Evaluation of impacts of the establishment of detention dams in flood management (Case study of the Kan River basin)

The occurrence of flood usually associated with huge losses of life and property, and flood control actions due to the extent of aquiverous basins and multiplicity of areas at risk, requires a large budget. Therefore, proper management and beforehand actions are an undeniable necessity. Kan areas due to the special features such as location and as a place of recreation for people are important for flood control realization projects. In this study, flood routing with different return periods in the basin area of Kan was done using HEC-HMS software. According to physiographic conditions of basin, number of four delay dam in the four output under basin were designed and their effect on routing and outflow hydrograph specifications of basin were analyzed. Peak flow rate of basin output as a result of establishing delay dams, showed a significant decrease so that the flood peak discharge for return periods of 2, 5, 10, 25, 50 and 100 years have been obtained respectively from 76.60 to 78.0 - from 79.4 to 51.4 - from 39.1 to 33.7 percent. Also, by increasing the return period of flood the effect of these reservoirs in reducing flood outflow is reduced

Keywords:

flood control , Kan basin , detention dams , HEC-HMS