Hydrological Environmental Responses of LID and Approach for Rainfall Pattern Selection in Precipitation Data-Lacked Region

Global climate change and urbanization development have changed the hydrological environment dramatically. Flood control, non-point source pollution control, and comprehensive utilization of water resources are facing new challenges. On the basis of the Storm Water Management Model (SWMM), an approach for design rainfall pattern selection in precipitation data-lacked region containing model establishing, response analysis and design rainfall pattern screening was put forward. And the responses of the hydrologic, hydraulic and environmental of 2-commercial community mode are explored by using a simulation analysis under different rainfall patterns in this study. Based on the worst principle, the Chicago rainfall pattern was selected for the above-mentioned evaluation indexes at different reoccurrence periods. Results showed that, (1) in traditional development (TD), the values of surface runoff, peak flow and depth of outlet, and total pollution loading were at their maximum at the Chicago rainfall pattern; and in low-impact development (LID), the reduction rates of surface runoff and total pollution loading were at their minimum at the Huff4 rainfall pattern, and the reduction rate of peak flow was at its minimum at the P&C rainfall pattern; then design storm patterns at different simulation targets were obtained. (2) For the Chicago rainfall pattern, the reduction rates of various evaluation indexes decreased while the reoccurrence period increased, and the reduction rate of peak flow was more sensitive to high reoccurrence period rainfall than surface runoff. (3) After the setting of LID measures, the control effect of storm water and non-point source pollution gathered better results from the increase of permeable area and the change of microtopography, as well as from the physical and biological action. This study will provide a reference for the selection of design storm pattern at different simulation targets in regions with deficient rainfall data.