The Optimal Location and Dimensions of Flood Control Detention Dams at Kan River Basin, Tehran, Iran

Detention dams are one of the structures used to deal with the destructive effects of floods, especially in mountainous rivers. These structures control the discharge of surface water flowing into or down a "dry watercourse" in a storm so the discharge can be carried by the waterway. These structures not only affect the peak discharge, but also increase the travel time. Based on "Integrated Flood Management", the impact of a set of measures should be considered together. Therefore in this study, the location and dimensions of several detention dams in the extent of Kan basin are determined simultaneously in an integrated approach. For this purpose, multi-objective harmony search algorithm (NSHS) is used to determine the location and dimensions of these structures by minimizing the initial cost and outflow peak discharge as objective functions. The results of this study show that using only two detention dams, the peak discharge is reduced by 64.44%, while the use of these structures, in almost all sub-basins (seven sub-basins), reduces the peak discharge by only 9.7%.