Simulation and Evaluation of Rainwater Runoff Control, Collection, and Utilization for Sponge City Reconstruction in an Urban Residential Community

Abstract

Residential areas are important for the underlying surface of a city, and the sponge construction of a residential area is a key topic in sponge city construction. Taking the Zi-Jing community as the research case, the SWMM model was established for simulation, and the rainwater runoff control, collection, and utilization were compared and analyzed before and after the implementation of sponge transformation for the designed rainfall conditions of once in 3, 5, 10, 20, and 50 years. The results showed that the water depth of the four outlet pipes was not a full tube at the first peak time. The full duration time was reduced to 1–5 h at the second peak, and the flow reduction rate at the pipe outlet was between 30% and 100%. The water storage of sub-catchments A1, A3, and A4 increased significantly and continued to increase after the peak rainfall occurred, while that of A2 decreased significantly after the transformation after the transformation. For the whole residential area, the surface runoff decreased by 37–47%, while the surface water storage and infiltration increased by 8–14% and 23–39% respectively after reconstruction. The direct storage volume of rainwater in the four sub-catchment areas was filled at least once above a once in 5 years scenario. The main conclusions were as follows: Sponge transformation in residential areas with 17.46% sunken greenbelt and 40.85% permeable pavement, and the time of the pipe outlet in full status can be shortened by 30–200 min in different rainfall return periods. With the increase in the rainfall return period, the improvement range of the infiltration increased from 23.36% to 39.54%, the improvement range of the storage capacity for rainwater decreased from 14.36% to 8.06%, and the reduction degree of surface runoff increased from 37.73% to 47.43%. The water consumption for flushing is about 30 m3 per day for 1000 people, and the rainwater storage volume of 765 m3 in this study can meet the flushing water demand of 5000 residents in the community for 3–5 days.

Operation Risk Simulation and Interaction Impact of Stormwater and Sewage Systems Based on Storm Water Management Model

“…Figures 2 and 3 display the land use and DEM data. The one-dimensional hydraulic model of the pipe network is constructed using the stormwater pipe and combined sewer pipe data from Figure 1 [33,34]. The generalized model comprises 10,191 stormwater pipes, 10,014 stormwater nodes, and 415 outlets, along with 117 combined sewer pipes and 117 combined sewer nodes.…”

Simulation and Comprehensive Evaluation of the Multidimensional Environmental Benefits of Sponge Cities

“…According to the actual situation, the Horton model was selected for the infiltration simulation model [62], the saturation function was selected for the accumulation model, and exponential flushing was selected for the flushing model.…”

Simulation and Comprehensive Evaluation of the Multidimensional Environmental Benefits of Sponge Cities

“…The average slope of the sub-catchment area is 1.7%, which is calculated from the DEM data of all nodes; the pipe diameter, pipe length and slope are obtained from the pipe network data. According to the actual situation, the Horton model was selected for the infiltration simulation model [56], the saturation function was selected for the accumulation model, and exponential flushing was selected for the flushing model. Model calibration and validation were performed using the data for the eight actual monitored rainfall sites listed in Table 3, where the initial calibration (sensitivity-based radio tuning calibration) was performed using the SRTC tool in PCSWMM [57], followed by more accurate calibration via the availability-aware scheduling algorithm by using the nondominated sorting genetic algorithm II (NSGAII) [58].…”