Effective Evaluation of Infiltration and Storage Measures in Sponge City Construction: A Case Study of Fenghuang City

In recent years, urban waterlogging problems have become more and more serious, which has led to flood disasters in some cities. The Chinese government launched the sponge city pilot construction in 2015 to mitigate the risk of urban flooding and control the runoff in source areas. Rain-runoff control is one of the main indices of a sponge city, thus, evaluating its control effect is essential for sponge city construction. This paper chose Fenghuang city, located in the west of Hunan province, as a case study area to assess the rainwater control effect by using the MIKE FLOOD model. The results showed that: (1) the total annual runoff control rate (TARCR) of sponge city design was a reasonable indicator for daily rainwater control; (2) the goal of Fenghuang Sponge City was close to the 1-year rainfall event; and (3) infiltration and storage measures could reduce but not eliminate urban waterlogging. The capacity of the drainage system should be fundamentally improved to enhance the prevention standards of urban waterlogging.