Assessing Economic Loss from Urban Waterlogging in Beijing under Climate Change Using a Hydraulic Model

Long-term climate change has amplified the frequency of extreme climate events, such as intense short-duration heavy rainfall, which has increased the risk of urban waterlogging. The severe economic losses that result warrant serious attention, but accurately quantifying such economic losses remains a significant challenge. In this study, a climate change-adapted economic loss evaluation framework is established for urban waterlogging using a hydraulic model with coupled model intercomparison project phase 6 (CMIP6) scenarios. Choosing Beijing as a case study, based on shared socioeconomic pathways (SSP) and representative concentration pathways (RCP), we formulate three future climate scenarios (SSP2-RCP4.5, SSP3-RCP7.0, and SSP5-RCP8.5) using CMIP6 data. Next, we simulate the urban waterlogging risk under each climate scenario with four return period subscenarios employing the InfoWorks integrated catchment management (InfoWorks ICM) model. We develop waterlogging loss rate functions for four distinct land-use types in Beijing. Finally, we quantify the waterlogging losses caused by climate change in Beijing. We find that urban waterlogging impacts an extensive area of 199 million m(2), or 26.05% of the study region, and causes maximum economic losses estimated at 29.78 billion yuan for a 100 year recurrence period under the SSP5-RCP8.5 scenario. The largest economic losses are observed for residential land use, closely followed by commercial land use. By offering a method of quantifying the urban waterlogging economic losses arising from climate change, this study aids the implementation of effective urban waterlogging risk-management strategies.