Geomorphological Features and Vegetation Types Analysis of Pasturelands Using DEM

Copyright @ Corresponding author: Tursunoy Yuldasheva 132 Global Journal of Research in Agriculture & Life Sciences ISSN: 2583-4576 (Online) Volume 05 | Issue 05 | Sept.-Oct. | 2025 Journal homepage: https://gjrpublication.com/gjrals/ Research Article Geomorphological Features and Vegetation Types Analysis of Pasturelands Using DEM *Tursunoy Yuldasheva Tashkent Institute of Irrigation and Agricultural Mechanization Engineers (TIIAME) NRU Tashkent, Uzbekistan INTRODUCTION Pasture ecosystems play a vital role in ensuring livestock productivity and maintaining ecological balance in mountainous regions. However, due to excessive grazing, land degradation, and lack of scientific management, pasture areas in Uzbekistan, particularly in the Tashkent region, face serious challenges. Effective use of pastures requires a precise understanding of their geomorphological characteristics and vegetation distribution. Digital Elevation Models (DEM) provide a modern geoinformation tool that enables accurate delineation of relief-based zones. At the same time, identifying vegetation types in each zone makes it possible to assess the ecological potential of pastures and develop management strategies adapted to natural conditions [1-2]. The Bustanlik district is one of the largest pasture regions in Tashkent province, characterized by diverse relief conditions ranging from foothills to high mountains. These variations directly influence vegetation cover, soil properties, and the productivity of grazing lands. So far, detailed geomorphological mapping of pastures based on DEM and comprehensive classification of vegetation types in the territory of Bustanlik district have not been carried out in scientific research. Therefore, the main aim of this research is to analyze the geomorphological zoning of pastures in the Bustanlik district using DEM and to identify the dominant vegetation types in each zone. The findings of this study are expected to contribute to sustainable pasture management, ecological monitoring, and the development of evidence-based land-use strategies in Uzbekistan. MATERIALS AND METHODS The scientific and ecologically sustainable use of pasture lands is one of the key factors in preserving the forage base and increasing efficiency in livestock farming today. According to the current legislation, pasture lands are classified as agricultural lands and are legally managed as a separate category. However, in practice, they are often evaluated as a single type of “pasture,” without considering their diverse ecological and territorial characteristics, which causes numerous problems [8]. According to Article 9 of the Land Code of the Republic of Uzbekistan, lands are divided into categories based on their primary use, and this is reflected in land cadastre documents. This provision establishes the legal framework for defining Abstract This study focuses on the geomorphological and vegetation zoning of pastures in the Bostanliq district using a Digital Elevation Model (DEM). Based on elevation, the territory was divided into four main geomorphological zones: foothill pastures (500–1000 m), piedmont pastures (1000–1200 m), mountain pastures (1200–2500 m), and high-mountain pastures (above 2500 m). According to the analysis, the total pasture area covers 187,833 ha, of which 48,785.26 ha belong to foothill pastures, 44,911.27 ha to piedmont pastures, 83,830.58 ha to mountain pastures, and 10,305.89 ha to high-mountain pastures. Each geomorphological zone is characterized by distinct vegetation types reflecting differences in altitude, climate, and soil conditions. The integration of DEM-based zoning with vegetation analysis provides a comprehensive scientific basis for sustainable pasture use, monitoring of ecological changes, and the development of management strategies adapted to local natural conditions. Keywords: Pasturelands, Geomorphological zoning, Vegetation types, Digital Elevation Model (DEM), GIS analysis, Bustanliq district, Sustainable pasture management, Mountain ecosystems, Remote sensing, Ecological assessment. Global J Res Agri Life Sci. 2025; 5(5), 132-138 @ 2025 | PUBLISHED BY GJR PUBLICATION, INDIA 133 the purpose of land use, as well as for its management and protection. Therefore, it is essential to classify pasture lands not only as a single category but also by taking into account their natural-geographical and ecological characteristics. Such classification makes it possible, on the one hand, to determine the load and restrictions for each pasture zone, and on the other hand, to prevent their degradation. The concept of sustainable pasture use requires compliance with ecological conditions of the land, as well as consideration of socio-economic needs for the population’s livelihood and farming activities. Harmonious development of society presupposes the coordination of natural and technological systems. Hence, socio-economic challenges, which are closely connected with ecological and economic problems, should be addressed as a priority. According to A.R. Babajonov, the first priority in the use of pastures in Uzbekistan is their regionalization and zoning. Based on natural conditions, pastures of the country are divided into desert, foothill (adir), mountain, and high-mountain zones [3]. It should be noted that the government of Uzbekistan has taken significant measures to improve the situation in pasture management [5]. For example, the Resolution of the Cabinet of Ministers and, in particular, the Decree of the President of the Republic of Uzbekistan No. PF-219 dated December 28, 2023, “On the State Program for the Digitalization of Land Resource Management and the Use of Pastures”, are among the most important policy initiatives. In pasture areas, relief factors play an important role in determining the distribution and area of vegetation types [4]. This is because parameters such as elevation, slope, and aspect directly influence the density and spatial arrangement of plant cover. Therefore, before using remote sensing data, it is necessary to identify the main characteristics of the terrain. One of the most widely used tools for this purpose is the Digital Elevation Model (DEM) (FIGURE 1). FIGURE 1. The elevation data were derived from open-source Digital Elevation Model (DEM) sources. DEM datasets are freely accessible through open sources, with the most commonly used being SRTM (Shuttle Radar Topography Mission), ASTER GDEM (Advanced Spaceborne Thermal Emission and Reflection Radiometer Global DEM), and Copernicus DEM. Their resolution varies between 90 meters and 30 meters, and the appropriate option is selected depending on the purpose of scientific analysis. In this study, the selected DEM data were imported in raster format into the ArcGIS software for further processing (FIGURE 2). Global J Res Agri Life Sci. 2025; 5(5), 132-138 @ 2025 | PUBLISHED BY GJR PUBLICATION, INDIA 134 FIGURE 2. The Digital Elevation Model (DEM) of the Bostanliq district was generated using ArcGIS software. Initially, it was essential to delimit the study area by extracting only the pasture zone from the total territory. This procedure was performed in ArcGIS using the “Clip Raster” and “Extract by Mask” functions, which enabled the removal of irrelevant data and the preservation of the target region. Subsequently, potential errors in the raster dataset, such as artificial depressions (“sinks”) in low-lying areas, were corrected through the “Fill” function to ensure hydrological consistency [5]. In the following stage, terrain parameters were derived to characterize the relief of the study area. The “Spatial Analyst Tools → Surface” module in ArcGIS was employed to generate a set of derivative maps, including: • Slope map – quantifying the steepness of the terrain; • Aspect map – indicating the directional orientation of slopes; • Hillshade map – producing a three-dimensional shaded relief visualization [6]. These topographic derivatives significantly enhance both visual interpretation and quantitative analysis. In particular, they provide valuable insights into the spatial distribution of pasturelands across elevation zones, slope gradients, and their exposure to solar radiation, which are crucial factors for evaluating pasture suitability and degradation risks [7]. RESULTS AND DISCUSSION According to the State Cadastre Chamber under the Cadastre Agency of the Ministry of Economy and Finance of the Republic of Uzbekistan, as of January 1, 2024, the total land area of Tashkent region amounts to 1,514,926 hectares. Among this, Bustanlik district accounts for 493,421 hectares, representing approximately 33% of the regional territory. Within the district’s land resources, pasturelands cover 187,833 hectares. The distribution of these pasture areas across different elevation zones is presented in the following table (Table1) Table-1 Distribution of Pasturelands in Bostanliq District by Elevation Zones Pasture zones Elevation range (m) Pasture area by zones (ha) Foothill pastures 500-1000 48 785,26 Piedmont pastures 1000-1200 44 911,27 Mountain pastures 1200-2500 83 830,58 High mountain pastures 2500+ 10 305,89 Total pasture area: 187 833,0 Note: Elevation data were derived from open-source DEM (Digital Elevation Model) datasets and processed in ArcGIS software. Bustanlik District is located in the northeastern part of Tashkent Region and represents one of the most fertile natural landscapes of the mountainous areas of Central Asia. The district’s relief is characterized by a complex morphological structure, with the main part occupied by the Chatkal, Ugam, and Piskom mountain ranges belonging to the Western Tien Shan system. A relief map generated from the Digital Elevation Model (DEM) clearly demonstrates the steepness of the Global J Res Agri Life Sci. 2025; 5(5), 132-138 @ 2025 | PUBLISHED BY GJR PUBLICATION, INDIA 135 elevation gradients, with mountain slopes varying between 10° and 45°. The eastern and southeastern sectors are situated at elevations ranging from 2,500 to 4,300 meters, where extensive high-mountain meadows are widely developed [9]. FIGURE 3: Digital modeling of the relief of Bostanliq District and its morphometric indicators based on geospatial data. In the process of pasture zoning, the natural conditions, relief, and soil–climatic characteristics of each territory were taken into account, and their exact areas were calculated. As a result of these calculations, the distribution of pastures across desert, foothill, mountain foothill, and mountain zones was determined. The total area of each zone was measured using GIS tools and subsequently visualized on maps. However, a comprehensive characterization of pasture ecosystems cannot be limited to area measurements alone. Therefore, the study also examined the types of vegetation distributed across these zones. Furthermore, according to the implementation of the Resolution of the Cabinet of Ministers of the Republic of Uzbekistan dated April 23, 2018, No. 299, “On improving the procedure for defining the boundaries of administrativeterritorial units, inventorying land resources, and conducting geobotanical surveys in pastures and hayfields,” geobotanical investigations were carried out in the pasture lands of Bostanliq District by the State Scientific Design Institute Uzdavyerloyiha under the Ministry of Agriculture of the Republic of Uzbekistan (Figure4) FIGURE 4. Distribution of vegetation types Global J Res Agri Life Sci. 2025; 5(5), 132-138 @ 2025 | PUBLISHED BY GJR PUBLICATION, INDIA 136 In my research, I also analyzed the 2018 geobotanical survey reports and maps conducted by the State Scientific Design Institute “Uzdavyerloyiha,” since the floristic composition of pastures played an important role in delineating pasture regions within the district. The study of relief, climate, and vegetation cover is essential for developing prospective land management plans, particularly in the context of reforming the livestock production system and ensuring the sustainable use of pasture resources. As part of the research, I thoroughly examined the vegetation type attributes within the polygon layers of the pasture areas and calculated the mean, minimum, and maximum values of the Digital Elevation Model (DEM) and its derived layers for each vegetation type polygon (Table2) Table-2 Pasture types of Bustonlik district by ecological zones and their respective areas (hectares) Pasture zones Plant types Pasture area (ha) Foothill pastures (500-1000) 169 986,46 205 1096,6 221 244,78 223 1064,89 224 12460,67 225 4068,84 226 814,85 237 2679,82 242 251,02 244 9286,8 245 1939,39 247 4863,9 248 251,31 249 1831,33 250 447,42 257 1199,05 259 473,99 260 4106,57 261 687,96 265 29,61 Total: 48 785,26 Piedmont pastures (1000-1200) 223 2098,36 224 4493,84 225 636,93 226 1542,61 237 13,06 242 705,73 244 4147,28 244a 755,66 245 2255,76 247 4160,94 248 1205,94 249 593,67 250 2269,9 257 3765,62 259 5343,17 260 8959,11 261 135,07 264 576,25 265 86,76 274 1165,61 Total: 44 911,27 Mountain pastures (1200-2500 metr) 223 3181,86 224 381,44 Global J Res Agri Life Sci. 2025; 5(5), 132-138 @ 2025 | PUBLISHED BY GJR PUBLICATION, INDIA 137 226 418,39 242 43,86 244 18584,03 244a 98,98 245 4449,29 247 3117,42 248 138,89 249 28,2 250 1347,7 257 3841,95 259 6909,39 260 12120,21 261 139,67 264 21,31 265 3,61 274 4342,41 276 21300,23 287 3361,74 Total: 83 830,58 High mountain pastures (2500 metrdan yuqori) 260 2916,46 276 7389,43 Total: 10 305,89 Total pasture area: 187 833,00 As presented in the table, the pastures of Bustonlik district were classified according to their ecological zones, and their respective areas were determined. CONCLUSION This study highlights the importance of applying geoinformation technologies, particularly Digital Elevation Models (DEM) and GIS-based analyses, in the classification and assessment of pasture resources in Bustonlik district. By integrating relief parameters such as elevation, slope, and aspect with vegetation distribution data, a detailed spatial differentiation of pastures was achieved. The results demonstrated that pastures in the district are distributed across four main ecological zones desert, foothill, mountain, and high-mountain covering a total of 187,833 hectares. Each ecological zone exhibits distinctive vegetation types and areas, which were quantified and mapped for the first time with high precision. The use of geobotanical survey reports (2018) in combination with DEM-derived morphometric indicators enabled a comprehensive evaluation of vegetation–relief relationships. This integrated approach not only allows for more accurate monitoring of pasture ecosystems but also provides a scientific basis for sustainable land management and livestock development strategies. Overall, the findings confirm that reliance solely on general “pasture” classifications without considering geomorphological and ecological diversity leads to inefficiencies in pasture use and potential degradation. Therefore, scientifically grounded regionalization of pastures is essential for ensuring their ecological stability, improving forage productivity, and supporting long-term rural development planning in Uzbekistan. REFERENCES 1. Smith, J., & Zhao, L. (2021). GIS-based approaches for pasture land assessment in semi-arid regions. Journal of Arid Environments, 45–59. 2. Gomez, R., & Aliyev, N. (2022). Remote sensing and GIS tools in pasture land monitoring. Environmental Monitoring and Assessment, 298–310. 3. Babajonov, A. R. (n.d.). Management of Land Resources (p. 41). 4. 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