A Coupled River Basin-Urban Hydrological Model (DRIVE-Urban) for Real-Time Urban Flood Modeling

Reliable urban flood modeling is highly demanded in emergency response, risk management, and urban planning related to urban flooding. In this paper, the Storm Water Management Model (SWMM) is adapted to simulate urban rainfall-runoff and pipe drainage processes within the Dominant river tracing-Routing Integrated with VIC Environment (DRIVE) model which accounts for natural river basin runoff generation and routing processes. The integrated DRIVE-SWMM model (referred to as DRIVE-Urban) allows to explicitly delineate the mass-energy interactions between urban drainage system (e.g., pipes and dikes) and river networks. This presents a further step model development for accurate urban flooding prediction which is lacking in existing urban flood models and traditional hydrological models. The validity of the DRIVE-Urban model is evaluated for three case studies in Haikou City, China, with camera observations of street inundation during typhoon landfalls and heavy rainfall events. The results show that the DRIVE-Urban model successfully captures 62%, 69%, and 77% of the total observed inundated road-sections for the three cases respectively. The third case study with severe flooding situation shows that the DRIVE-Urban performance is further improved when given reliable river and tidal level information, indicating the importance of integrating river-basin with urban hydrological and hydraulic modeling.