Flood Risk Mapping and Evaluation by using the Analytic Network Process Case Study: (Khiav Chai Catchment)

Flood is one of the most common natural worldwide hazards that causes enormous losses of life and property throughout the world. Therefore, the development of flood mapping forecast models is curial in decision making before the flood and for the after flood management. The aim of this study is to determine the flood hazard zones in the khiav Chai basin using the network analysis process. To implement this model in the area under study, various data such as rainfall, land use, slope-morphological characteristics such as convexity (profile curvature) convergence divergence slopes (plan curvature), steep slopes, vegetation index (NDVI), distance from major rivers and drainage network density were considered. The results obtained from the network Analyzer model shows the fact that more than 15 percent of the area affected by the floods with very high potential risk of occurrence are mainly located at the bottom of the basin. These levels are often less than 35% in slope, with low vegetation density profiles, converged areas with concave surfaces, and areas near rivers. Analysis of the final weights derived from the AHP in relation to flood risk shows that the slope of the geological formations operating by 0/99, and 0/822 value, have the highest impact and influence, regarding the high degree of control and influence they have on the amount of runoff and discharge of the surface area. The importance and influence of the SPI with 0/226 and 0/065 STI are of less important compared to other factors.