Assessment of Factors Affecting Water Erosion Based on Quantitative Geomorphology Model (Case Study: Zonouz Chai watershed)

Before modeling the estimation of erosion and sedimention in order to select suitable criteria and indices، it is necessary to analyze factors affecting erosion. Based on the quantitative geomorphology model developed by the national specialists، the Analytical Hierarchy Process (AHP) was used to conduct the quantitative measurements of parameters affecting erosion. According to geomorphology، the hierarchical tree was developed consisting of six criteria: land cover، pedology، topography، land use، climate، geology، as well as ten indices: percentage of vegetation، growth forms، soil texture، permeability، slope، aspect، land use، type of precipitation، annual average precipitation، and lithology. When the weight and importance of each criterion and indeces were determined، the factors affecting erosion in Zonouz chai watershed were prioritized and the weighted erosion rate map was developed. Finally، it was determined that as compared to other factors، pedology and land cover had the priority weight by 0. 896 and 0. 51، respectively، in terms of impact on erosivity of Zanoz Chai watershed.