اولویت‌بندی پتانسیل سیل‌خیزی واحدهای هیدرولوژیکی با استفاده از GIS (مطالعه موردی: حوضه صفارود)

The sub watershed prioritization of flood generation and flood hazard zoning are a great help to identify and management of vulnerable flood area. Since the urban area of the city of Ramsar located at the end of watershed outlet, control and identify the areas of the flood generator has special importance. The purpose of this study is to determine the potential flood generation of different areas of watershed and map development of flood hazard zoning for each sub-watershed. To achieve this objective, the watershed area was divided into seven hydrologic units and then lithological units have been identified in this watershed. The slope of approximately 97% of the watershed is greater than 15% percent. About 62.23%
of the watershed has more than 45% vegetation. After determining the value of quantitative factors, flood potential were investigated with using Index-Overlay method in Geographic Information System (GIS) environment. Finally, Prioritization of Sub-basins was done with Lithological units, slope, land use and the percentage of vegetation cover. The results of this study showed that about 26.36 percentage of watershed area located in high potential flood generation and about 13.74 % located in very high potential flood generation area. The results of potential flood generation prioritization of sub-watershed showed that the Lot-Mohaleh’s sub-watershed with 5.41 % and the Javaherdeh’s sub-watershed with 80.39 % located in high and very high hazard zonal where they have the most and the least potential of flood generation in the Safarood watershed.