The Effects of Land Use Optimization on Soil Erosion Reduction and Increased Benefits of Catchments, Case study: Zakherd catchment, Fars Province

Improper use of land has led to gradual erosion and degradation, reduction of crop products as well as decreased benefits of agricultural areas and rangelands. Therefore, planning for proper use of the land based on its capability and land use optimization is an important and major solution in soil conservation practices. The main purpose of this research was to determine optimum area of each land use in order to decrease soil erosion while to increase income in Zakherd catchments. The study area is located in Fars province, Iran. First, land use map of the region was prepared based on Land sat satellite images and field studies. Then, the rate of soil erosion was predicted by implementing MPSIAC model. Meanwhile, the net income for each land use was calculated separately. After characterization of limits and objective functions in the study area, optimization area for each land use was obtained by using multi-objective linear programming. The obtained results revealed decrease of dry and irrigated farming and increase of orchards and rang lands in the optimum condition. It means that orchards and rang lands area increased up to 212.87% and 303.26%, respectively while dry and irrigated farming area decreased to 65.02% and 57.55%, respectively. Also, the results indicated that land use optimization could reduce soil erosion rate in the study area up to 13.16% whereas the benefits were increased at rate of 27.04%. The results of sensitivity analysis of the model parameters showed that any change in the area of orchards and dry lands farming will have the most impact on the benefits and soil erosion change of the studied catchments.