An Integrated Methodology for Assessment and Mapping of Land Degradation Risk in Markazi Province, Iran

Desertification is recognized as a serious environmental threat in Iran because of its climatic-geomorphologic conditions. Desertification and land degradation in arid, semi-arid, and dry sub-humid regions, is a global environmental problem. Accurate assessment of the status and trend of desertification is instrumental in developing global strategies to prevent and reverse this problem. The goal of the present study was to discover and introduce criteria and quantitative indices and test modeling to monitor and assess desertification in the ecosystems of Iran. Past research has shown that effective factors for desertification can be categorized into nine groups of criteria. For each criterion is typified by a group of indices. All indices have been adjusted to natural conditions in Iran and their qualification is based on expert knowledge and the range of natural occurrence. The Iranian model of desertification potential assessment (IMDPA) was used to evaluate desertification risk in the Farasman region in central Iran. The results show that, in spite of common techniques, the proposed method has the best accuracy and produces precise results. The data were integrated over a regional geographic setting using a GIS, which facilitated data display and the development and exploration of data relationships, including manipulation and simulation testing. Results show that about 77% of the area fell into the moderate category, 15% fell into the low category, and the rest (8%) fell into the high category for desertification risk. It was found that the overall severity of land degradation and desertification in the study area has increased during the last two decades with highly and moderately degraded land accounting for 77% of the total area in 2010. The incorporation of natural and anthropogenic factors into the analysis provided a realistic assessment of the risk of desertification.