Introduction

Tourism is one of the largest and fastest-growing industries around the world (Sharples, 2002). This industry plays and important role in the economic so that the average growth of tourism incomes has been duplicated in last two decades (Nasarudin & Bahar, 2013). Tourism industry comprises main component of global economy, and it is considered as an industry influencing the cultural, social and environmental issues. Therefore, most countries try to attract tourism capital through improving needed facilities and services for tourists (Elgin & Elveren, 2024; Sofronov, 2017). Human civilizations have been benefited from ecosystem services more than 5000 years (Boon & Raven, 2012; Ellis, 2021; Richter, 2014; Tallis & Kareiva, 2005). Rivers, by providing water and the fertile alluvial plains, have have occupied a central place in human history, and sustained the first human settlements, and in so doing helped foster the accumulation of wealth based on agriculture and trade, allowed the great past civilizations to flourish (Kumar & Sajnani, 2020; Prideaux et al., 2009). These wonderful locations have natural attractions and also are appropriate for wide range of human activities such as transport corridors, food resources, providing drinking, industry and agricultural water, energy production, and also in recent years for visiting, spending leisure time and tourism (Prawira et al., 2021; Prideaux et al., 2009).

The concepts of ecotourism and geotourism have emerged in tourism literature, experiencing rapid global growth (Chylińska & Kołodziejczyk, 2018; Tesfa & Zewdie, 2023; Xu et al., 2023). The expansion of such tourism in any region necessitates specific conditions and facilities, such as geological phenomena, geomorphic landforms, and natural ecosystems. In recent years, river-based tourism, though observation of landscapes and utilization of fluvial environments as one kind of tourism, has gradually raised its position among international tourists (Prideaux et al., 2009; Silva & Mattos, 2020).

In river-based tourism, there exists a direct relationship between river ecosystems and tourism. Rivers, as natural ecosystems, offer numerous aesthetic attractions for tourists by providing unique morphological features, serene and beautiful environments, historical significance, transportation and travel opportunities on the river, facilitation of tourism development through water supply, provision of water for agricultural production, and generation of electricity required for tourism activities, thereby promoting tourism development in various regions (Arif et al., 2022; Hsu et al., 2020; Silva & Mattos, 2020; Xu et al., 2023).

Nowadays, river tourism serves as a platform for fostering interactions between nature and humans, and various recreational and sports activities including adventure water activities, water-rafting, river-cruise, kayaking, boating, tubing, swimming, fishing, recreation, river walking, and river travel, are increasingly popular among people and in high demand among tourists worldwide, particularly those seeking challenges, adventures, experiences, and satisfaction (Fachrudin & Lubis, 2016; Lin et al., 2022; Moreira, 2018; Prideaux, 2023).

River tourism represents a lucrative trade with the potential of making a major contribution to the local economy through employment in cruise ships, pleasure boats, parks, and recreational facilities along riverbanks (Shakiry, 2007). Implementing tourism projects and activities along rivers can offer potential benefits to local communities and enhance the economic conditions of these areas.

Iran boasts diverse geographical conditions, encompassing 11 of the 13 recognized global climates. These conditions have resulted in substantial environmental, nature-based tourism, recreational, and economic capabilities. The tourism industry in Iran possesses considerable potential for growth and expansion. According to the World Tourism Organization, Iran ranks tenth in historical and cultural attractions and fifth in natural attractions globally. In recent decades, the development of tourism in Iran has gained importance in the national economy, aiming to increase foreign exchange earnings and reduce dependence on oil revenues. Given the country's high potential in attracting tourists, it is imperative to adopt policies that enhance the positive role of tourism in the nation.

The Qazvin region is situated on the southern slopes of the Alborz Mountains, and its northern, western, and southern parts have mountainous topography. The climatic diversity and moderate rainfall, particularly in the mountainous areas of the province, have created beautiful and diverse landscapes, offering numerous tourism potentials and attractions, making this region suitable for tourism and related activities. The Qezel Ozan River, one of Iran's longest rivers, originates from the highlands of Kurdistan and East Azerbaijan and, after following a sinuous path, joins the Shahrood River in Manjil to form the Sefidrud River. The banks of this river evoke memories of the ancient Andean civilization, one of the early civilizations of the first millennium BCE. The Qezel Ozan River and its surrounding areas, from environmental, biological, ecological, and social perspectives, can play a significant role in attracting tourists and serve as a potential site for river tourism, including adventure tourism activities such as rafting, kayaking, river cruising, fishing, swimming, etc.

River-based tourism can attract numerous tourists and enthusiasts from various parts of the country. Therefore, recognizing and introducing the capabilities of the Qezel Ozan River can lead to increased awareness among local communities, attract tourists, develop and advance the tourism cycle, and ultimately boost the economic cycle and job market in the region. Hence, this study examines the river tourism potentials of the Qezel Owzan River in the Tarom area, aiming to identify and introduce the river's capabilities to local communities and tourists.



Methodology

The study area is situated along a 15-kilometer stretch of the Qezel Ozan River and its surrounding region, extending from Gilvan to the vicinity of the Sefidrud Dam Lake, known as Qal’eh Samiran. This area lies between the geographic coordinates of 49° 06' E and 36° 47' N to 49°14' E and 36°44' N, spanning across the provinces of Zanjan, Qazvin, and Gilan (Fig. 1). The Qezel Ozan River is one of the longest rivers of Iran. Its source areas is Chehel Cheshmeh highlands in the Divandareh district of Sanandaj County. Then, the river flows through the provinces of Kurdistan, Zanjan, East Azerbaijan, and Ardabil before reaching the Caspian Sea near Hasankiyadeh in Lahijan, Gilan Province. Within the study area, the river nourishes olive orchards and rice Paddy field, eventually entering the Manjil Dam Lake (Sefidrud Reservoir) near the city of Manjil in Gilan Province. The minimum elevation in Qazvin Province (approximately 300 m asl) is found in the Tarom-e Sofla region, adjacent to the Sefidrud Lake. Overall, the elevation within the Tarom region varies between 300 and 2800 meters.

The mountainous terrain of the region can be classified into four distinct zones:

-Western Highlands: Including Qajar, Qoozi, Jungle, and Leseleh Daghi Mountains. These form the western boundary of Tarom-e Sofla and Zanjan Province, reaching a maximum elevation of 2485 m asl (Qajar Mountain).

-Southern Highlands: Comprising the Sandan Daghi, Saren Yasar, Biyuk Dash, Dash Bolagh, Soltan Pir, Bahavor, Soltanlu, Goli Bolagh, Biyanlu, and Kamarsiya Mountains. These mountains demarcate the southern boundary of Tarom-e Sofla and Zanjan Province.

-Eastern Highlands: Including Asbak and Sanjarsar Mountains, with some peaks reaching elevations up to 1300 m asl.

-Central Highlands: including Shamadasht, Sefidkuh, Khaneh Gaduk, Qorkhlar, Goshne Jar, Dagh Daghan, Door, Zakan, Shakhani, and Qarah Dash Mountains. These ranges are separated by numerous deep valleys across the central area of the region.

Geologically, the study area falls within the Western Alborz structural zone. Along the Qezel Ozan River course, various geological formations are exposed including: The Karaj Formation (Eocene), consisting of sandstone, shale, limestone, and minor volcanic tuff and ash; Neogene deposits characterized by red beds with gypsum and conglomerates; Quaternary (Pliocene) units comprising gravel-covered fluvial terraces (Fig. 2).



Land use in the region includes agricultural lands, rangelands, forested and woodland areas, as well as barren lands. The mountainous areas generally exhibit sparse tree cover and are predominantly rangeland. Common vegetation includes juniper (Juniperus spp.), olive (Olea europaea), pomegranate (Punica granatum), fig (Ficus carica), hazelnut (Corylus spp.), and hawthorn (Crataegus spp.) (Fig. 3).

According to the De Martonne climate classification, Tarom County falls under a cold semi-arid climate, while the northern highlands experience a cold semi-humid climate. From an ecological perspective, the region hosts diverse ecosystems, including forest, mountainous, steppe, rangeland, and wetland-riverine habitats. The average annual precipitation of the study area is approximately 250 mm, and the mean monthly temperature is around 19°C. Based on data from the Gilvan hydrometric station, the mean annual discharge of the Qezel Ozan River is estimated at 47.4 m3/s.

In this study, the river tourism potential of the Qezel Ozan River in the Gilvan region was assessed using a range of environmental parameters, including accessibility, geology, land use, services, slope, flow velocity, water turbidity, and river width.

Accessibility: Accessibility is one of the key factors in evaluating river tourism potential. To create the accessibility layer, the main and secondary roads leading to the selected river reaches were initially digitized using Google Earth environment. Subsequently, roads were classified into three levels (primary, secondary, and tertiary) based on field surveys. Each river reaches was then prioritized according to the proximity and length of access routes.

Geology: The geological map of the study area was prepared using the 1:250,000-scale geological map of Zanjan. For prioritizing each river reach, the number of different lithological formations on both the left and right banks (up to a distance of 500 meters) was identified. Sections with greater geological diversity were assigned higher priorities.

Land Use: Land use data for the region were derived from the national land use map (Ministry of Agriculture Jihad), Google Earth imagery, and field observations. Land use types within 500 meters on both sides of the river were classified in a GIS environment. River reaches were then prioritized based on land use diversity, with the highest diversity receiving the highest priority.

Services: To evaluate service availability, the distance between each river reaches and the nearest service facility (including accommodations, sanitary facilities, supermarkets, etc.) was measured. Sections closer to such amenities were given higher priority.

Slope: Topographic variables such as elevation and slope were derived from the ALOS Digital Elevation Model (DEM) obtained from the Alaska Vertex website and processed using GIS software. River sections with gentler slopes were prioritized higher, as steep slopes may hinder tourism accessibility and safety.

Flow Velocity: River flow velocity was measured during fieldwork for each reach. In terms of tourism suitability, lower flow velocities are more favorable. Therefore, the following classification was applied: priority 1= velocity < 2 m³/s, priority 2= velocity 2–3 m³/s, priority 3= velocity 3–4 m³/s, priority 4= velocity > 4 m³/s.

River Width: The average width of each river reach was calculated based on measured cross-sectional widths. A wider river generally implies lower depth and velocity, enhancing its suitability for recreational activities. Thus, river reaches were ranked as follows: priority 1= width > 100 m, priority 2= width 75–100 m, priority 3= width 50–75 m, priority 4= width < 50 m.

where n represents the number of samples within a specific group, and N denotes the total number of samples. The value of D varies between 0 and 1. A value close to 0 indicates very high diversity, while a value approaching 1 signifies the dominance of one or a few specific groups and, consequently, low diversity.

For criteria such as accessibility, services, slope, velocity, turbidity, and river width, the Power-Ranking method was used for weighting. In this approach, factors are ranked by expert judgment and final weights are computed based on their ranks.

In this model, n represents the number of variables, rj denotes the significance and rank of each variable, and p is determined based on expert judgment.

To normalize the values of different variables and achieve a uniform range (0 to 1), Min-Max normalization was applied:

Expert opinions were gathered through questionnaires administered to specialists and stakeholders in the tourism sector. The Analytic Hierarchy Process (AHP) method was employed for final weighting of the effective layers using the Expert Choice software .

. Following the generation of the final suitability map, all river reaches were classified into four categories: low, moderate, good, and very good in terms of river tourism potential.