Comprehensive flood risk assessment of urban flooding based on the 1D/2D coupled hydrodynamic model

Abstract

In urban environments, urban flooding can lead to significant economic losses due to high population density and valuable economic properties. The complexity of urban flood disasters and the diverse entities affected present substantial challenges for accurate flood risk assessment. In response to this critical need, we have developed a comprehensive urban flood risk assessment method that evaluates the flood risk for primary affected entities, including residents' lives, ground buildings, and underground spaces. This proposed assessment method is based on both scenario analysis and the index system method. Initially, it predicts the disaster-causing hydraulic characteristics, such as water depth, flow velocity, and building inundation, using a high-performance 1D/2D coupled urban flood hydrodynamic model. Subsequently, it assesses the flood risk of disaster-affected objects, such as people, ground buildings, and underground spaces, based on hazard, vulnerability, and exposure indices. We successfully applied this comprehensive urban flood risk assessment method to a highly developed urban area in Wuhan City, China. To address the challenge of data acquisition, we utilized web crawling to gather information on industrial distribution, property prices, and shop rents to support flood risk analysis. The flooding process and corresponding risk levels of primarily affected objects under different rainfall return period scenarios were comprehensively evaluated. The established model can serve as a reference for disaster prevention and reduction technologies for other cities threatened by urban flood disasters.