Flood Hazard Zonation in the Aghlaghan Chay Watershed Using by ANP Model

Flood is one of the natural disasters in mountainous area. Recognition of susceptible areas for happening flood is also one of the main steps in natural resources management and development planning. Aghlaghan chay watershed due to the existing condition in the area, such as topography and continental issues, is very susceptible for flood formation which causes happing so many damages to rural habitation, farms and ways of communication. The occurring of this phenomenone with increase erosion of soil and loss of valuable resources of it, causes to increase in filling the cistern of Yamchi Dam. Therefore, the purpose of this study is area paitition of the area interms of potential of the flood happening. In this study, first whit field investigation and studying of resources, nine factors are recognized as the effective factors for making and happening flood. These factors are: slope, aspect, lithology, elevation, rainfall, temperature, landuse, distance from drainage and use of soil. Then informational layers are provided in Geographical Information System (GIS). Valuation and standardization of maps are conjoined with the use of the Fuzzy method. For overall weight factor, we used (ANP) models. Finally, the obtained map is classified in five categories from very low to very high risk. According to the results, the factors like: Slope, lithology and soil have the most effect on happening flood in Aghlaghan chay basin. Also According to the catchment map, risk of happening flood exists respectively from 18 and 22 percent of the area of watershed from very high risk class to high risk class. All in all, the results of the study show that the Aghlaghan chay basin has very high potential in terms of happening flood, so accomplishment of conservation, watershed and management works and steps in the area of study is important and necessary.