Ecology, Environment and Conservation Paper

SUB-BASIN PARTICIPATION IN FLOOD PRODUCING OF BASIN

Babak Sanahmadi, Maaroof Siosemarde and Saeid Shabanlou

Abstract

Flood is often called a phenomenon that leaves harmful effects by submerging lands and coastal areas. Flood control is in fact said to all preparations and methods that lead to reduction of the harmful effects of a flood. Since Gorgan River basin is prone to flooding, identifying areas prone to flooding is essential. The present study is a way of using hydrology model and flood risk prone areas within watershed and determining these verities of floods, i.e. to prioritize the rise in each sub-basin or hydrologic units. First, the watershed in GIS environment (GIS) software using Arc- Hydro basin was divided into nine areas, then the physical properties of basins and sub-basins was determined. With data required for flood hydrographs design for each sub-basin and watershed through the implementation of the entire HEC-HMS model was obtained. With peak discharge under consideration based on watershed and flood index definition for the rise in this research, it is proposed in each model run the efficacy of each sub-basin is removed from the flood routing of basin process and the amount of basin output discharge without participation of the corresponding sub-basin was calculated. In this respect among sub-basins in terms of impact on the flood basin outflow, sub-basin No.W 150 is more critical.