Spatial distribution of desertification hazard in Sabzevar using IMDPA model

Desertification is a global issue with serious implications worldwide on biodiversity, eco-safety, poverty eradication, socio-economic stability, and sustainable development. The most efficient methods for assessing desertification intensity are experimental methods. The aim of this study was to assess desertification hazard in Sabzevar using the GIS and IMDPA model. The IMDPA model was applied to evaluate the desertification intensity in Sabzevar. For this purpose, first the land unit map (geomorphologic facies) was created using slope, geology, vegetation cover, land use, Landsat 5 and Google Earth satellite images in 4 units, and 10 types and 96 facies were identified. Then, in each work unit, all the criteria were valued based on the selected indices which resulted in the qualitative mapping of each criterion based on the geometric mean of the indices. The mapping of each group was done based on the geometric mean of the studied criterion. Then, the desertification intensity map of the region was obtained using a geometric average of all groups. The results showed that water, irrigation, and erosion have the most severe impact on desertification with weighted means of 2.94 and 2.72, respectively. Sabzevar was divided into two classes of moderate (II) and intensive (IV) classes, with the largest area covered by the moderate class (85.07 %) Sabzevar has a diverse variety of geomorphologic terrains from high mountains to Playa, and dividing it into two classes indicates the simplicity of the IMPDA in preparing desertification. The reason for this peculiarity is the diverse features, geometric mean and unbalanced classification. The mentioned hazard map along with key factors in desertification can be used by the related managers for combating desertification and moving towards sustainable development in Sabzevar.