Flood Susceptibility assessments Using Frequency Ratio model in Talar Watershed

Flood can be having devastating effects on watersheds and human life, so, recognize of flood prone areas have a high influences on flood management. The aim of this study is to assessment of flood susceptibility at Talar watershed with an area of 2067 square kilometers. For this purpose some flood conditioning factor such as elevation, land slope, curvature, topographic wetness index, stream power index, average rainfall, distance to the river, hydrologic group of soil, maximum depth of soil, and land-use have been used. Flood conditioning factor have been prepared using related software and then converted to raster format. In the next step the 135 flood location in the study area were determined. These flood location were divided into two groups consisting of 93 locations for calibration and 42 locations, for validation. Then with comparatively analysis between previous floods coordinates and impressive environmental parameters on flood occurrence the probability of flooding for each class of each parameter was calculated. Faunally was obtained the flood risk map of the study area. Based on the flood risk map, the territory was divided to 5 class sensitivity, very high, high, medium, low and very little. The results have been showed that the frequency ratio method with 80% accuracy have high performance in determination of flood prone areas in Talar watershed.