Hydrodynamic simulation and risk evolution of urban waterlogging based on integrated SWMM–LISFLOOD modeling: a case study of Dongxihu District, Wuhan

Abstract

Rapid urbanization has altered rainfall–runoff processes in many cities and increased the hydraulic burden on urban drainage systems during short-duration, high-intensity storms. Taking a representative drainage system in Dongxihu District, Wuhan, as a case study, this study investigates urban waterlogging under a 20-year return-period design storm. An integrated 1D–2D hydrodynamic framework was established using EPA-SWMM and LISFLOOD-FP. SWMM was used to simulate rainfall–runoff generation and drainage-network routing, while node-overflow hydrographs were transferred to LISFLOOD-FP to simulate subsequent surface inundation. The SWMM model comprised 869 nodes, 890 conduits, and 845 sub-catchments. A 2-h Chicago design storm with a 5-min rainfall-input interval was adopted. Under the 20-year design storm, 96 drainage nodes overflowed, accounting for 11.05% of all modeled nodes. The cumulative overflow volume reached 12.84 × 10 4 m 3 , and the maximum continuous overflow duration was 2.18 h. Major inundation zones were concentrated near Linkonggang Avenue, Wuhuan Road, Jinyintan Avenue, and the Taxi Road–Fushan Avenue section, with simulated maximum inundation depths ranging from 0.32 to 0.48 m at representative road sections. The spatial pattern of waterlogging reflects the combined effects of runoff generation, local drainage-capacity limitations, and downstream hydraulic constraints. Because continuous observations of surface-water depth and drainage-network hydraulics were unavailable, the results should be interpreted primarily as scenario-based identification of waterlogging hotspots rather than as fully field-validated hydraulic predictions.