Desertification risk zoning using modified Medalus Model and hierarchical clustering method, case study: Sabzevar Badghous Plain

Desertification is a problem that is currently affecting many countries in the world, including Iran. This problem is seen not only in arid and semi-arid areas, but also parts of semi-humid areas. The purpose of this study is to investigate and zoning the intensity of desertification using the modified Medalus Model and hierarchical clustering method in the Baqous Plain of Sabzevar. For this purpose, effective criteria in desertification including climate, vegetation, soil, erosion, and selection management, and the geometric mean of the indicators were calculated. Data layers indicators related to each criterion were prepared using the GIS system. This information was scored based on the Medalus method and from the geometric mean of the indicators of each criterion, the final map of the status of each criterion was prepared and from the geometric mean of the criteria, the current map of the desertification of the region was prepared. Results showed that the criteria of vegetation, climate, and erosion were more effective than other factors in desertification of the region and high sensitivity and critical type was matched with the poverty of vegetation and the dryness of the climate, and work units 1 and 2 have the largest area of desertification types with high intensity. The results also showed that 21% of the study area is in the high sensitivity zone, 28% in the high and critical sensitivity zone, 17% in the low sensitivity zone, 28% in the low and critical sensitivity zone, and 6% in low sensitivity zone to erosion. 55.6% of the results of modified Modalus Model were obtained by significant clustering methods. According to the spatial distribution map of desertification intensity extracted from the model, it can be used as an auxiliary tool against desertification and prevent excessive destruction of the region in the future.