Evolution of rain-flood characteristics and projection of future flood risk in Chongqing City
Urban flooding,exacerbated by the dual impacts of global climate change and rapid urbanization,poses a significant threat to the sustainable development of cities.Using hydrometeorological data from 1960 to 2019 in Chongqing and projections from ten global climate models from the Sixth Coupled Model Intercomparison Project(CMIP6),this study examines trends in extreme precipitation and regional flooding in the city.A large-scale VIC-Cama Flood coupled model was developed to simulate and forecast future climate,hydrology,and flood scenarios in Chongqing.The findings are as follows:①From 1960 to 2019,extreme precipitation in Chongqing showed an increasing trend,with growing variability in precipitation and discharge distribution.②The VIC-Cama Flood model,which is well-suited for the Upper Yangtze River,demonstrated good performance,with Nash efficiency coefficients of 0.81 for discharge simulations and 0.87 for water level simulations,and relative errors of 4.7%and 0.4%,respectively,across sub-basins.③Under future climate change scenarios,extreme precipitation in Chongqing is projected to increase significantly,with the annual cumulative precipitation exceeding the 99th percentile during the flood season increasing by 16.9%to 85.9%compared to the 1985-2014 period.Extreme hydrological events are expected to intensify,with the 50-year return period for maximum discharge and five-day maximum flood volume potentially shortening to less than 20 years under high-emission scenarios.④In the absence of water conservation projects,future climate change will exacerbate the risk of urban flooding.The cascading effects of extreme precipitation,cross-boundary flooding,and urban waterlogging under climate change will pose serious challenges to urban planning and sustainable development in Chongqing.
万方数据
维普
