Efficient Urban Flooding Management: A Multi-Physical-Process-Oriented Flood Modelling and Analysis Method

Flood models are essential for simulating and analysing urban flooding; however, accurately capturing the complex physical processes and their interactions remains challenging. This research introduces a multi-process flood modelling framework designed to generate realistic urban flood simulations. It integrates various hydrological and hydrodynamic processes through data-exchange synchronisation. A new surface flood control model (SFCM) was developed and applied in Huai’an District, China, using the storm water management model as its foundation. The SFCM was used to assess storm events, detect drainage outlets hindered by high river network water levels during extreme rainfall, and evaluate how river backflow affects drainage overflow and surface flooding. Results indicated that higher return periods of rainstorms reduced the number of drainage outlets obstructed by backwater, though backwater worsened surface flooding and drainage overflow. Compared to the current capacity of drainage outlets, using the maximum drainage capacity reduced the overflow rate of rainwater wells by 10.62% on average but increased river cross-section overflow by 1.72%. The average surface inundation area and maximum depth decreased by 0.78 km 2 and 0.05 m, respectively. This research introduces an innovative approach for simulating and analysing large-scale urban flooding, offering essential perspectives for urban planning and strategies to prevent flooding.