EFFECT ASSESSMENT OF SPONGE CITY CONSTRUCTION IN THE INTERNATIONAL ECO-BUSINESS DISTRICT IN SONGJIANG DISTRICT IN SHANGHAI BASED ON SWMM

The construction of the sponge city is aimed to restore the natural storage capacity of the city and improve the ecological environment and urban resilience. In this paper, the SWMM of international eco-business district in Songjiang district in Shanghai was established to evaluate the effect of sponge city construction on regional runoff control and pollution load control. The results showed that: compared with the traditional development mode, the construction of sponge city could significantly store rainfall, then reduce regional runoff, also reduce the pollution load into the river, and effectively reduce the pressure of regional drainage and water environment. The total runoff of sponge city was reduced by 40.8%, 39.5%, 37.0% and 35.8%, respectively, after 2 hours rainfall with recurrence period of 3-year, 5-year, 20-year and 50-year. The reduction of TSS, COD, TN and TP was 36.3%, 39.4%, 32.9% and 47.6%, respectively, after 2 hours rainfall with 5-year recurrence period.