مجتبی
یمانی
استاد گروه جغرافیای طبیعی(ژئومورفولوژی)، دانشکده جغرافیا، دانشگاه تهران
author
مهران
مقصودی
دانشیار گروه جغرافیای طبیعی(ژئومورفولوژی)، دانشکده جغرافیا، دانشگاه تهران
author
شیرین
محمدخان
استادیار گروه جغرافیای طبیعی(ژئومورفولوژی)، دانشکده جغرافیا، دانشگاه تهران
author
انور
مرادی
دانشجوی کارشناسی ارشد هیدروژئومورفولوژی، دانشکده جغرافیا، دانشگاه تهران
author
text
article
2015
per
Researches in Earth Sciences
Shahid Beheshti University
2008-8299
6
v.
3
no.
2015
1
18
https://esrj.sbu.ac.ir/article_95650_311bfad2d81ffb380e2c0e744ef79e80.pdf
Monitoring and zonatione mass movements hazards in the Ardabil - Sarcham
رسول
صمدزاده
دانشیار گروه جغرافیا، واحد اردبیل، دانشگاه آزاد اسلامی
author
text
article
2015
per
Ardabile-Sarcham newly constracted road alone with Ardabile-Mianeh railway now underconstraction is the shortest communication highway of Ardabile province with the capital via Tabrize-Theran freeway.This road can potentially serve as a main touristic road the western and southwestern provinces as well as zanjan provinces . Mountainous slopes with unconsolidated lithological compositions escarpment rocky unstable predominant on the road , because of the nature of this dynamics are affected by numerous factors, of which naturals and human causes to this two road has always been exposed to a variety of environmental hazards that mass movement , especially the landslide and rockfall are the most common. Monitoring and mass movements hazard zonation, the main objective is of the present study.To do this have been used from quantitative way the chi-squre method . First,by using aerial photographs 1:20000 , the geologyical maps 1:100000 and fields studies, landslide distribution map was prepared. In order of enhance the accuracy and easy of analysis and description of spatial information such as : lithology layer , structural marks , slope and vegetation and etc were digitalized. For statistical analysis have used spss16 software. Then in order to calibrate the sensivity of the net work units to landslide , a map final is drawn . In the final step on thee field survey , and the model has been assessed zoning map and strategies for dealing with it are proposed.
Researches in Earth Sciences
Shahid Beheshti University
2008-8299
6
v.
3
no.
2015
19
33
https://esrj.sbu.ac.ir/article_95665_4e7a1dd9c18609396909479c731d42be.pdf
Detection of climate change with extreme precipitation indices in great Khorasan
محمود
احمدی
دانشگاه شهید بهشتی
author
حسن
لشکری
دانشگاه شهید بهشتی
author
مجید
آزادی
دانشیار گروه هواشناسی، پژوهشکده هواشناسی، سازمان هواشناسی
author
قاسم
کیخسروی
دانشگاه شهید بهشتی
author
text
article
2015
per
Climate changes with change in climate models and disrupt the order of ecosystems, imports Serious consequences on the environment. Changes in weather patterns can led to the Severe flooding, Extreme heat and cold, More frequent droughts, Sea Level Rise, global warming and Permanent ice melting. Even each of these phenomena can put one of the region's food supply at risk. In this reaearch, for detecting the climate change in great Khorasan, were use 25 year synoptic meteorological stations(14 station) statistics from1/1/1987 to 31/12/2011. Results show that few stations such as Ghochan (10 indices), Bojnourd (7 indices), Golmakan (5 indices), Sabzevar (3 indices) show an increase in the number of extreme precipitation indices. Ferdows, Torbat heidarieh, Ghaen and Nehbandan stations 100% and Birjand. Tabas, Gonabad, Mashhad and Kashmar stations over than 90% suffer from Rainfall changes. Among the indices, Consecutive wet days index(CWD) with 92.9% , Total annual precipitation wet days index (PRCPTOT) with 85.7%, Show the largest percentage decline. So in the north-west of Iran, except of Ghochan and to some extent Bojnourd , other station have experienced drastic changes in precipitation In the last 25 years
Researches in Earth Sciences
Shahid Beheshti University
2008-8299
6
v.
3
no.
2015
34
52
https://esrj.sbu.ac.ir/article_95680_e228c5ca4424f32e12acc8676f0c25b8.pdf
Possible effects of climate change on wheat crop in the state of Tehran
علیرضا
شکیبا
دانشگاه شهید بهشتی
author
سمانه
شب خیز
دانشگاه آزاد اسلامی واحد شهرری
author
فرشید
حشمدار
اداره کل هواشناسی استان تهران
author
text
article
2015
per
Effects of climate change on agriculture and food security is one of the most important issues in the world. Wheat consist a high proportion of land under cultivation and is one of the most important food sources for people. Tehran province with 60,125 hectares acreage of wheat (1389-1388 season) and producing 6/3795 tones in the same year produced the highest yield among other provinces. The purpose of this study was to evaluate the effect of climate change on yield of wheat production in Tehran province. Meteorological data for 58 years (2009-1951 AD) of Tehran weather station was chosen in this study. After validation of the ClimGen statistical model for the study area, climate data of 2020 to 2050 were put into the model. Based on climate change scenarios A2 and B2 in two modes (1, increased CO2, 2- Increasing CO2 and temperature), soil variables associated with climate and agricultural data results were put into APSIM agriculture model. In complex scenarios A2 and B2, with rising CO2 levels respectively 700 ppm and 525 ppm alone and without the assumption of temperature fluctuations, production is increased by 28% and 13% respectively compared to the control scenario. But in the next scenario involving a temperature increase of 2 and 4 ° C respectively reduces production 10% and 12% compared to the control scenario. The study results of researchers who have studied on Co2 effects on plants, approve the positive impacts of CO2. Most researches show the negative impact of temperature rise to the product to which this study confirms
Researches in Earth Sciences
Shahid Beheshti University
2008-8299
6
v.
3
no.
2015
53
65
https://esrj.sbu.ac.ir/article_95683_eeeaf0cd6dbbde5632e6e761abbf23d2.pdf
ش
سعیده
سنماری
دانشگاه بین المللی امام خمینی (ره)، قزوین
author
text
article
2015
per
In this research, biostratigraphy of the Pabdeh Formation in North Ilam was studied. The study of calcareous nannofossil led to recognition of 77 species and 28 genera. According to the first occurrence of index species and distribution fossil assemblages, zones (Heliolithus kleinpellii Zone, Discoaster mohleri Zone, Heliolithus riedelii Zone, Discoaster multiradiatus Zone, Tribrachiatus contortus Zone, Discoaster binodosus Zone, Tribrachiatus orthostylus Zone, Discoaster lodoensis Zone, Discoaster sublodoensis Zone, Nannotetrina fulgens Zone, Discoaster tani nodifer Zone, Discoaster saipanensis Zone, Chiasmolithus oamaruensis Zone, Isthmolithus recurvus Zone, Sphenolithus pseudoradians Zone, Ericsonia subdisticha Zone, Helicosphaera reticulata Zone, Sphenolithus predistentus Zone, Sphenolithus distentus Zone) of Martini (1971) equivalent to bio zones (CP5- CP19) of Okada and Bukry (1980) at Reno section were identified. As a result of this study and based on the obtained bio zones, age of the Pabdeh Formation in North of Ilam, is Late Paleocene (Thanetian) to Early Oligocene (Rupelian).
Researches in Earth Sciences
Shahid Beheshti University
2008-8299
6
v.
3
no.
2015
66
79
https://esrj.sbu.ac.ir/article_95692_457c92eed439c4a76ab234e08ccc90c8.pdf
Petrology and geochemistry of mafic rocks from Bibi Maryam ophiolite suite, Neh fault zone, east Iran
نوشین
صابرشهرکی
دانشگاه سیستان و بلوچستان
author
علی
احمدی
دانشگاه سیستان و بلوچستان
author
مصطفی
قماشی
دانشگاه سیستان و بلوچستان
author
text
article
2015
per
The Bibi Maryam ophiolite suite, north of Neh fault zone, east Iran, is a part of Neh ophiolitic complex of Cretaceous age. Mafic rocks of this suite are basalt, diabase and gabbro. Lack of metamorphic rocks of greenschist, blueschist and amphibolite facies, absence of cumulate peridotite and gabbro in spite of occurrence of mantle peridotite and isotropic gabbro, absence of discrete diabase sheeted dikes, scarcity of pelagic limestone and radiolarian chert, and enrichment of mafic rocks in incompatible elements and LREEs in comparison to normal MORB are indicative of the immature nature of the Bibi Maryam ophiolite suite. The primary magma of the mafic rocks has been abyssal tholeiitic. The average amounts of TiO2 and K2O are 0.47 and 0.19, respectively, indicating the magma has been of NMORB type. However, regarding the trace element and REE contents of the mafic rocks, the magma should have been enriched in incompatible elements compared to NMORB. Based on these geological and geochemical evidence, the Neh fault zone is thought to be an aborted mid-ocean rift.
Researches in Earth Sciences
Shahid Beheshti University
2008-8299
6
v.
3
no.
2015
80
98
https://esrj.sbu.ac.ir/article_95701_825e23b21441fb67ebef19d76b43054a.pdf
Thermobarometry of Sirjan’s amphibolite based on Zr content in Sphene (Titanite) and Rutile
الهام
صفرزاده
Shahid Beheshti University
author
فریبرز
مسعودی
Shahid Beheshti University
author
سید محمد
پورمعافی
Shahid Beheshti University
author
text
article
2015
per
Part of the metamorphic complex of south of Sirjan has made by amphibolite units. In this region, amphibolites are found with garnet muscovite schist and hornblende schist. Their lithological compositions include amphibole with magnesio-hornblende and tschermakite composition, sodic plagioclase (Ab70), epidote, quartz and biotite, with sphene and rutile as minor minerals. In this study, temperature and pressure conditions of amphibolite are evaluated by using Ti and Zr content in the rutile and sphene, minerals.
The electron microprobe analysis of sphene and rutile minerals on selected samples show, the average of Zr= 317.57 ppm, TiO2= 37.23 wt% in sphene and Zr = 439.57 ppm, TiO2 = 98.48 wt% in rutile. Thermobarometry of sphene and rutile based on Watson, Ferry and Tomkins calibrations show that the range of temperature and pressure of the amphibolites based on sphene is T = 608-691ºC and based on rutile is T = 572-723ºC, P = 7.6- 9 Kbar. Based on these results and compatibility with the range of different metamorphic facieses, amphibolites were formed during regional metamorphism in high grade amphibolite facies.
Researches in Earth Sciences
Shahid Beheshti University
2008-8299
6
v.
3
no.
2015
99
117
https://esrj.sbu.ac.ir/article_95706_c57eaafa19ad9ead51a04db60d0d9ac1.pdf