Study On Rainwater Joint Operation Scheme In Qingshan Lake Area Of Nanchang Based On SWMM

In recent years, the frequency of heavy rains is increased in many places. Existing urban drainage capacity can not discharge the rainwater to the receiving water body in a short time. The city produced a large area of water, leading to the phenomenon of urban waterlogging. Using the existing technology to establish an effective model of rainwater in the city, it has a strong practical significance. By analyzing the rainwater characteristics of Qingshan Lake area in Nanchang, use SWMM to establish the stormwater management model of Qingshan Lake area in Nanchang. Simultaneously, we consider the drainage pump station of Qingshan Lake to obtain rainwater joint operation scheme of Qingshan Lake area in Nanchang. The main contents are as follows:(1) It summarized model theory and modeling steps of SWMM, the model of study area was established. Combined with Qingshan Lake area survey, by generalized drainage network, created the background of model, divided the sub-catchment area, estimated the parameters of model, the model was established.(2) The parameter of stormwater management model was calibrated. Finally, the model of Qingshan Lake area in Nanchang was validated. We selected 2 representative rainstorm processes to calibrate parameters. We selected 1 representative rainstorm process to verify the model. Finally, the model was validated.(3) Under different rainfall scenarios, we used the model of Qingshan Lake area in Nanchang to simulate the existing drainage system. The results showed that, when the return period was 0.5a, 1a, 2a, Qingshan Lake Area were not appear serious waterlogging water phenomenon, when the return period was 5a, 10 a, many nodes occured severe flooding, and many pipes ran at full status.(4) According to the analysis of the performance of the drainage network at the design rainfall situation, and the drainage pump station of Qingshan Lake, we got rainwater joint operation scheme of Qingshan Lake area in Nanchang. The return period is 0.5a, 1a. We need to control the water level to be 17.77 m, 17.67 m. They are higher than the normal water level, 17.50 m, it meet the requirements. The return period is 2a, 5a, 10 a. We need to control the water level to be 17.47 m, 17.33 m, 17.20 m. They are lower than normal water level, 17.50 m. At this point we need to adjust the pumping station of the Qingshan Lake, in order to avoid the occurrence of waterlogging.(5) We discussed measures to improve drainage system capabilities of Qingshan Lake area on the LID concept. According to the actual situation of Qingshan Lake area in Nanchang, the feasibility of LID measures in the area of using were assessed. We developed the layout principles and the principle of selection of LED measures. Combined with rainwater simulation results of the model, we proposed reconstruction measures for common land types.