Zoning and morphological analysis of floods of Dinevar river (Kermanshah province) with using HEC-RAS hydrodynamic model

Floods are the most common natural hazards, the recurrence of which is increasing and the associated risks in urban and rural areas are of global importance, although their importance is not well understood for developing countries. The aim of this study was to zoning the flood risk of Dinevar River in Kermanshah province. Therefore, the HEC_RAS numerical model was used to simulate the flood and was used through the HEC-GEORAS. Using SMADA software, the peak flow rate was calculated and the flood zone with different return periods of 2 years, 10 years, 25, 50, 100 and 200 years is simulated area and with the help of digital depth model Water and land use layer, the amount of damage was calculated using the equation of depth function and damage in the return period of 25 years, 50 and 100 years. The results of this study show that the area of flood expansion zone in the return period of 25 years is 40.34 square kilometers, in the return period of 50 years is 43.51 and in the return period of 100 years, 44.28 square kilometers is endangered in terms of damage. 25 years is considered a baseline flood that shows significant damage, covering all farms, but floods affect parts of farms at lower returns. But it is controllable, while 25-, 50-, and 100-year-old floods have completely endangered many rural centers and farms. 50 years has been an average of 85% more, which requires flood control for sustainable management.