plain (14.8 cm/year) where there are the main road and the national railway line of Mashhad-Tehran and also most of the industries area are located in the Neyshabur Plain.
-Central critical area: This area is placed in the west and southwest of Neyshabur city and there is the maximum subsidence rate of the plain as 12 cm per year. The main road, the national Mashhad-Tehran railway line and the most of the farm lands are located in this area.
-Western critical area: there is the maximum subsidence rate of the plain (12 cm per year) in the west of
Neyshabur section. The main road and the national Mashhad-Tehran railway line have been shown there and the oldest traces of cracks caused by subsidence were shown in Bazoband village.
-South critical area: located in the south and southeast of Neyshabur Plain and the maximum subsidence amount is 12 cm per year. Agricultural activities have been grown up widely in this part of the plain.
<strong>Geomorphic implications of the study area</strong>
The subsidence related to exploration of groundwater resources can be caused to many of the economic, social, and environmental damages. The type, extent and severity of these damages depend on the amount of subsidence and the affected zone. As the annual surplus of water withdrawal of the non-renewable sources are more than its replacement by rains, this issue can be caused to the risk of spreading subsidence in other parts of the plain. One of the most important consequences of subsidence can be mentioned continuous longitudinal cracks, interrupted cracks, round holes, wide pits and sinkholes. Longitudinal cracks are observed in many parts of the Plain margin which were formed by the joining of discontinuous cracks with a definite extension. Discontinuous cracks which are continued in the initial steps of creation of longitudinal cracks. After rainfall and flooding create continuous longitudinal cracks (Rokni et al, 2015). Circular holes are the result of subsidence of the lower layers and can be seen in parts of the edge of the plain. The creation of countless cracks has created a very high vulnerability potential for transportation infrastructures, power transmission lines, industrial areas and even residential areas. According to the map of vulnerable areas, there are four areas with a high rate of subsidence and vulnerability potential in the northeastern, central, western and southern parts of Neyshabur Plain, and important infrastructures such as oil and gas transmission lines, railway lines, urban transmission lines and Intercity corresponds to these areas. It is obvious that if not controlled, it will impose life and financial risks in the not too distant future.
<strong>Conclusion</strong>
Generally, what emerges from the results of the studies of ground water level changes in observation wells and the satellite interferometric method in this research is that in the Neyshabur plain, there are four critical areas in the northeast, central critical, western critical and southern critical areas with high rates of subsidence (more than from 9 cm per year. The highest amount of subsidence has occurred in the east of Neyshabur city with the maximum rate of subsidence of the plain (14.8 cm per year), where the main road, the Mashhad-Tehran national railway line and the major part of the industries of the Neyshabur plain are located in this area. are located. In the other three critical areas, the maximum rate of subsidence is 12 cm per year. The graphs of the rate of groundwater level drop and the rate of subsidence of the plain show that the drop of the groundwater level has a significant effect on the land subsidence. In a large part of the Neyshabur Plain, the rate of drop 30 years has been more than 20 meters and the four subsidence zones correspond to the parts of the plain where the drop in the groundwater level has been more than 30 meters. The results of this research show that water withdrawal exceeds the recovery capacity of the aquifer as one It is one of the main reasons for subsidence in the plain, so it is necessary to pay special attention to the management of ground water resources. The consequences of the subsidence phenomenon in the plain have been the creation of continuous and interrupted longitudinal cracks, circular holes and wide pits. The expansion of these cracks to the main road, national railway line and oil and gas transmission lines may cause various risks.https://esrj.sbu.ac.ir/article_105830_c8ff7ad4fba62bb024d323345b5c58e4.pdfShahid Beheshti UniversityResearches in Earth Sciences2008-829916220250522Evaluation and analysis of resilience of 29 neighborhoods in Tehran's district 5 against environmental crises based on ecosystem approachEvaluation and analysis of resilience of 29 neighborhoods in Tehran's district 5 against environmental crises based on ecosystem approach728910547410.48308/esrj.2024.223388.1065FAVafaGhaem MaghamiDepartment of Environmental Planning, Faculty of Environment, University of Tehran, Tehran, IranAhmadNohegarDepartment of Disaster Engineering, Education and Environmental Systems, Faculty of Environment, University of Tehran, Tehran, IranMohamad JavadAmiriDepartment of Disaster Engineering, Education and Environmental Systems, Faculty of Environment, University of Tehran, Tehran, Iran0000-0003-1748-9036Journal Article20240427<strong>Introduction</strong>
The metropolitan city of Tehran, as the political capital of Iran, has a population exceeding 8 million and a population density of 12,200 individuals per square kilometer. Spanning an area of approximately 751 square kilometers, Tehran is situated at an elevation ranging from 900 to 1800 meters in the southern foothills of the Alborz Mountains. This high population density, coupled with exposure to various environmental hazards, has rendered crisis management in this city a complex and multifaceted challenge. Environmental crises such as earthquakes, floods, fires, water and air pollution, and land subsidence have exacerbated Tehran’s environmental vulnerability, posing substantial risks to urban security and public welfare, particularly in highly susceptible areas such as District 5. A comprehensive understanding of the dimensions of vulnerability in District 5 against environmental crises is imperative for devising effective management strategies aimed at mitigating vulnerability and risk while enhancing urban resilience. Accordingly, the primary objective of this study is to assess the level of urban resilience in District 5 of Tehran concerning environmental crises. Additionally, this research seeks to identify structurally and functionally deficient neighborhoods in order to propose evidence-based and practical strategies for addressing these weaknesses and enhancing resilience. The findings of this study contribute to a deeper understanding of the challenges ahead and facilitate targeted planning and optimal resource allocation.
<strong> </strong>
<strong>Materials and Methods</strong>
The study area comprises District 5 of Tehran Municipality, selected as a representative case due to its distinct characteristics, including its exposure to multiple environmental hazards. A mixed-method approach was employed to assess urban resilience against environmental crises, encompassing earthquakes, floods, subsidence, and fires. Data were obtained through expert interviews with urban planners and environmental specialists, literature reviews, examination of relevant documents and records, and field observations. In this study, urban resilience indicators were employed to evaluate the resilience of neighborhoods in District 5 of Tehran against environmental crises. The assessment was conducted based on four main criteria: socio-economic, physical-structural, accessibility, and environmental, incorporating 37 sub-criteria. Each sub-criterion was mapped as a distinct data layer using ArcGIS software. Subsequently, fuzzy logic operators were applied to standardize (fuzzify) the data by converting values into a range between zero and one. The Analytical Network Process (ANP) was employed to determine the relative weight and significance of each criterion and sub-criterion, enabling the consideration of interdependencies among them.
The spatial layers corresponding to each criterion were integrated and analyzed using fuzzy logic operators.
Finally, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) was utilized to rank the neighborhoods of District 5, and a classical clustering approach was applied to classify them based on their resilience levels.
<strong> </strong>
<strong>Results and Discussion</strong>
The results indicate that the socio-economic criterion, with a fuzzy membership degree of 0.45, is the most influential determinant of urban resilience in District 5 of Tehran. Factors such as the structural integrity of residential buildings, the presence or absence of informal settlements, accessibility to essential services (e.g., healthcare, educational institutions), exposure to flood-prone areas, and land-use classification significantly influence the resilience levels of this district. From a spatial perspective, neighborhoods such as Shahin, Northern Jannat Abad, and Al-Mahdi, located in the northern part of the district, demonstrate the highest levels of resilience. This resilience is attributed to factors such as robust building structures, the absence of informal settlements, sufficient distance from flood pathways and pollution sources, availability of open spaces, and optimal access to service centers. Conversely, neighborhoods such as Ekbatan, Bimeh, and Kan exhibit the lowest resilience levels, highlighting critical areas for intervention. The least squares regression indicated that the fuzzy algebraic sum operator (SUM) demonstrated the best performance in detecting neighborhood resilience against environmental crises.
<strong> </strong>
<strong>Conclusion</strong>
The southern neighborhoods of District 5, including Ekbatan, Bimeh, Kan, Apadana, and Eram, exhibit lower resilience due to high population and building densities, the presence of aging infrastructure and informal settlements, environmental pollution, and socio-economic and infrastructural deficiencies, along with limited access to essential services. These findings underscore the heightened vulnerability of these neighborhoods to environmental crises, indicating their potential to sustain substantial damage and loss in the event of a disaster. This study provides critical insights by systematically identifying weaknesses and vulnerabilities within District 5, thereby equipping urban policymakers and decision-makers with essential data for informed decision-making. The adoption of targeted interventions, such as infrastructure enhancement, urban renewal, public awareness campaigns, and the reinforcement of crisis management systems, can significantly bolster resilience levels. Future strategies should prioritize investment in upgrading infrastructure, retrofitting vulnerable urban fabrics, increasing public preparedness, and strengthening disaster management frameworks to enhance overall urban resilience.<strong>Introduction</strong>
The metropolitan city of Tehran, as the political capital of Iran, has a population exceeding 8 million and a population density of 12,200 individuals per square kilometer. Spanning an area of approximately 751 square kilometers, Tehran is situated at an elevation ranging from 900 to 1800 meters in the southern foothills of the Alborz Mountains. This high population density, coupled with exposure to various environmental hazards, has rendered crisis management in this city a complex and multifaceted challenge. Environmental crises such as earthquakes, floods, fires, water and air pollution, and land subsidence have exacerbated Tehran’s environmental vulnerability, posing substantial risks to urban security and public welfare, particularly in highly susceptible areas such as District 5. A comprehensive understanding of the dimensions of vulnerability in District 5 against environmental crises is imperative for devising effective management strategies aimed at mitigating vulnerability and risk while enhancing urban resilience. Accordingly, the primary objective of this study is to assess the level of urban resilience in District 5 of Tehran concerning environmental crises. Additionally, this research seeks to identify structurally and functionally deficient neighborhoods in order to propose evidence-based and practical strategies for addressing these weaknesses and enhancing resilience. The findings of this study contribute to a deeper understanding of the challenges ahead and facilitate targeted planning and optimal resource allocation.
<strong> </strong>
<strong>Materials and Methods</strong>
The study area comprises District 5 of Tehran Municipality, selected as a representative case due to its distinct characteristics, including its exposure to multiple environmental hazards. A mixed-method approach was employed to assess urban resilience against environmental crises, encompassing earthquakes, floods, subsidence, and fires. Data were obtained through expert interviews with urban planners and environmental specialists, literature reviews, examination of relevant documents and records, and field observations. In this study, urban resilience indicators were employed to evaluate the resilience of neighborhoods in District 5 of Tehran against environmental crises. The assessment was conducted based on four main criteria: socio-economic, physical-structural, accessibility, and environmental, incorporating 37 sub-criteria. Each sub-criterion was mapped as a distinct data layer using ArcGIS software. Subsequently, fuzzy logic operators were applied to standardize (fuzzify) the data by converting values into a range between zero and one. The Analytical Network Process (ANP) was employed to determine the relative weight and significance of each criterion and sub-criterion, enabling the consideration of interdependencies among them.
The spatial layers corresponding to each criterion were integrated and analyzed using fuzzy logic operators.
Finally, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) was utilized to rank the neighborhoods of District 5, and a classical clustering approach was applied to classify them based on their resilience levels.
<strong> </strong>
<strong>Results and Discussion</strong>
The results indicate that the socio-economic criterion, with a fuzzy membership degree of 0.45, is the most influential determinant of urban resilience in District 5 of Tehran. Factors such as the structural integrity of residential buildings, the presence or absence of informal settlements, accessibility to essential services (e.g., healthcare, educational institutions), exposure to flood-prone areas, and land-use classification significantly influence the resilience levels of this district. From a spatial perspective, neighborhoods such as Shahin, Northern Jannat Abad, and Al-Mahdi, located in the northern part of the district, demonstrate the highest levels of resilience. This resilience is attributed to factors such as robust building structures, the absence of informal settlements, sufficient distance from flood pathways and pollution sources, availability of open spaces, and optimal access to service centers. Conversely, neighborhoods such as Ekbatan, Bimeh, and Kan exhibit the lowest resilience levels, highlighting critical areas for intervention. The least squares regression indicated that the fuzzy algebraic sum operator (SUM) demonstrated the best performance in detecting neighborhood resilience against environmental crises.
<strong> </strong>
<strong>Conclusion</strong>
The southern neighborhoods of District 5, including Ekbatan, Bimeh, Kan, Apadana, and Eram, exhibit lower resilience due to high population and building densities, the presence of aging infrastructure and informal settlements, environmental pollution, and socio-economic and infrastructural deficiencies, along with limited access to essential services. These findings underscore the heightened vulnerability of these neighborhoods to environmental crises, indicating their potential to sustain substantial damage and loss in the event of a disaster. This study provides critical insights by systematically identifying weaknesses and vulnerabilities within District 5, thereby equipping urban policymakers and decision-makers with essential data for informed decision-making. The adoption of targeted interventions, such as infrastructure enhancement, urban renewal, public awareness campaigns, and the reinforcement of crisis management systems, can significantly bolster resilience levels. Future strategies should prioritize investment in upgrading infrastructure, retrofitting vulnerable urban fabrics, increasing public preparedness, and strengthening disaster management frameworks to enhance overall urban resilience.https://esrj.sbu.ac.ir/article_105474_47106e7f03b49d00f9641eba61a0245e.pdfShahid Beheshti UniversityResearches in Earth Sciences2008-829916220250522An observational study of radiation and subsidence temperature inversions in Bandar Abbas (2005-2024)An observational study of radiation and subsidence temperature inversions in Bandar Abbas (2005-2024)9011110582410.48308/esrj.2025.237747.1241FAMohammadMoradiResearch Institute of Meteorology and Atmospheric Science (RIMAS), Tehran, Iran0000-0002-5356-8578ZahraGhassabiResearch Institute of Meteorology and Atmospheric Science (RIMAS), Tehran, Iran0000-0002-0791-3430ParvizRezazadehIRIMet Organization weather forecast consultant, Tehran, IranJournal Article20241130<strong>Introduction</strong>
Under normal conditions, the temperature usually decreases with increase in altitude in the troposphere at a rate of 6.5 degree centigrade in one Kilometer. Sometimes the normal temperature lapse rate reverses and it increases with height rather than decreasing. The temperature inversion is characterized by the increase in temperature with height which is usually associated with air pollution. In rural and industrial areas, the temperature inversion plays an important role in events within the atmospheric boundary layer particularly in surface radiation balance and vertical mixing depth. This phenomenon intensifies the stable air layer close to the Earth’s surface, trapes the pollutants and impedes the dispersion into the free atmosphere. Temperature inversion is classified as Upper and lower inversions on the basis of the height from the earth's surface and the type of air circulation. Upper air inversion is a thermal or mechanical one. Thermal upper inversion is caused by the presence of ozone layer over the tropopause in the stratosphere. The mechanical inversion happens at higher levels of the atmosphere due to air subsidence, turbulence and convective mechanism. Lower air inversion is a radiation and also due to advection (Frontal, Valley and Surface Inversion). Radiation inversion is caused by excessive nocturnal cooling of the ground surface due to rapid heat loss from the ground through the outgoing long-wave radiation. The radiation inversions is marked by a stable atmospheric conditions, clear sky and low wind speeds which results in the accumulation of pollutants near the surface. The temperature inversion studies in warm and humid climate are scarce, and the relationship between temperature inversions and the meteorological variables are still not well understood. Because of the geographical location and special weather conditions in Bandar Abbas station, little is known about the relationship between temperature inversions and meteorological variables in this station, which has a warm and humid climate. The objective of this study is to analyze the frequency, depth and intensity of the radiation and subsidence inversions observed in the Bandar Abbas station in southern part of Iran.
<strong>Materials and Methods</strong>
Bandar Abbas station (56.37 °E, 27.22 °N) is a coastal station situated approximately 2.5 km from the seashore and at 10m elevation. Due to its location, Bandar Abbas has a warm and humid climate with frequent Mist and fog throughout the year. Summer in Bandar Abbas is long and warm with prevailing northly wind at night and southerly wind during the day time. Highest maximum temperature of this station at in season is 43-48 °C, and lasts for 7 months from April to October. Cold season in this station is short (5 months from November to March) with moderate temperatures (17 to 24 °C).
The lowest minimum temperature of this season is less than 10 °C. The lowest temperature is 2.0°C which is recorded in 27 December 1972 and the highest temperatures is 48.0°C which is recorded on 28th of June 1976 (30 July 1978). The mean annual precipitation of this station is 170.7 mm and the highest 24hrs rainfall is 211.0 mm which is recorded in 24 January 1979. In this study, the nocturnal temperature inversions (radiation inversion and subsidence inversion) are identified by the analysis of Bandar Abbas upper-air station radiosonde data at 00Z from 17 October 2005 to 08 July 2024 and then analyzed. The radiosonde measurements provide high resolution vertical atmospheric temperature which is very appropriate to study the temperature inversions. Temperature inversion detection was done by RAOB application. The analysis includes frequency, depth, and strength of the inversions on a monthly and annual basis. After detecting the radiative inversion layer, first of all the best curve was fitted to the revealed data and then based on the values of 5, 25, 50, 75 and 95% of the fitted curve, the depth and intensity values of radiative inversion. Base on the Delta-Z and Delta-T, the radiation inversion depth and intensity were classified and their annual and monthly occurrence frequencies are analyzed. The very weak, weak, moderate, strong and very strong inversions are characterized by the Delta-T which is less than 1.8, 3.3, 5.2, 8.8 and greater than 8.8 °C respectively. Furthermore, the very shallow, shallow, moderate, deep and very deep inversions are Characterized by the Delta-Z, which is less than 74, 128, 232, 668 and greater than 668 meter respectively.
<strong>Results and Discussion</strong>
The analysis of the nighttime temperature inversions in Bandar Abbas station reveals that at least in half of the summer days (June, July, August, September), radiation inversion was not developed and a uniform monthly frequency distribution was observed. Occurrence of radiation inversion at 85% of the days in October, November, December, January, February and March, was detected. The longer winter nights and the southerly radiation inversion wind of the sea breeze toward the land during the daytime and the northerly wind of the land breeze to the sea at night can provide suitable conditions for creating the radiation inversion of Bandar Abbas. In this station, the frequency of days without subsidence inversion in hot months, is less than in cold months of the year. This condition is due to the establishment of subtropical highs in the region. The frequency of deep and very deep radiative inversion in Bandar Abbas station is higher in the warm months of the year than in other months but the frequency of radiative inversion with moderate depth in the months of January, February, November and December are more than other months. The reason for this difference is the combination of the advection inversion created by the return branch of the sea breeze to land in the warm season with the nighttime radiation inversion. The results of the analysis of radiation inversion intensity showed that the frequency of very strong radiation inversion in the months of November, December, and January is higher than the intense and moderate inversions.The classification of the radiation inversions according to the magnitude of depth (Delta-Z) indicates the prevalence of very shallow (20.5%), shallow (27.5%) and moderate (23.7) inversions in Bandar Abbas. Also, frequency of deep and very deep inversions was estimated 15.9% and 8.5% respectively. The analysis of the frequencies base on the intensity (Delta-T), indicated that the frequency of very weak, weak and moderate radiation inversions in Bandar Abbas is 20.5%, 21.2% and 25.2% respectively. The frequency of strong and very strong inversions was estimated 21.3% and 4.2% respectively. The results showed that the upper levels inversion frequency at Bandar Abbas station was about 83.2% that 11.1% that is of the thermal inversion, 47.9% that is of subsidence inversion and 24.2% that is of the advection inversion.
<strong> </strong>
<strong>Conclusion</strong>
The aim of this work is to analyze and classification characteristics of traditional inversion in Bandar Abbas station. Temperature inversion refers to the increase of air temperature with height along the vertical atmospheric column. For this purpose, the nighttime radiation inversion and subsidence inversion are identified from the analysis of Bandar Abbas upper-air station radiosonde data at 00Z from 17 October 2005 to 08 July 2024 and then analyzed. Detection of temperature inversion was done with RAOB application. The analysis includes frequency, depth, and strength of inversions on a monthly and annual basis. Based on the study results, it is found that the height of radiation inversion in Bandar Abbas has not exceeded 1500 meters in this statistical period. In the months of July and August, the highest frequency of radiation inversion is in the high of 501-700 meters but in the rest of
the months and in the whole period, the highest frequency is estimated in the high of 51-150 meters. Also, In the statistical period of 2005-2024, the maximum height of the radiation inversion ceiling of Bandar Abbas station is 1420 meters in May, 1428 meters in June, and 1413 meters in July. The results in Bandar Abbas station reveals that at least in half of the summer days (June, July, August, September) a radiation inversion was not developed. In addition, at in 85% of the days October, November, December, January, February and March a radiation inversion was detected. In winter the long length of winter nights and the southerly wind of the sea breeze to the land during the day and the northerly wind of the land breeze to the sea at night can provide suitable conditions for creating the radiation inversion in Bandar Abbas. In this station, the frequency of days without subsidence inversion in hot months, is less than in cold months of the year. This condition is due to the establishment of subtropical highs in the region. In addition, the frequency of deep and very deep radiative inversion in Bandar Abbas station is higher in the warm months of the year than in other months but the frequency of radiative inversion with moderate depth in the months of January, February, November and December are more than other months. The reason for this difference is the combination of the advection inversion created by the return branch of the sea breeze to land in the warm season with the nighttime radiation inversion. The results of the analysis of radiation inversion intensity showed that the frequency of very strong radiation inversion in November, December, and January is higher than the strong and moderate inversions.<strong>Introduction</strong>
Under normal conditions, the temperature usually decreases with increase in altitude in the troposphere at a rate of 6.5 degree centigrade in one Kilometer. Sometimes the normal temperature lapse rate reverses and it increases with height rather than decreasing. The temperature inversion is characterized by the increase in temperature with height which is usually associated with air pollution. In rural and industrial areas, the temperature inversion plays an important role in events within the atmospheric boundary layer particularly in surface radiation balance and vertical mixing depth. This phenomenon intensifies the stable air layer close to the Earth’s surface, trapes the pollutants and impedes the dispersion into the free atmosphere. Temperature inversion is classified as Upper and lower inversions on the basis of the height from the earth's surface and the type of air circulation. Upper air inversion is a thermal or mechanical one. Thermal upper inversion is caused by the presence of ozone layer over the tropopause in the stratosphere. The mechanical inversion happens at higher levels of the atmosphere due to air subsidence, turbulence and convective mechanism. Lower air inversion is a radiation and also due to advection (Frontal, Valley and Surface Inversion). Radiation inversion is caused by excessive nocturnal cooling of the ground surface due to rapid heat loss from the ground through the outgoing long-wave radiation. The radiation inversions is marked by a stable atmospheric conditions, clear sky and low wind speeds which results in the accumulation of pollutants near the surface. The temperature inversion studies in warm and humid climate are scarce, and the relationship between temperature inversions and the meteorological variables are still not well understood. Because of the geographical location and special weather conditions in Bandar Abbas station, little is known about the relationship between temperature inversions and meteorological variables in this station, which has a warm and humid climate. The objective of this study is to analyze the frequency, depth and intensity of the radiation and subsidence inversions observed in the Bandar Abbas station in southern part of Iran.
<strong>Materials and Methods</strong>
Bandar Abbas station (56.37 °E, 27.22 °N) is a coastal station situated approximately 2.5 km from the seashore and at 10m elevation. Due to its location, Bandar Abbas has a warm and humid climate with frequent Mist and fog throughout the year. Summer in Bandar Abbas is long and warm with prevailing northly wind at night and southerly wind during the day time. Highest maximum temperature of this station at in season is 43-48 °C, and lasts for 7 months from April to October. Cold season in this station is short (5 months from November to March) with moderate temperatures (17 to 24 °C).
The lowest minimum temperature of this season is less than 10 °C. The lowest temperature is 2.0°C which is recorded in 27 December 1972 and the highest temperatures is 48.0°C which is recorded on 28th of June 1976 (30 July 1978). The mean annual precipitation of this station is 170.7 mm and the highest 24hrs rainfall is 211.0 mm which is recorded in 24 January 1979. In this study, the nocturnal temperature inversions (radiation inversion and subsidence inversion) are identified by the analysis of Bandar Abbas upper-air station radiosonde data at 00Z from 17 October 2005 to 08 July 2024 and then analyzed. The radiosonde measurements provide high resolution vertical atmospheric temperature which is very appropriate to study the temperature inversions. Temperature inversion detection was done by RAOB application. The analysis includes frequency, depth, and strength of the inversions on a monthly and annual basis. After detecting the radiative inversion layer, first of all the best curve was fitted to the revealed data and then based on the values of 5, 25, 50, 75 and 95% of the fitted curve, the depth and intensity values of radiative inversion. Base on the Delta-Z and Delta-T, the radiation inversion depth and intensity were classified and their annual and monthly occurrence frequencies are analyzed. The very weak, weak, moderate, strong and very strong inversions are characterized by the Delta-T which is less than 1.8, 3.3, 5.2, 8.8 and greater than 8.8 °C respectively. Furthermore, the very shallow, shallow, moderate, deep and very deep inversions are Characterized by the Delta-Z, which is less than 74, 128, 232, 668 and greater than 668 meter respectively.
<strong>Results and Discussion</strong>
The analysis of the nighttime temperature inversions in Bandar Abbas station reveals that at least in half of the summer days (June, July, August, September), radiation inversion was not developed and a uniform monthly frequency distribution was observed. Occurrence of radiation inversion at 85% of the days in October, November, December, January, February and March, was detected. The longer winter nights and the southerly radiation inversion wind of the sea breeze toward the land during the daytime and the northerly wind of the land breeze to the sea at night can provide suitable conditions for creating the radiation inversion of Bandar Abbas. In this station, the frequency of days without subsidence inversion in hot months, is less than in cold months of the year. This condition is due to the establishment of subtropical highs in the region. The frequency of deep and very deep radiative inversion in Bandar Abbas station is higher in the warm months of the year than in other months but the frequency of radiative inversion with moderate depth in the months of January, February, November and December are more than other months. The reason for this difference is the combination of the advection inversion created by the return branch of the sea breeze to land in the warm season with the nighttime radiation inversion. The results of the analysis of radiation inversion intensity showed that the frequency of very strong radiation inversion in the months of November, December, and January is higher than the intense and moderate inversions.The classification of the radiation inversions according to the magnitude of depth (Delta-Z) indicates the prevalence of very shallow (20.5%), shallow (27.5%) and moderate (23.7) inversions in Bandar Abbas. Also, frequency of deep and very deep inversions was estimated 15.9% and 8.5% respectively. The analysis of the frequencies base on the intensity (Delta-T), indicated that the frequency of very weak, weak and moderate radiation inversions in Bandar Abbas is 20.5%, 21.2% and 25.2% respectively. The frequency of strong and very strong inversions was estimated 21.3% and 4.2% respectively. The results showed that the upper levels inversion frequency at Bandar Abbas station was about 83.2% that 11.1% that is of the thermal inversion, 47.9% that is of subsidence inversion and 24.2% that is of the advection inversion.
<strong> </strong>
<strong>Conclusion</strong>
The aim of this work is to analyze and classification characteristics of traditional inversion in Bandar Abbas station. Temperature inversion refers to the increase of air temperature with height along the vertical atmospheric column. For this purpose, the nighttime radiation inversion and subsidence inversion are identified from the analysis of Bandar Abbas upper-air station radiosonde data at 00Z from 17 October 2005 to 08 July 2024 and then analyzed. Detection of temperature inversion was done with RAOB application. The analysis includes frequency, depth, and strength of inversions on a monthly and annual basis. Based on the study results, it is found that the height of radiation inversion in Bandar Abbas has not exceeded 1500 meters in this statistical period. In the months of July and August, the highest frequency of radiation inversion is in the high of 501-700 meters but in the rest of
the months and in the whole period, the highest frequency is estimated in the high of 51-150 meters. Also, In the statistical period of 2005-2024, the maximum height of the radiation inversion ceiling of Bandar Abbas station is 1420 meters in May, 1428 meters in June, and 1413 meters in July. The results in Bandar Abbas station reveals that at least in half of the summer days (June, July, August, September) a radiation inversion was not developed. In addition, at in 85% of the days October, November, December, January, February and March a radiation inversion was detected. In winter the long length of winter nights and the southerly wind of the sea breeze to the land during the day and the northerly wind of the land breeze to the sea at night can provide suitable conditions for creating the radiation inversion in Bandar Abbas. In this station, the frequency of days without subsidence inversion in hot months, is less than in cold months of the year. This condition is due to the establishment of subtropical highs in the region. In addition, the frequency of deep and very deep radiative inversion in Bandar Abbas station is higher in the warm months of the year than in other months but the frequency of radiative inversion with moderate depth in the months of January, February, November and December are more than other months. The reason for this difference is the combination of the advection inversion created by the return branch of the sea breeze to land in the warm season with the nighttime radiation inversion. The results of the analysis of radiation inversion intensity showed that the frequency of very strong radiation inversion in November, December, and January is higher than the strong and moderate inversions.https://esrj.sbu.ac.ir/article_105824_3ab94c19f172ea70af0a67cbfc4cc7f4.pdfShahid Beheshti UniversityResearches in Earth Sciences2008-829916220250522Assessment of the relationship between urbanization of Mashhad metropolis and geomorphic hazards susceptibility in the Middle Kashafroud WatershedAssessment of the relationship between urbanization of Mashhad metropolis and geomorphic hazards susceptibility in the Middle Kashafroud Watershed11213010582710.48308/esrj.2025.105827FAMahboubehKaniDepartment of Geography, Faculty of Literatures & human sciences, Ferdowsi University of Mashhad, Mashhad, Iran0009-0002-8208-3294NedaMohseniDepartment of Geography, Faculty of Literatures & human sciences, Ferdowsi University of Mashhad, Mashhad, Iran0000-0003-0691-9408RezaHosseinzadehDepartment of Geography, Faculty of Literatures & human sciences, Ferdowsi University of Mashhad, Mashhad, Iran0000-0002-8653-5473Journal Article20250313<strong>Introduction</strong>
Urbanization is affected by multiple variables such as geomorphic landform and landscape, population growth, economic growth, and geomorphic hazards. However, during urban planning and development, more emphasis is given to social and economic factors. Usually, the cities or region’s vulnerability to hazards is not properly assessed. Hence, in areas which lie in a rugged landscape, such as alluvial fan, slope area, alluvial plain, and pediment, geomorphic hazards such as landslide, land subsidence, flash flood, and debris flow can occur frequently. This can cause severe damage to human lives and their property. To avoid such scenarios, urban planners, decision-makers, engineers, policymakers should consider not only the physical urban environment but also its susceptibility to natural hazards. The Mashhad is the second largest metropolitan area in Iran with nearly 294 square kilometers. The Mashhad is located on northeast Iran. Mashhad is one of the Iranian metropolitan cities which is located in semi-arid with annual precipitation of 260mm, and mean annual temperature of 14 °C. The Mashhad has experienced a rapid growth in recent decades and has been suffering from geomorphic hazard. Nonetheless, no geomorphological practical analysis has been carried out for Mashhad. Due to its unbalanced development, it has many environmental problems. The Mashhad is highly migratory and suffers severely from informal settlements. Groundwater overexploitation due to population pressure stimulates the occurrence of geomorphic hazard such as land subsidence, and it urgently needs planned development and management of geomorphological structures. In this regard, the multi-hazard approach helps understand how hazards and vulnerabilities are combined over territory and gives a more accurate representation of the complexity of the risks for an area. This study investigated the urbanization impacts of Mashhad Metropolis and Geomorphologic Hazards with Emphasis on the Middle Kashafroud Watershed. In this regard, the physical development of Mashhad during a 20-year period (2003-2023) was first investigated and its development trend was predicted for the next 10 years (2033). Then, a comprehensive analysis of the relationship between the current and future physical development of Mashhad and its effects on the processes of landslides and subsidence has been presented. The results of this research, by improving comprehensive understanding of the environmental challenges, provide a pathway for urban planners and managers to increase urban resilience against these hazards.
<strong>Materials and Methods</strong>
This research was designed in three main steps with the aim of studying and predicting the relationship between the urbanization of Mashhad metropolises and geomorphologic hazards with emphasis on the middle Kashafroud watershed. In the first step, the physical development of Mashhad from 2003 to 2023 was investigated using Landsat satellite images and the maximum likelihood classification algorithm, and a land use map was generated. Then, using the Land Change Modeler (LCM) and Markov chain, the physical development trend of the city was predicted for the ten years (until 2033). In the second step, the landslide susceptibility assessment was evaluated using the weighted linear combination (WLC) method and analytical hierarchy process (AHP). Then, the land subsidence susceptibility assessment was estimated using the radar interferometry technique and Sentinel-1 images. Finally, the relationship between the physical development of Mashhad and changes in the processes related to landslides and land subsidence was analyzed.
<strong> </strong>
<strong>Results and Discussion</strong>
Based on the results of the land use classification map, during the 20-year period, the urbanization has significantly developed. Agricultural land use has been decreasing. Rainfed agricultural land use, developed in the central and eastern parts of the Kashafroud watershed, increased in 2013 and decreased again in 2023. Poor pastures, which is covered the northern basin, significantly decreased in 2013 compared to 2003. Orchards, which are mostly spread along the valleys, especially in the southwest and northern basin, have decreased in recent years. Medium pasture is covered the southwestern areas. This type of land use showed a significant increase in 2013 compared to 2003, but it did not show much change compared to 2023. Other land uses, such as water bodies and fallow lands, have not changed during the 20 years; only fallow lands have slightly increased in 2013. The results showed that the physical development of the Mashhad metropolis is closely related to two geomorphic hazards, landslide and land subsidence. Slopes of the Binalood Mountain and Hazar Masjed Mountain in the southwest and northeast of Mashhad are prone to landslide due to sensitive geological structure and high erodibility of the rocks. Urban expansion towards the highlands and steep areas and along valleys, and the destruction of vegetation, increase the risk of landslide. On the other hand, land subsidence in Mashhad is mainly due to the overexploitation of groundwater resources and subsequently declining groundwater levels. The urban expansion in the southeast and northwest of the Mashhad plain have increased the vulnerability of these areas to land subsidence, so that in some areas the subsidence rate reaches more than 45 cm per year. This phenomenon is a serious threat to infrastructure, structures, and the urban environment.
<strong> </strong>
<strong>Conclusion</strong>
The Mashhad metropolises exhibit the rapid and significant expansion in recent years. This physical expansion has occurred due to population growth, migration, economic and cultural development. However, this expansion has been accompanied by environmental, social, and economic challenges and consequences. A critical factor in managing these challenges is the integration of geomorphological aspects and its principles into urban planning. A comprehensive understanding of how geomorphological processes affect urban areas is crucial for developing effective and sustainable urban planning and management strategies. These solutions are particularly important in dealing with natural hazards, managing risks, and enhancing urban resilience. In the present research, land use changes in the middle Kashafrood watershed were investigated over a 20-year period (2003 to 2023). Then, the changes were predicted until 2033. Residential areas, with a significant increasing trend in the past 20 years, have accounted for the most changes. A significant decrease in the area of agricultural land indicates the impact of the physical expansion of the urban area on decreasing agricultural land. Study of lithological units shows that landslide-prone structures such as the Mozduran, Chaman-Bid, and Upper Red structures, especially in the northern watershed, have a high potential for landslide occurrence. Based on the subsidence results, the highest subsidence values have occurred in the northwestern and the northeastern Mashhad. This is due to the presence of several factors, including groundwater overexploitation and the geological conditions of the region. The northwestern and northeastern areas of Mashhad, which showed the highest subsidence rates, are usually areas where groundwater overexploitation has occurred. These areas include urban and agricultural areas that
require special water resource management. Finally, the present research has investigated the geomorphological impacts on the urban development and the challenges arising from natural hazards such as landslides and subsidence. The expansion of Mashhad is closely related to geomorphological landforms. Accur ate knowledge of these landforms and their impacts on urban development can help to improve the planning and management process. Geomorphological landforms, due to their multifaceted impacts on various factors such as location, urban growth pattern, infrastructure, and hazard management, are considered one of the fundamental aspects of urban planning. Mashhad, as one of the metropolises of Iran, is directly influenced by geomorphological elements such as highlands, slopes, alluvial fans, streams, riverbeds, and topography. The Binaloud Mountain in the south and Hazar-Masjed in the northeast of Mashhad, as natural barriers, have limited the physical expansion of the city. Construction on these slopes faces problems such as landslides and soil erosion. In contrast, plain surfaces with alluvial soils in the southern and northwestern parts have provided a favorable condition for urban and agricultural development. However, groundwater overexploitation in these areas has caused the occurrence of land subsidence, which is a serious challenge for sustainable development. Alluvial fan areas, due to their suitable soil permeability, have been employed as suitable conditions for the urban expansion, especially in the northwest and along the Binaloud pediment. The relationship between the expansion of Mashhad and the occurrence of landslide and land subsidence is an important challenge that requires serious attention. The physical expansion of Mashhad and its surroundings, especially in the northwest of the Mashhad plain, has increased the need for water resources. Expansion in steep areas, construction in steep and unstable areas without considering geological characteristics can lead to landslides, which cause great loss of life and property. The Hazar-Masjed and Binaloud Mountains present distinct geomorphological and lithological characteristics influencing landslide susceptibility. The western Binaloud Mountains, dominated by resistant rock units like the Mashhad phyllite, exhibit a moderate landslide potential. In general, lack of proper planning for urbanization management, human manipulation, destabilization of slopes, deforestation, and geological and lithological structures are among the causes of landslides in the Mashhad plain. Overall, a detailed study of the geomorphology of a region not only helps to better understand the natural dynamics and their effects on urban development, but can also lead to the development of efficient policies for urban management and reducing the risk of natural hazard. The results of this research, by improving comprehensive understanding of the environmental challenges, provide a pathway for urban planners and managers to increase urban resilience against these hazards.<strong>Introduction</strong>
Urbanization is affected by multiple variables such as geomorphic landform and landscape, population growth, economic growth, and geomorphic hazards. However, during urban planning and development, more emphasis is given to social and economic factors. Usually, the cities or region’s vulnerability to hazards is not properly assessed. Hence, in areas which lie in a rugged landscape, such as alluvial fan, slope area, alluvial plain, and pediment, geomorphic hazards such as landslide, land subsidence, flash flood, and debris flow can occur frequently. This can cause severe damage to human lives and their property. To avoid such scenarios, urban planners, decision-makers, engineers, policymakers should consider not only the physical urban environment but also its susceptibility to natural hazards. The Mashhad is the second largest metropolitan area in Iran with nearly 294 square kilometers. The Mashhad is located on northeast Iran. Mashhad is one of the Iranian metropolitan cities which is located in semi-arid with annual precipitation of 260mm, and mean annual temperature of 14 °C. The Mashhad has experienced a rapid growth in recent decades and has been suffering from geomorphic hazard. Nonetheless, no geomorphological practical analysis has been carried out for Mashhad. Due to its unbalanced development, it has many environmental problems. The Mashhad is highly migratory and suffers severely from informal settlements. Groundwater overexploitation due to population pressure stimulates the occurrence of geomorphic hazard such as land subsidence, and it urgently needs planned development and management of geomorphological structures. In this regard, the multi-hazard approach helps understand how hazards and vulnerabilities are combined over territory and gives a more accurate representation of the complexity of the risks for an area. This study investigated the urbanization impacts of Mashhad Metropolis and Geomorphologic Hazards with Emphasis on the Middle Kashafroud Watershed. In this regard, the physical development of Mashhad during a 20-year period (2003-2023) was first investigated and its development trend was predicted for the next 10 years (2033). Then, a comprehensive analysis of the relationship between the current and future physical development of Mashhad and its effects on the processes of landslides and subsidence has been presented. The results of this research, by improving comprehensive understanding of the environmental challenges, provide a pathway for urban planners and managers to increase urban resilience against these hazards.
<strong>Materials and Methods</strong>
This research was designed in three main steps with the aim of studying and predicting the relationship between the urbanization of Mashhad metropolises and geomorphologic hazards with emphasis on the middle Kashafroud watershed. In the first step, the physical development of Mashhad from 2003 to 2023 was investigated using Landsat satellite images and the maximum likelihood classification algorithm, and a land use map was generated. Then, using the Land Change Modeler (LCM) and Markov chain, the physical development trend of the city was predicted for the ten years (until 2033). In the second step, the landslide susceptibility assessment was evaluated using the weighted linear combination (WLC) method and analytical hierarchy process (AHP). Then, the land subsidence susceptibility assessment was estimated using the radar interferometry technique and Sentinel-1 images. Finally, the relationship between the physical development of Mashhad and changes in the processes related to landslides and land subsidence was analyzed.
<strong> </strong>
<strong>Results and Discussion</strong>
Based on the results of the land use classification map, during the 20-year period, the urbanization has significantly developed. Agricultural land use has been decreasing. Rainfed agricultural land use, developed in the central and eastern parts of the Kashafroud watershed, increased in 2013 and decreased again in 2023. Poor pastures, which is covered the northern basin, significantly decreased in 2013 compared to 2003. Orchards, which are mostly spread along the valleys, especially in the southwest and northern basin, have decreased in recent years. Medium pasture is covered the southwestern areas. This type of land use showed a significant increase in 2013 compared to 2003, but it did not show much change compared to 2023. Other land uses, such as water bodies and fallow lands, have not changed during the 20 years; only fallow lands have slightly increased in 2013. The results showed that the physical development of the Mashhad metropolis is closely related to two geomorphic hazards, landslide and land subsidence. Slopes of the Binalood Mountain and Hazar Masjed Mountain in the southwest and northeast of Mashhad are prone to landslide due to sensitive geological structure and high erodibility of the rocks. Urban expansion towards the highlands and steep areas and along valleys, and the destruction of vegetation, increase the risk of landslide. On the other hand, land subsidence in Mashhad is mainly due to the overexploitation of groundwater resources and subsequently declining groundwater levels. The urban expansion in the southeast and northwest of the Mashhad plain have increased the vulnerability of these areas to land subsidence, so that in some areas the subsidence rate reaches more than 45 cm per year. This phenomenon is a serious threat to infrastructure, structures, and the urban environment.
<strong> </strong>
<strong>Conclusion</strong>
The Mashhad metropolises exhibit the rapid and significant expansion in recent years. This physical expansion has occurred due to population growth, migration, economic and cultural development. However, this expansion has been accompanied by environmental, social, and economic challenges and consequences. A critical factor in managing these challenges is the integration of geomorphological aspects and its principles into urban planning. A comprehensive understanding of how geomorphological processes affect urban areas is crucial for developing effective and sustainable urban planning and management strategies. These solutions are particularly important in dealing with natural hazards, managing risks, and enhancing urban resilience. In the present research, land use changes in the middle Kashafrood watershed were investigated over a 20-year period (2003 to 2023). Then, the changes were predicted until 2033. Residential areas, with a significant increasing trend in the past 20 years, have accounted for the most changes. A significant decrease in the area of agricultural land indicates the impact of the physical expansion of the urban area on decreasing agricultural land. Study of lithological units shows that landslide-prone structures such as the Mozduran, Chaman-Bid, and Upper Red structures, especially in the northern watershed, have a high potential for landslide occurrence. Based on the subsidence results, the highest subsidence values have occurred in the northwestern and the northeastern Mashhad. This is due to the presence of several factors, including groundwater overexploitation and the geological conditions of the region. The northwestern and northeastern areas of Mashhad, which showed the highest subsidence rates, are usually areas where groundwater overexploitation has occurred. These areas include urban and agricultural areas that
require special water resource management. Finally, the present research has investigated the geomorphological impacts on the urban development and the challenges arising from natural hazards such as landslides and subsidence. The expansion of Mashhad is closely related to geomorphological landforms. Accur ate knowledge of these landforms and their impacts on urban development can help to improve the planning and management process. Geomorphological landforms, due to their multifaceted impacts on various factors such as location, urban growth pattern, infrastructure, and hazard management, are considered one of the fundamental aspects of urban planning. Mashhad, as one of the metropolises of Iran, is directly influenced by geomorphological elements such as highlands, slopes, alluvial fans, streams, riverbeds, and topography. The Binaloud Mountain in the south and Hazar-Masjed in the northeast of Mashhad, as natural barriers, have limited the physical expansion of the city. Construction on these slopes faces problems such as landslides and soil erosion. In contrast, plain surfaces with alluvial soils in the southern and northwestern parts have provided a favorable condition for urban and agricultural development. However, groundwater overexploitation in these areas has caused the occurrence of land subsidence, which is a serious challenge for sustainable development. Alluvial fan areas, due to their suitable soil permeability, have been employed as suitable conditions for the urban expansion, especially in the northwest and along the Binaloud pediment. The relationship between the expansion of Mashhad and the occurrence of landslide and land subsidence is an important challenge that requires serious attention. The physical expansion of Mashhad and its surroundings, especially in the northwest of the Mashhad plain, has increased the need for water resources. Expansion in steep areas, construction in steep and unstable areas without considering geological characteristics can lead to landslides, which cause great loss of life and property. The Hazar-Masjed and Binaloud Mountains present distinct geomorphological and lithological characteristics influencing landslide susceptibility. The western Binaloud Mountains, dominated by resistant rock units like the Mashhad phyllite, exhibit a moderate landslide potential. In general, lack of proper planning for urbanization management, human manipulation, destabilization of slopes, deforestation, and geological and lithological structures are among the causes of landslides in the Mashhad plain. Overall, a detailed study of the geomorphology of a region not only helps to better understand the natural dynamics and their effects on urban development, but can also lead to the development of efficient policies for urban management and reducing the risk of natural hazard. The results of this research, by improving comprehensive understanding of the environmental challenges, provide a pathway for urban planners and managers to increase urban resilience against these hazards.https://esrj.sbu.ac.ir/article_105827_a81cad6cb8e49065dd6a3d16c3740f80.pdfShahid Beheshti UniversityResearches in Earth Sciences2008-829916220250522Analysis of the positioning of pressure systems in the Afria Zone during the last fifty years of dust days in IranAnalysis of the positioning of pressure systems in the Afria Zone during the last fifty years of dust days in Iran13114410520710.48308/esrj.2024.236608.1231FAGholamrezaBaratiDepartment of Physical Geography, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran0000-0001-9023-8239MohammadMoradiResearch Institute of Meteorology and Atmospheric Science (RIMAS), Tehran, Iran0000-0002-5356-8578MersadJafari GharehchiDepartment of Physical Geography, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran0009-0004-1889-5524Journal Article20240909<strong>Introduction</strong>
Pressure systems, including low and high pressures, are among the most important factors in shaping the general circulation of the atmosphere on Earth. These systems influence seasonal air circulation and wind patterns, and depending on the conditions of the water and land areas over which they blow, they determine the type of movable particles, especially floating particles (in this research, dust).
<strong>Study area</strong>
The land of research for this study with an environmental approach, encompasses the country of Iran in the southwest of Asia, covering an area of 1.65 million square kilometers. With a synoptic approach, it includes a region extending from the equator to 70 degrees north latitude and from 20 degrees west to 100 degrees east longitude.
<strong> </strong>
<strong>Materials and Methods</strong>
In the current research, the hourly codes "06," representing the general concept of "visibility in meters," were collected from the dust code set for 38 cities in Iran over half a century (1970 to 2020) and related to the local time of 15:00 from the National Meteorological Organization. In this study, a dusty day was defined as a day with at least one hourly dust report. The selection of meteorological stations was conducted in a way that covers all over Iran. By arranging visibility values in daily tables and obtaining the frequency of stations with dust (abbreviated as "EDR"), 612 charts of the fluctuations in EDR frequency (one chart for each month) were drawn, and by applying two identifiers of "dust events based on visibility distance for at least during 3 consecutive days" and "dust reports from at least two adjacent stations," a total of 561 dust waves were identified. Therefore, each dust wave has three distinct elements, which include an increasing amplitude, a peak day, and then a decreasing amplitude of dust frequency. The aim of the continuous selection method of days for retrieving dust waves was to test the hypothesis of the impact of pressure systems on the arrangement and duration of the elements mentioned above in the form of positioning patterns of these systems. In the synoptic section, the loading of daily air-maps at the level of 1000 hPa from NCEP/ENCAR and the design of positioning patterns of pressure centers, both low and high pressure, during peak dust days was conducted in two time frames: the first time "distinguished by warm and cold periods of the year" and the second time "distinguished by two 25-year periods." For this purpose, the months of "June, July, August, and September" were considered representative of the warm period of the year, while the months of "December, January, February, and March" were considered representative of the cold period of the year.
<strong>Results and Discussion</strong>
The initial results showed that over the past half-century, among the 38 selected cities in Iran, three cities -Bandar Abbas, Bandar Genaveh, and Dezful—have been distinctly the dustiest in Iran. It was also determined that out of 561 dust wave events recorded in Iran, 189 occurred during the warm and 207 during the cold season. The trend in the frequency of dust waves indicates an increase in this dust hazard over the past half-century, especially during the warm season. In the synoptic section, the results indicated the northward advance of subtropical high-pressure centers over the past 25 years, particularly during the cold season. As a result, the desert belt in this part of the Earth has transformed into a buffer zone between generally low-pressure systems in the south and generally high-pressure systems in the north. This condition is also observed, albeit with less intensity, during the warm season. In this study, this supercontinent devoid of pressure systems during peak storm days of the cold season, extending from the deserts of Africa to the deserts of Asia, was referred to as "Afria" to indicate its orbital direction over the desert lands of these two continents, including the Sahara in Africa and the deserts of Hijaz, Iran, Turan, Tarim and Gobi in Asia. The deserts of this zone are the source of air currents or well-organized winds from the Hadley cell.
<strong> </strong>
<strong>Conclusion</strong>
Comparison of the northerly positioning of subtropical high-pressure foci suggested the expansion of the Hadley cell in three zones of "African Desert", "Southern Mediterranean Waters" and "Hejaz". If it is determined in the future and with sufficient data that this expansion has also included the land of Iran, we should be more concerned than ever about the arrival of dust from the dusty deserts of Turkmenistan (Central Asia) to Sistan and Baloochestan in the east and southeast of Iran, and as a result, days darker than dust.<strong>Introduction</strong>
Pressure systems, including low and high pressures, are among the most important factors in shaping the general circulation of the atmosphere on Earth. These systems influence seasonal air circulation and wind patterns, and depending on the conditions of the water and land areas over which they blow, they determine the type of movable particles, especially floating particles (in this research, dust).
<strong>Study area</strong>
The land of research for this study with an environmental approach, encompasses the country of Iran in the southwest of Asia, covering an area of 1.65 million square kilometers. With a synoptic approach, it includes a region extending from the equator to 70 degrees north latitude and from 20 degrees west to 100 degrees east longitude.
<strong> </strong>
<strong>Materials and Methods</strong>
In the current research, the hourly codes "06," representing the general concept of "visibility in meters," were collected from the dust code set for 38 cities in Iran over half a century (1970 to 2020) and related to the local time of 15:00 from the National Meteorological Organization. In this study, a dusty day was defined as a day with at least one hourly dust report. The selection of meteorological stations was conducted in a way that covers all over Iran. By arranging visibility values in daily tables and obtaining the frequency of stations with dust (abbreviated as "EDR"), 612 charts of the fluctuations in EDR frequency (one chart for each month) were drawn, and by applying two identifiers of "dust events based on visibility distance for at least during 3 consecutive days" and "dust reports from at least two adjacent stations," a total of 561 dust waves were identified. Therefore, each dust wave has three distinct elements, which include an increasing amplitude, a peak day, and then a decreasing amplitude of dust frequency. The aim of the continuous selection method of days for retrieving dust waves was to test the hypothesis of the impact of pressure systems on the arrangement and duration of the elements mentioned above in the form of positioning patterns of these systems. In the synoptic section, the loading of daily air-maps at the level of 1000 hPa from NCEP/ENCAR and the design of positioning patterns of pressure centers, both low and high pressure, during peak dust days was conducted in two time frames: the first time "distinguished by warm and cold periods of the year" and the second time "distinguished by two 25-year periods." For this purpose, the months of "June, July, August, and September" were considered representative of the warm period of the year, while the months of "December, January, February, and March" were considered representative of the cold period of the year.
<strong>Results and Discussion</strong>
The initial results showed that over the past half-century, among the 38 selected cities in Iran, three cities -Bandar Abbas, Bandar Genaveh, and Dezful—have been distinctly the dustiest in Iran. It was also determined that out of 561 dust wave events recorded in Iran, 189 occurred during the warm and 207 during the cold season. The trend in the frequency of dust waves indicates an increase in this dust hazard over the past half-century, especially during the warm season. In the synoptic section, the results indicated the northward advance of subtropical high-pressure centers over the past 25 years, particularly during the cold season. As a result, the desert belt in this part of the Earth has transformed into a buffer zone between generally low-pressure systems in the south and generally high-pressure systems in the north. This condition is also observed, albeit with less intensity, during the warm season. In this study, this supercontinent devoid of pressure systems during peak storm days of the cold season, extending from the deserts of Africa to the deserts of Asia, was referred to as "Afria" to indicate its orbital direction over the desert lands of these two continents, including the Sahara in Africa and the deserts of Hijaz, Iran, Turan, Tarim and Gobi in Asia. The deserts of this zone are the source of air currents or well-organized winds from the Hadley cell.
<strong> </strong>
<strong>Conclusion</strong>
Comparison of the northerly positioning of subtropical high-pressure foci suggested the expansion of the Hadley cell in three zones of "African Desert", "Southern Mediterranean Waters" and "Hejaz". If it is determined in the future and with sufficient data that this expansion has also included the land of Iran, we should be more concerned than ever about the arrival of dust from the dusty deserts of Turkmenistan (Central Asia) to Sistan and Baloochestan in the east and southeast of Iran, and as a result, days darker than dust.https://esrj.sbu.ac.ir/article_105207_119a95c83d0fd4a58ce67f46a1c0b0ab.pdfShahid Beheshti UniversityResearches in Earth Sciences2008-829916220250522Evaluating the effect of geomorphology in the physicochemical properties of soils of alluvial fan surface (Case study: alluvial fan of northwest of Amiriyeh, Damghan)Evaluating the effect of geomorphology in the physicochemical properties of soils of alluvial fan surface (Case study: alluvial fan of northwest of Amiriyeh, Damghan)14516610582510.48308/esrj.2025.238331.1248FAShahramBahramiDepartment of Physical Geography, Faculty of Earh Sciences, Shahid Beheshti University, Tehran, Iran0000-0003-1336-5204Mohammad MehdiHoseinzadehDepartment of Physical Geography, Faculty of Earh Sciences, Shahid Beheshti University, Tehran, Iran0000-0002-4961-0657PoonehBabaeiDepartment of Physical Geography, Faculty of Earh Sciences, Shahid Beheshti University, Tehran, IranJournal Article20250110<strong>Introduction</strong>
Soil is one of the most important agents of production and profoundly influences the human life. Nowadays, soil erosion is one of the main environmental problems that is regarded as threat to natural resources, agriculture, and environment (Rahman et al, 2009). Therefore, it is very important to evaluate the physicochemical characteristics of soils in order to prevent its erosion. Alluvial fans are suitable locations for settlements (Waters and Field, 1986; Maghsoudi et al, 2014), the groundwater recharge (Bull, 1977; Houston, 2002; Blainey and Pelletier, 2008), the exploitation of aggregates (Fookes et al, 2007; Bahrami et al, 2015), soil formation (Norton et al, 2007; Bahrami and Ghahraman, 2019), agriculture (Field, 1992; Rahaman, 2016) and other human activities. Development of alluvial fans are affected by different factors such as tectonic activity, climate, base level change, geological and morphometric properties of catchments (Beaumont, 1972; Waters and Field, 1986; Blair and Mcpherson, 1998; Crosa et al, 2004; Arzani, 2005; Bahrami, 2013, Arzani and Jones, 2018; Goswami, 2018; Özpolat et al, 2022; Peng e al, 2024; Ghahraman and Nagy, 2024). Alluvial fans as one of the most important depositional landforms of arid and semi-arid regions have considerable diversity in terms of evolution and morphometry. Every alluvial fan may be composed of surfaces with different ages such as young, old and relict surfaces. Difference in relative age of fan surfaces can result in the variation of geomorphological processes and morphometry, and hence in the variation of soil properties and development. The aim of this research is to evaluate quantitative properties of soil in different surfaces, positions, and landforms of alluvial fan located in the northwest of Amiriyeh, Damghan. The study area is located in the southern part of Alborz structural zone, and northern part of Central Iran structural zone. Damghan Playa is located in the southern part of the study area.
<strong>Materials and Methods</strong>
First, the borders of relict, old and young surfaces of studied alluvial fan were identified based on weathering rate, fan surface morphology, drainage pattern, color/tone on satellite images (Field, 1994; Bahrami and Bahrami, 2011) and field works. Owing to the highest concentration of vegetation root and organic carbon in the top 30 cm of soils, in this research, 24 soil samples from depths of 0–30 cm were gathered from alluvial fan surface. Samples were collected from positions (apex, toe), surfaces (relict, old and young), and landforms of young surface (bar and swale), as well as landforms of relict and old surface (interfluve and channel). The soil sampling squares at toes and apexes of different surfaces of fan were selected randomly.
The selective sampling method was used to gather soil samples from landforms (interfluve and channel on
the relict and old surfaces, and bar & swale on the young surface). From each surface (old, relict and young), 8 soil samples were gathered (4 from apex and 4 from toe). On each position (apex and toe) of the old and relict surfaces, two soil samples were gathered from interfluves and two from channels.
Also, on each position of the young surface, two soil samples were gathered from swale and two from bar landforms. The soil samples were transformed to the laboratory and then clay%, silt%, sand%, organic carbon, Ph, and soil hydraulic conductivity (K) were measured. The soil texture was calculated by the hydrometer method (Kroetsch and Wang, 2008). The soil organic carbon (OC) was measured by Walkley-Black titration method (Walkley and Black, 1934). The hydraulic conductivity (K) of soil samples was calculated based on the Saxton et al. (1986) method:
Eq. 1:
where K is unsaturated hydraulic conductivity (m/ s) and θ is moisture content (m3/m3) as indicated by the following equation 2:
Eq. 2:
To compare the means of soil variables in alluvial fan positions (apex and toe), landforms of old and relict surfaces (interfluves and channels), and landforms of young surface (bars and swales), the independent sample t-tests were calculated. To compare the means of soil parameters in alluvial fan surfaces (relict, old and young) the ANOVA test was used.
<strong> </strong>
<strong>Results and Discussion</strong>
The studied alluvial fan is composed of three surfaces including relict, old and young surfaces, each having distinct geomorphological features. The relict and old surfaces are characterized by dendritic drainage pattern. Nevertheless, channels on the old surface have lower depth compared to channels on the relict surface, implying lower erosion and relative age of old surface than relict one. Drainage pattern on the young surface is braided. The young surface of alluvial fan is characterized by relatively flat morphology, whereas the relict and old ones have crenulated and entrenched morphology. Field observation revealed that the young surface deposits lack desert varnish and weathering marks, whereas deposits on the relict and old surfaces are exposed to weathering. Results show that sand% on the studied alluvial fan surface varies from 36% (sample 12 on the toe of relict surface) to 96% (sample 11 on the toe of relict surface). The maximum value of Ph (9.27) corresponds to sample 8 on the toe of young surface, and the lowest Ph (7) belongs to sample 17 on the apex of relict surface. The value of soil organic carbon is lower than 1% in all samples, ranging from 0.07% (sample 17 on the apex of old surface) to 0.74% (sample 20 on the apex of relict surface). The value of soil hydraulic conductivity (K) varies from 1.22 (sample 15 on the apex of relict surface) to 13.71 cm/h (sample 11 on the toe of relict surface). Data show that soil texture is coarser in fan apex compared to its toe. This is due to decrease in slope gradient and also to flow diversion, and hence decrease in flow velocity that cause the coarse sediments to deposit in apex and the fine sediments to deposit in the toe of alluvial fan. In spite of the coarser texture soils of apex, the mean values of soil hydraulic conductivity do not have meaningful difference at apex and toe of alluvial fan. Although previous studies have suggested that soil organic carbon in depositional landforms is often higher compared to erosional landforms in upstream areas (Vanden Bygaart et al, 2015; Xiao et al, 2015), results of this study revealed that soil organic carbon is lower at fan toe than fan apex. The lower value of organic carbon in alluvial fan toe can be attributed to the higher moisture and hence increased microbial activity, facilitating soil organic carbon decomposition and consequently its loss (Mohseni et al, 2019). Results demonstrate that channels formed on the relict and old surfaces have remarkably coarser soils compared to interfluves. The soil texture is also coarser in swales than bars of young surface. The mean value of Ph is higher at toe than apex implying that soils of fan toe is more alkaline than its apex. The more alkaline soils of alluvial fan toe can be attributed to the finer textured soils and hence their lower leching. The higher value of soil organic carbon in channels compared to the interfluves of old and relict surfaces can be attributed to the denser vegetation of channels. Results of ANOVA test show that the means of soil hydraulic conductivity do not have significant differences in different surfaces (relict, old, and young). The values of soil hydraulic conductivity at the apex and toe of alluvial fan are similar and do not show considerable difference. Evaluation of t-test to compare means of hydraulic conductivity revealed that the means of this parameter in bars and swales of young surface have
significant differences, implying the micro-landforms of bars and swales have fundamental impact in the variation of hydraulic conductivity. Based on t-test values, means of soil hydraulic conductivity also have significant differences in the interfluves and channels of relict and old surfaces, showing that the micro-landforms of interfluves and channels have also had strong control in the variation of soil hydraulic conductivity. Evaluation of the relation between parameters (Pearson's correlation coefficient) reveals that there is meaningful negative correlation between Ph and elevation. The soil organic carbon is strongly positively correlated with elevation. The soil hydraulic conductivity has a meaningful positive correlation with sand%, whereas it has meaningful negative correlations with clay% and silt%.
<strong> </strong>
<strong>Conclusion</strong>
The study area alluvial fan is located in the in the northwest of Amiriyeh, and is composed of three surfaces of relict, old and young, where morphology and geomorphological processes are different on each surface. Different geomorphological processes and landforms in different surfaces and also in different positions (apex and toe) have resulted in the spatial variation of physicochemical characteristics of soils of alluvial fan. Results imply that soil hydraulic conductivity is lower in the old surface compared to the relict and young surfaces. The lower soil hydraulic conductivity of old surface can be associated with relative stability, weathering and increasing clay% of soils of old surface, resulting in reducing soils permeability and hydraulic conductivity. The values of soil texture and hydraulic conductivity in landforms (interfluves compared to channels, and bars compared to swales) have meaningful statistical differences. This implies the mentioned landforms have fundamental effect in the variation of soil hydraulic conductivity of alluvial fan. Regarding the fact that improved understanding of physicochemical properties of soils has important role in the management and conservation of soil and vegetation, it is suggested that planners and managers consider differences in quantitate properties of soils in different landforms, positions, and surfaces of alluvial fans.<strong>Introduction</strong>
Soil is one of the most important agents of production and profoundly influences the human life. Nowadays, soil erosion is one of the main environmental problems that is regarded as threat to natural resources, agriculture, and environment (Rahman et al, 2009). Therefore, it is very important to evaluate the physicochemical characteristics of soils in order to prevent its erosion. Alluvial fans are suitable locations for settlements (Waters and Field, 1986; Maghsoudi et al, 2014), the groundwater recharge (Bull, 1977; Houston, 2002; Blainey and Pelletier, 2008), the exploitation of aggregates (Fookes et al, 2007; Bahrami et al, 2015), soil formation (Norton et al, 2007; Bahrami and Ghahraman, 2019), agriculture (Field, 1992; Rahaman, 2016) and other human activities. Development of alluvial fans are affected by different factors such as tectonic activity, climate, base level change, geological and morphometric properties of catchments (Beaumont, 1972; Waters and Field, 1986; Blair and Mcpherson, 1998; Crosa et al, 2004; Arzani, 2005; Bahrami, 2013, Arzani and Jones, 2018; Goswami, 2018; Özpolat et al, 2022; Peng e al, 2024; Ghahraman and Nagy, 2024). Alluvial fans as one of the most important depositional landforms of arid and semi-arid regions have considerable diversity in terms of evolution and morphometry. Every alluvial fan may be composed of surfaces with different ages such as young, old and relict surfaces. Difference in relative age of fan surfaces can result in the variation of geomorphological processes and morphometry, and hence in the variation of soil properties and development. The aim of this research is to evaluate quantitative properties of soil in different surfaces, positions, and landforms of alluvial fan located in the northwest of Amiriyeh, Damghan. The study area is located in the southern part of Alborz structural zone, and northern part of Central Iran structural zone. Damghan Playa is located in the southern part of the study area.
<strong>Materials and Methods</strong>
First, the borders of relict, old and young surfaces of studied alluvial fan were identified based on weathering rate, fan surface morphology, drainage pattern, color/tone on satellite images (Field, 1994; Bahrami and Bahrami, 2011) and field works. Owing to the highest concentration of vegetation root and organic carbon in the top 30 cm of soils, in this research, 24 soil samples from depths of 0–30 cm were gathered from alluvial fan surface. Samples were collected from positions (apex, toe), surfaces (relict, old and young), and landforms of young surface (bar and swale), as well as landforms of relict and old surface (interfluve and channel). The soil sampling squares at toes and apexes of different surfaces of fan were selected randomly.
The selective sampling method was used to gather soil samples from landforms (interfluve and channel on
the relict and old surfaces, and bar & swale on the young surface). From each surface (old, relict and young), 8 soil samples were gathered (4 from apex and 4 from toe). On each position (apex and toe) of the old and relict surfaces, two soil samples were gathered from interfluves and two from channels.
Also, on each position of the young surface, two soil samples were gathered from swale and two from bar landforms. The soil samples were transformed to the laboratory and then clay%, silt%, sand%, organic carbon, Ph, and soil hydraulic conductivity (K) were measured. The soil texture was calculated by the hydrometer method (Kroetsch and Wang, 2008). The soil organic carbon (OC) was measured by Walkley-Black titration method (Walkley and Black, 1934). The hydraulic conductivity (K) of soil samples was calculated based on the Saxton et al. (1986) method:
Eq. 1:
where K is unsaturated hydraulic conductivity (m/ s) and θ is moisture content (m3/m3) as indicated by the following equation 2:
Eq. 2:
To compare the means of soil variables in alluvial fan positions (apex and toe), landforms of old and relict surfaces (interfluves and channels), and landforms of young surface (bars and swales), the independent sample t-tests were calculated. To compare the means of soil parameters in alluvial fan surfaces (relict, old and young) the ANOVA test was used.
<strong> </strong>
<strong>Results and Discussion</strong>
The studied alluvial fan is composed of three surfaces including relict, old and young surfaces, each having distinct geomorphological features. The relict and old surfaces are characterized by dendritic drainage pattern. Nevertheless, channels on the old surface have lower depth compared to channels on the relict surface, implying lower erosion and relative age of old surface than relict one. Drainage pattern on the young surface is braided. The young surface of alluvial fan is characterized by relatively flat morphology, whereas the relict and old ones have crenulated and entrenched morphology. Field observation revealed that the young surface deposits lack desert varnish and weathering marks, whereas deposits on the relict and old surfaces are exposed to weathering. Results show that sand% on the studied alluvial fan surface varies from 36% (sample 12 on the toe of relict surface) to 96% (sample 11 on the toe of relict surface). The maximum value of Ph (9.27) corresponds to sample 8 on the toe of young surface, and the lowest Ph (7) belongs to sample 17 on the apex of relict surface. The value of soil organic carbon is lower than 1% in all samples, ranging from 0.07% (sample 17 on the apex of old surface) to 0.74% (sample 20 on the apex of relict surface). The value of soil hydraulic conductivity (K) varies from 1.22 (sample 15 on the apex of relict surface) to 13.71 cm/h (sample 11 on the toe of relict surface). Data show that soil texture is coarser in fan apex compared to its toe. This is due to decrease in slope gradient and also to flow diversion, and hence decrease in flow velocity that cause the coarse sediments to deposit in apex and the fine sediments to deposit in the toe of alluvial fan. In spite of the coarser texture soils of apex, the mean values of soil hydraulic conductivity do not have meaningful difference at apex and toe of alluvial fan. Although previous studies have suggested that soil organic carbon in depositional landforms is often higher compared to erosional landforms in upstream areas (Vanden Bygaart et al, 2015; Xiao et al, 2015), results of this study revealed that soil organic carbon is lower at fan toe than fan apex. The lower value of organic carbon in alluvial fan toe can be attributed to the higher moisture and hence increased microbial activity, facilitating soil organic carbon decomposition and consequently its loss (Mohseni et al, 2019). Results demonstrate that channels formed on the relict and old surfaces have remarkably coarser soils compared to interfluves. The soil texture is also coarser in swales than bars of young surface. The mean value of Ph is higher at toe than apex implying that soils of fan toe is more alkaline than its apex. The more alkaline soils of alluvial fan toe can be attributed to the finer textured soils and hence their lower leching. The higher value of soil organic carbon in channels compared to the interfluves of old and relict surfaces can be attributed to the denser vegetation of channels. Results of ANOVA test show that the means of soil hydraulic conductivity do not have significant differences in different surfaces (relict, old, and young). The values of soil hydraulic conductivity at the apex and toe of alluvial fan are similar and do not show considerable difference. Evaluation of t-test to compare means of hydraulic conductivity revealed that the means of this parameter in bars and swales of young surface have
significant differences, implying the micro-landforms of bars and swales have fundamental impact in the variation of hydraulic conductivity. Based on t-test values, means of soil hydraulic conductivity also have significant differences in the interfluves and channels of relict and old surfaces, showing that the micro-landforms of interfluves and channels have also had strong control in the variation of soil hydraulic conductivity. Evaluation of the relation between parameters (Pearson's correlation coefficient) reveals that there is meaningful negative correlation between Ph and elevation. The soil organic carbon is strongly positively correlated with elevation. The soil hydraulic conductivity has a meaningful positive correlation with sand%, whereas it has meaningful negative correlations with clay% and silt%.
<strong> </strong>
<strong>Conclusion</strong>
The study area alluvial fan is located in the in the northwest of Amiriyeh, and is composed of three surfaces of relict, old and young, where morphology and geomorphological processes are different on each surface. Different geomorphological processes and landforms in different surfaces and also in different positions (apex and toe) have resulted in the spatial variation of physicochemical characteristics of soils of alluvial fan. Results imply that soil hydraulic conductivity is lower in the old surface compared to the relict and young surfaces. The lower soil hydraulic conductivity of old surface can be associated with relative stability, weathering and increasing clay% of soils of old surface, resulting in reducing soils permeability and hydraulic conductivity. The values of soil texture and hydraulic conductivity in landforms (interfluves compared to channels, and bars compared to swales) have meaningful statistical differences. This implies the mentioned landforms have fundamental effect in the variation of soil hydraulic conductivity of alluvial fan. Regarding the fact that improved understanding of physicochemical properties of soils has important role in the management and conservation of soil and vegetation, it is suggested that planners and managers consider differences in quantitate properties of soils in different landforms, positions, and surfaces of alluvial fans.https://esrj.sbu.ac.ir/article_105825_e0ca53932b4768ae7422a4cc1c3b118e.pdfShahid Beheshti UniversityResearches in Earth Sciences2008-829916220250522Spatial-social pattern of Tehran's protests in autumn 2022Spatial-social pattern of Tehran's protests in autumn 202216718410582910.48308/esrj.2025.238349.1250FAJavadEtaatDepartment of political science, Faculty of Economics and Political Science, Shahid Beheshti University, Tehran, Iran0000-0002-5827-9820AliakbarDabiriDepartment of political science, Faculty of Economics and Political Science, Shahid Beheshti University, Tehran, IranJournal Article20250117<strong>Introduction</strong>
As the political hub of Iran, Tehran has witnessed several waves of protest and social protests over the past four decades, rooted in diverse political, economic, and cultural contexts and involving various socio-economic classes. The most recent protests and protest occurred in the autumn of 2022. Following the death of a 22-year-old woman in the custody of Tehran’s morality police during the final days of summer 2022, a wave of protest erupted in Tehran and other Iranian cities, lasting for several weeks. These incidents differed significantly from the spatial-temporal patterns and protest methods observed in Tehran’s previous decades of protest. From a socio-spatial perspective, these events can be regarded as a new form of protest and social protest.This study aims to analyze the distribution, intensification, and spread of the 2022 protest in Tehran using the theory of spatial diffusion in geography, identifying the spatial patterns of these incidents. According to this theory, phenomena spread across geographical areas through several mechanisms, including hierarchical diffusion, contagious diffusion, reinforcement diffusion, and spatial redistribution. The primary goal of this article is to identify the spatial diffusion patterns and spread of protest across Tehran using this framework.Additionally, the authors of this article seek to analyze the organization and direction of protests and protest through the lens of collective action theory. In this approach, neighborhoods and local spaces provide the framework and conditions necessary for collective action, including shared interests, organization, mobilization, and opportunities.The central research question of this study concerns the socio-spatial patterns of the autumn 2022 protest in Tehran and the role of neighborhoods as geographical and social units in these incidents. The preliminary response and hypothesis proposed are that these protests exhibited spatial-temporal patterns distinct from those of previous years, with critics and opponents employing different tools and methods.
<strong> </strong>
<strong>Materials and Methods</strong>
This study is applied in its objective and descriptive-analytical in nature, employing a mixed-methods approach with quantitative (Spatial Statistics Tools) and qualitative (field observation) components. The study area encompasses the city of Tehran and its neighborhoods.Data collection was divided into two parts: library/documentary and field methods. In the library section, due to the lack of an independent and reliable source publishing information on the protest, the researchers relied on data and reports from social media, international news agencies, and online platforms. To verify this information, they monitored its frequency and repetition across various social media channels. In the field section, the researchers actively participated in the gatherings as observers and data collectors, recording the behavior and conditions of the participants. This provided the authors with direct and unmediated data.To identify the patterns of protest, the study employed the K-function test in Geographic Information System (GIS) software. Additionally, the Getis-Ord Gi statistic was used to examine clustering boundaries and variable significance.
The Anselin Local Moran's I index was applied to determine the degree of spatial autocorrelation of protest
events. Furthermore, GIS maps were utilized to visualize the distribution and dispersion of protest throughout Tehran for more precise spatial analysis.In the qualitative component, the field observation technique was employed to identify the methods and tools of protests at the neighborhood level.
<strong> </strong>
<strong>Results and Discussion</strong>
The results of Ripley's K Function test indicate that the spatial pattern of protest points in Tehran is distributed in a clustered manner. The Getis-Ord Gi test further reveals that 38 neighborhoods, with confidence levels ranging from 90% to 99%, fall within the boundaries of protest hotspots.The protest hotspots in central Tehran include the neighborhoods of Tehran University, Valiasr, Fatemi, Jamalzadeh, Keshavarz, Jihad, Iranshahr, Ferdowsi, and Enqelab-Palestine. These hotspots are predominantly located in District 6 of Tehran, an area with a high concentration of educational institutions and academic facilities. The presence of these institutions has led to a significant presence of youth, women, and students, contributing to the formation of protest and gatherings.The eastern Tehran hotspot comprises neighborhoods such as West Tehran Pars, Northern Narmak, Elm-o-Sanat (Science and Technology), Majidabad, Ghanat Koohsar, and Kalad. These areas are primarily residential and home to the middle-class urban population.In western Tehran, neighborhoods such as Sadeghiyeh, Tarasht, Marzdaran, Abazar, Apadana, Ferdows, Sattarkhan, Teymoori, Bimeh, and Eram, which are predominantly residential and inhabited by middle-class residents, form another hotspot of protest.In northern Tehran, two hotspots with lower intensity compared to those in the central, eastern, and western areas have emerged. One hotspot includes the neighborhoods of Saei, Davoodieh, Seyyed Khandan, Kavousiyeh, and Niloufar, while the other, located further north, encompasses neighborhoods such as Velenjak, Ovin, Vanak, Sa’adatabad, and Darya. These neighborhoods are primarily inhabited by the middle and upper classes.The spatial continuity of neighborhoods located within the protest hotspots demonstrates a pattern of adjacency-based diffusion and reinforcement in the spread of protest.Additionally, the Anselin Local Moran's I test indicates that 16 neighborhoods in central, western, eastern, and northern Tehran exhibit high spatial autocorrelation of protest, influenced by neighborhood proximity and adjacency.Neighborhoods such as Tehran University, Keshavarz, Valiasr, Jamalzadeh, Ferdowsi, Iranshahr, and Enqelab-Palestine, along with their adjacent neighborhoods in central Tehran, have experienced a high number of protests. In western Tehran, four neighborhoods—Sadeghiyeh, Sattarkhan, Tarasht, and Marzdaran—and their neighboring areas have witnessed significant numbers of protests. In eastern Tehran, Northern Narmak and Elm-o-Sanat share similar conditions.In northern Tehran, three neighborhoods—Davoodieh, Kavousiyeh, and Ovin—have formed clusters that, along with their surrounding neighborhoods, have experienced numerous protests and exhibit high spatial autocorrelation. Statistical tests and quantitative analyses have shown that protest clusters formed in neighborhoods with more homogeneous social structures and a middle-class urban demographic. These protests were largely organized by women and youth, with the goal of attaining individual and social freedoms. Unlike the violent and intense protest of 2017 and 2019, which were mainly economically and livelihood-driven, the protests in the fall of 2022 in Tehran were centered on social and freedom-based demands.In the qualitative findings, one of the significant features of these protests was the extensive use of local neighborhood facilities and characteristics by the protesters. Neighborhoods, by providing social and spatial opportunities, created a conducive environment for protests. Protesters' geographic and social knowledge of the neighborhoods facilitated rapid mobility, evasion from security forces, and even nighttime protests from within their homes. As nightfall occurred, protesters had more opportunities to hide and escape from security forces. Additionally, many surveillance cameras in the city did not have sufficient visibility or lighting to capture protestors' faces.Moreover, protesters employed new methods, such as graffiti in public spaces, the destruction or alteration of government symbols, and scattered gatherings across neighborhoods, which reduced the security costs of protests while increasing their impact. Therefore, one spatial dimension of the protest was the destruction or alteration of symbols and urban landscapes that remind the public of the ruling political regime. Writing slogans on public space walls such as parks, streets, and altering street and alley names, as well as defacing portraits of political and military leaders, represented methods of resisting the ruling discourse—tactics not seen in previous protests. This type of protest had a significant spread throughout Tehran and became widespread at the neighborhood level. The use of this method was so extensive that in some neighborhoods, many walls were painted over, and the municipality began erasing
these slogans.Additionally, the dynamic nature of the protests was another prominent feature. Unlike past protests, the demonstrations were dispersed across neighborhoods, with protesters shifting locations and moving to various parts of the city, complicating the actions of security forces. In fact, the dynamic nature and mobility of the protest were a key strength for the protesters. During these protests, demonstrators generally started walking along a particular path or street, chanting protest slogans. The protest routes were not pre-determined, and depending on the security situation and police presence, the protests would shift to smaller streets or alleys, regrouping in another intersection or square.Furthermore, nighttime chanting and protests from within apartments introduced new dimensions to the protests that had not been observed before. In fact, the neighborhood and its geographical, spatial, and social features provided the necessary conditions for collective action (In this case, protest).
<strong>Conclusion</strong>
The autumn 2022 protest in Tehran exhibited significant differences in its spatial-social patterns and protest methods compared to past protest. Unlike the linear and centralized patterns of previous years, these protests occurred in a point-based and clustered manner across neighborhoods. Statistical analyses revealed that hot spots of protest were located in the center, west, east, and north of Tehran, and the geographical proximity of neighborhoods played a significant role in the spread of the protests. This cluster pattern reflected the influence of reinforcement and neighborhood dynamics in the formation of gatherings. The shift in protest patterns from main streets to neighborhoods was a creative response to previous confrontations and an effort to reduce the security costs for protesters.Neighborhoods, due to their homogeneous social structure, close social interactions, and geographical knowledge, provided a suitable environment for organizing and mobilizing collective action. Protesters employed diverse tactics, such as scattered gatherings, nighttime protests, graffiti, and repeated movement and relocation. Furthermore, the widespread spatial nature of the protest, which, on some days, resulted in protests across multiple neighborhoods with significant geographic distances between them, covering up to 60% of the city, made it challenging for security forces to manage.The results showed that these protests were largely organized by the middle class, women, and youth, with the goal of attaining social and individual freedoms. Neighborhoods, as new spatial-social units, provided opportunities for resistance and expression of dissent. These findings highlight the significant role of neighborhoods in urban protest, demonstrating that neighborhoods have become a key space for protests and collective resistance. Analyzing these developments can contribute to a better understanding of social dynamics and the management of urban protest in the future.<strong>Introduction</strong>
As the political hub of Iran, Tehran has witnessed several waves of protest and social protests over the past four decades, rooted in diverse political, economic, and cultural contexts and involving various socio-economic classes. The most recent protests and protest occurred in the autumn of 2022. Following the death of a 22-year-old woman in the custody of Tehran’s morality police during the final days of summer 2022, a wave of protest erupted in Tehran and other Iranian cities, lasting for several weeks. These incidents differed significantly from the spatial-temporal patterns and protest methods observed in Tehran’s previous decades of protest. From a socio-spatial perspective, these events can be regarded as a new form of protest and social protest.This study aims to analyze the distribution, intensification, and spread of the 2022 protest in Tehran using the theory of spatial diffusion in geography, identifying the spatial patterns of these incidents. According to this theory, phenomena spread across geographical areas through several mechanisms, including hierarchical diffusion, contagious diffusion, reinforcement diffusion, and spatial redistribution. The primary goal of this article is to identify the spatial diffusion patterns and spread of protest across Tehran using this framework.Additionally, the authors of this article seek to analyze the organization and direction of protests and protest through the lens of collective action theory. In this approach, neighborhoods and local spaces provide the framework and conditions necessary for collective action, including shared interests, organization, mobilization, and opportunities.The central research question of this study concerns the socio-spatial patterns of the autumn 2022 protest in Tehran and the role of neighborhoods as geographical and social units in these incidents. The preliminary response and hypothesis proposed are that these protests exhibited spatial-temporal patterns distinct from those of previous years, with critics and opponents employing different tools and methods.
<strong> </strong>
<strong>Materials and Methods</strong>
This study is applied in its objective and descriptive-analytical in nature, employing a mixed-methods approach with quantitative (Spatial Statistics Tools) and qualitative (field observation) components. The study area encompasses the city of Tehran and its neighborhoods.Data collection was divided into two parts: library/documentary and field methods. In the library section, due to the lack of an independent and reliable source publishing information on the protest, the researchers relied on data and reports from social media, international news agencies, and online platforms. To verify this information, they monitored its frequency and repetition across various social media channels. In the field section, the researchers actively participated in the gatherings as observers and data collectors, recording the behavior and conditions of the participants. This provided the authors with direct and unmediated data.To identify the patterns of protest, the study employed the K-function test in Geographic Information System (GIS) software. Additionally, the Getis-Ord Gi statistic was used to examine clustering boundaries and variable significance.
The Anselin Local Moran's I index was applied to determine the degree of spatial autocorrelation of protest
events. Furthermore, GIS maps were utilized to visualize the distribution and dispersion of protest throughout Tehran for more precise spatial analysis.In the qualitative component, the field observation technique was employed to identify the methods and tools of protests at the neighborhood level.
<strong> </strong>
<strong>Results and Discussion</strong>
The results of Ripley's K Function test indicate that the spatial pattern of protest points in Tehran is distributed in a clustered manner. The Getis-Ord Gi test further reveals that 38 neighborhoods, with confidence levels ranging from 90% to 99%, fall within the boundaries of protest hotspots.The protest hotspots in central Tehran include the neighborhoods of Tehran University, Valiasr, Fatemi, Jamalzadeh, Keshavarz, Jihad, Iranshahr, Ferdowsi, and Enqelab-Palestine. These hotspots are predominantly located in District 6 of Tehran, an area with a high concentration of educational institutions and academic facilities. The presence of these institutions has led to a significant presence of youth, women, and students, contributing to the formation of protest and gatherings.The eastern Tehran hotspot comprises neighborhoods such as West Tehran Pars, Northern Narmak, Elm-o-Sanat (Science and Technology), Majidabad, Ghanat Koohsar, and Kalad. These areas are primarily residential and home to the middle-class urban population.In western Tehran, neighborhoods such as Sadeghiyeh, Tarasht, Marzdaran, Abazar, Apadana, Ferdows, Sattarkhan, Teymoori, Bimeh, and Eram, which are predominantly residential and inhabited by middle-class residents, form another hotspot of protest.In northern Tehran, two hotspots with lower intensity compared to those in the central, eastern, and western areas have emerged. One hotspot includes the neighborhoods of Saei, Davoodieh, Seyyed Khandan, Kavousiyeh, and Niloufar, while the other, located further north, encompasses neighborhoods such as Velenjak, Ovin, Vanak, Sa’adatabad, and Darya. These neighborhoods are primarily inhabited by the middle and upper classes.The spatial continuity of neighborhoods located within the protest hotspots demonstrates a pattern of adjacency-based diffusion and reinforcement in the spread of protest.Additionally, the Anselin Local Moran's I test indicates that 16 neighborhoods in central, western, eastern, and northern Tehran exhibit high spatial autocorrelation of protest, influenced by neighborhood proximity and adjacency.Neighborhoods such as Tehran University, Keshavarz, Valiasr, Jamalzadeh, Ferdowsi, Iranshahr, and Enqelab-Palestine, along with their adjacent neighborhoods in central Tehran, have experienced a high number of protests. In western Tehran, four neighborhoods—Sadeghiyeh, Sattarkhan, Tarasht, and Marzdaran—and their neighboring areas have witnessed significant numbers of protests. In eastern Tehran, Northern Narmak and Elm-o-Sanat share similar conditions.In northern Tehran, three neighborhoods—Davoodieh, Kavousiyeh, and Ovin—have formed clusters that, along with their surrounding neighborhoods, have experienced numerous protests and exhibit high spatial autocorrelation. Statistical tests and quantitative analyses have shown that protest clusters formed in neighborhoods with more homogeneous social structures and a middle-class urban demographic. These protests were largely organized by women and youth, with the goal of attaining individual and social freedoms. Unlike the violent and intense protest of 2017 and 2019, which were mainly economically and livelihood-driven, the protests in the fall of 2022 in Tehran were centered on social and freedom-based demands.In the qualitative findings, one of the significant features of these protests was the extensive use of local neighborhood facilities and characteristics by the protesters. Neighborhoods, by providing social and spatial opportunities, created a conducive environment for protests. Protesters' geographic and social knowledge of the neighborhoods facilitated rapid mobility, evasion from security forces, and even nighttime protests from within their homes. As nightfall occurred, protesters had more opportunities to hide and escape from security forces. Additionally, many surveillance cameras in the city did not have sufficient visibility or lighting to capture protestors' faces.Moreover, protesters employed new methods, such as graffiti in public spaces, the destruction or alteration of government symbols, and scattered gatherings across neighborhoods, which reduced the security costs of protests while increasing their impact. Therefore, one spatial dimension of the protest was the destruction or alteration of symbols and urban landscapes that remind the public of the ruling political regime. Writing slogans on public space walls such as parks, streets, and altering street and alley names, as well as defacing portraits of political and military leaders, represented methods of resisting the ruling discourse—tactics not seen in previous protests. This type of protest had a significant spread throughout Tehran and became widespread at the neighborhood level. The use of this method was so extensive that in some neighborhoods, many walls were painted over, and the municipality began erasing
these slogans.Additionally, the dynamic nature of the protests was another prominent feature. Unlike past protests, the demonstrations were dispersed across neighborhoods, with protesters shifting locations and moving to various parts of the city, complicating the actions of security forces. In fact, the dynamic nature and mobility of the protest were a key strength for the protesters. During these protests, demonstrators generally started walking along a particular path or street, chanting protest slogans. The protest routes were not pre-determined, and depending on the security situation and police presence, the protests would shift to smaller streets or alleys, regrouping in another intersection or square.Furthermore, nighttime chanting and protests from within apartments introduced new dimensions to the protests that had not been observed before. In fact, the neighborhood and its geographical, spatial, and social features provided the necessary conditions for collective action (In this case, protest).
<strong>Conclusion</strong>
The autumn 2022 protest in Tehran exhibited significant differences in its spatial-social patterns and protest methods compared to past protest. Unlike the linear and centralized patterns of previous years, these protests occurred in a point-based and clustered manner across neighborhoods. Statistical analyses revealed that hot spots of protest were located in the center, west, east, and north of Tehran, and the geographical proximity of neighborhoods played a significant role in the spread of the protests. This cluster pattern reflected the influence of reinforcement and neighborhood dynamics in the formation of gatherings. The shift in protest patterns from main streets to neighborhoods was a creative response to previous confrontations and an effort to reduce the security costs for protesters.Neighborhoods, due to their homogeneous social structure, close social interactions, and geographical knowledge, provided a suitable environment for organizing and mobilizing collective action. Protesters employed diverse tactics, such as scattered gatherings, nighttime protests, graffiti, and repeated movement and relocation. Furthermore, the widespread spatial nature of the protest, which, on some days, resulted in protests across multiple neighborhoods with significant geographic distances between them, covering up to 60% of the city, made it challenging for security forces to manage.The results showed that these protests were largely organized by the middle class, women, and youth, with the goal of attaining social and individual freedoms. Neighborhoods, as new spatial-social units, provided opportunities for resistance and expression of dissent. These findings highlight the significant role of neighborhoods in urban protest, demonstrating that neighborhoods have become a key space for protests and collective resistance. Analyzing these developments can contribute to a better understanding of social dynamics and the management of urban protest in the future.https://esrj.sbu.ac.ir/article_105829_cd5f0745f17fe7b47efd738b554a2e0b.pdf