An Efficiency Comparison of the IMDPA and ESAs Models on Desertification Risk Management in Arid regions of Southern Khorasan Razavi, Iran

The purpose of this study was to compare the efficiency of two models of IMDPA and ESAs in assessing the intensity of desertification in the drylands of southern Khorasan Razavi province and management based on the best-performed model. For each geomorphological unit, initial data was first collected, and Criteria and indices of the models according to regional conditions, were then scored and intensity of desertification calculated. This was then followed by assessing the risk of desertification from the combination of hazard intensity, elements at risk and environmental vulnerability data. Maps were then verified and validated against ground control points, using Chi-square test and Kappa index. The results showed that based on the IMDPA model, the most intensified area of desertification in the region with 54.7% frequency was the highest area with severe desertification intensity with distribution with the climate and vegetation criteria appeared to be the most controlling factors. In the ESAs, desertification intensity was classified into three classes, with the highest area of the second-class critical class with a frequency distribution of 79%, and the climate and wind erosion rates had the highest impact. This emphasizes that the impact of natural factors on the desertification process in this region. Therefore, based on field studies, expert opinion and Kappa index of 0.897, the ESAs model was selected as the most appropriate model. Risk assessment results show that more than 51.5% of the environmental elements, located mainly in the central and southern parts of the region, are at moderate to very severe risk of desertification, which can generate annual damages of IRR 7.6 billion. Therefore, the implementation of suitable programs for combating desertification in the studied area can reduce this damage and its costs.