Siting Detention Basins Using SWMM and Spatial Multi-Criteria Decision Making

Abstract

Detention basins are one of the structural measures for floodwater control in urban environments. They are effective tools in flood mitigation, but some studies have shown that they may aggravate the condition if not properly sited. This study presents an innovative approach which directly incorporates hydrologic-hydraulic modeling results to the site selection procedure for flood control detention basins. Darakeh Catchment located in Tehran is selected as the case study. Hydrologic, physiographic, and economic parameters are considered as siting criteria. SWMM model is employed for simulating hydrologic-hydraulic processes and evaluating the current drainage network against low-frequent storms. Modeling results, including flooded junctions and the flow hydrographs, are used as input parameters to the spatial decision making framework. The framework employs Analytical Hierarchy Process (AHP) as the decision making structure and geographic information system (GIS) as the spatial analyst tool. The output is a raster map which shows each cell potential for the placement of the detention basin. The proposed approach aims to improve the siting procedure based on these measures and other BMPs in an urban environment