Waterlogging risk assessment based on land use/cover change: a case study in Pudong New Area,Shanghai

Waterlogging induced by torrential rain or typhoon in urban areas due to rapid urban development and land cover changes has been a global hotspot and a potential risk affecting urban habitant lifelines and safety. This paper analyzed the impact of land use/cover change on the surface runoff and evaluated the waterlogging risk caused by precipitation with different intensities in Pudong New Area, Shanghai. A simplified urban waterlogging model has been built for the inundated water depth simulation through the combination of both SCS model and GIS spatial analysis with the consideration of underlying surface characters in urban area. Based on the simulated depth results, waterlogging risk ranks were further established to evaluate waterlogging risk of Pudong New Area under different conditions considering social survey results. The results show that the land use structure and pattern change increases surface runoff depth. Under the assumption of a daily maximum precipitation at 200 mm, the surface runoff depth increased by 13.19 mm from 1994 to 2006 due to urbanization. On the whole, Heqing, Huaxia tourism area, Chuansha, Tangzhen and Jichang Town have high waterlogging risk rank, Gaoqiao, Donggou, urban district, Jinqiao, Caolu, Sanlin and Beicai Town have medium waterlogging risk rank, and Zhangjiang, Gaodong and Huamu Town have low waterlogging risk rank. These results provide important information for the local government, and the method of waterlogging risk assessment can also be applied in other cities to provide guidance on waterlogging risk control.