A Coupled Hydrodynamic and Rainfall-tracking Model for Source-to-impact Analysis in Urban Inundation

Urban inundation is becoming increasingly severe as a result of climate change and rapid urbanization. Various urban water management practices are designed to alleviate urban inundation hazards. It is essential to better understand and model the dynamic process of surface runoff to inform the arrangement of effective strategies for urban stormwater management. A coupled hydrodynamic and rainfall-tracking model is proposed to determine spatial prioritization by identifying distributions of source areas and quantifying the contribution rate for source areas to inundating areas. Specially, the rainfall mark variable (R) is developed to trace out the pathway of runoff generated by rainfall in the proposed modeling. The coupled model is successfully validated against two idealized test cases including dissymmetric V-shaped and V-shaped catchments. Indeed, the Jinhua underpass catchment area reveals its capability in representing detailed hydrodynamic information and obtaining contribution rates of source areas to inundated areas. The approach can help recognize opportunities to determine the spatial prioritization and adaptability for city planners to complete the optimal solution schemes between the available resources and alleviating inundation.