Spatial Prioritization of Land Degradation Using IMDPA Model with Emphasis on Wind Erosion and Climate (Case Study: Bordekhun Region of Boushehr)

Desertification and land degradation in arid، semi-arid and sub-humid dry regions، are a global environmental problem. Therefore، accurate assessment of desertification trend will be useful to prevent and eradicate these problems. The study area is located in Daiyer city of Boushehr province. In this study، in order to assess land degradation according to local conditions of the study area، two factors of wind erosion and climate were selected as the main factors affecting desertification. Assessment of desertification status in the study area was conducted on basis of these two factors and weighting indices according to the IMDPA model. After separating work units (Geomorphologic facies)، numerical value of each index was determined for each work unit، a data layer for each index was prepared and the layer related to each factor was specified by calculating the geometric mean of its indices score. Then، desertification intensity map was created by combination and determination of geometric mean of factors. The results indicated that 31. 74% of the studied area falls within the medium class، 62. 62% in the severe class and 4. 65% in very severe desertification intensity class. Work units 6 and 8 with maximum quantitative values were placed in first priority of degradation. The work units 9، 13، 12، 10، 14، 15، 2، 7، 4، 3، 1، 11 and 5 with minimum quantitative values had lower priorities، respectively. Among the studied indices، two indices of dryness and non- living cover density percentage were the most important factors causing the desertification in this region.