海绵措施下降雨径流模拟及污染物削减率评价OACSTPCD

[Objective]In order to explore the effect of sponge measures on rainfall runoff reduction and pollutant reduction capac-ity,the 23 km2 sponge pilot area in Guyuan City was taken as the research object to simulate the variation of rainfall runoff and pollutants before and after the implementation of sponge measures under different return periods.[Methods]Using high-precision terrain and GPU acceleration technology,a hydrological and hydrodynamic model suitable for flood simulation in Guyuan City was constructed.[Results]The result showed that:(1)Under different rainfall scenarios,after the implementation of sponge meas-ures,the annual runoff control rate increased by 16％～20％,and the pollutant reduction rate was about 98％.(2)Rainfall pat-tern has a significant effect on the total runoff control rate.When the rainfall is small,most of the rainfall is left in the local area.(3)The simulation result of the model provide guidance for the arrangement of sponge measures.It is suggested to set up grassed ditches and seepage wells beside the road in No.2 water accumulation point,so as to reduce the amount of water flow from the main road to this place.No.3 water accumulation point is recommended to improve the drainage pipe network;No.6 water accu-mulation point is recommended to set up grass planting ditch and retention pond;No.10 water accumulation point is recommen-ded to set up ecological grass planting ditch and permeable pavement on the main road on the west side.[Conclusion]A flood model suitable for Guyuan City is constructed,which can realize the simulation of rainfall runoff and pollutant reduction rate by sponge measures arrangement,and provide a scientific basis for urban stormwater management and urban planning.