Analysis of Urban Flood Simulation Considering Dual-Drainage and Buildings

The frequency of urban flooding has increased owing to the increasing occurrence of extreme weather events driven by climate change. According to the Shared Socioeconomic Pathways (SSP) scenarios, the temperature and precipitation levels in the Korean Peninsula are expected to increase, resulting in more frequent and intense localized heavy rainfall and hydrological disasters. This necessitates nonstructural measures to reduce urban flooding. This study empirically examined the role of buildings and dual drainage in urban flood modeling, while comparing the effects of various modeling approaches on flood forecasting and risk evaluation. Using the manhole overflow data derived from the Storm Water Management Model (SWMM) model, a 2D flood analysis model was applied. Additionally, a fully coupled 1D-2D model (H12) incorporating dual drainage concepts through grate inlets was used to improve the accuracy of urban flood prediction and facilitate comparative analysis. The findings revealed that incorporating dual drainage and building structures significantly improved the accuracy of urban flood simulations, emphasizing their importance in enhancing the reliability of urban flood forecasting systems.