Sensitivity analysis of input parameters of SWMM model to urban runoff management (Case study: Mahdasht town)

During the past decades due to population growth and urbanization , urban runoff has increased and lead to different Environmental problems such as inundation risk, release the environmental pollutions and risks of flooding.Sensitivity analysis is used to determine the important input parameters which caused run off. Basically, the aim of this study was determine the important input parameters of SWMM model and the reliability of this model Performance in the Mahdashttown. Therefore, 10 parameters including percentage of impervious area, slope, width, N-Manning for impervious area, time of concentration, curve number, N-Manning for pervious area, depth of depression storage on impervious area, depth of depression storage on pervious area and percent of impervious area with no depression storage reduction, the first account of abovementioned parameters was increased and decreased 15 and 30 percent and flood peak discharge was selected as the dependent variable. For calibration and validation process model, corresponding to three event rainfall runoff measured at the output of the basin and was compared with runoff simulated by the model. The results showed there is good agreement between simulated and observed runoff discharge and depth.So this model can use to predict the inundation risk, design and prioritization areato fixing the inundation problem.