Analysis and Monitoring Model of Rainstorm: Flood Disasters in Shanghai

Under the background of global climate change and rapid urbanization, Shanghai, as a typical coastal megacity, faces the double threat of frequent extreme weather events and sea level rise. This study analyzes the complex causes of rainstorms and floods in Shanghai through a multi-dimensional approach, including the superposition of natural factors (monsoon climate, low-lying topography, tidal action) and human factors (hardening of the subsoil, development of underground space, and heat island effect), as well as the synergistic effect of sea level rise and storm surges, jointly exacerbate the risk of flooding in the city. The study integrates the use of numerical meteorological models (e.g., ECMWF, D-Flow), remote sensing observations (Sentinel-1, MODIS), and distributed hydrological models (TOPKAPI, Liuxihe), combined with parameter sensitivity analysis and multi-model coupling techniques, to quantify the coupling mechanisms of extreme precipitation, storm surge, and urban hydrological response. The results show that the intensity and frequency of extreme precipitation are increasing significantly, and the design standard of urban drainage system is lagging behind the speed of climate change; the existing models have limitations in the simulation of extreme events, dynamic calibration of parameters, and multi-hazard superposition analysis. The study suggests that in the future, it is necessary to develop high-resolution meteorological-hydrological coupled models, integrate remote sensing data to optimize parameter estimation, strengthen climate change adaptation research, and promote multidisciplinary collaboration to build an intelligent early warning system, so as to provide scientific support for the resilient development of Shanghai and similar cities.