Prioritize the sub basins to watershed management activities (Case study: Watershed Daryan of Semnan province)

The first condition for control erosion and improve of watershed with critical status, identify and prioritize areas and catchments with a critical situation. At the time of control activities implementation, this action causes, more considered higher priority areas and conservation programs focus on such areas. The purpose of this research is priorities for watershed management sub basins of Daryan watershed, using similarity to ideal option (TOPSIS) method. First, in this study, six criteria (population, average production, water resources, agricultural land surface, erosion and formation) to prioritize is selection, and then the weight of each criterion using entropy method was determined. Among the criteria studied population and erosion were the highest and lowest weight respectively. The results showed that among the 38 sub-basins studied, sub basin A10, A’11 and B’7_A’12_C’21 because of high-ranking criteria of population, water resources and agriculture have the highest priority and sub basin C6, C9 and C’7 due to the lower these criteria the lowest priority given to the watershed.