Mapping the Flood Inundation Area for Climate Adaptation Planning: A Chinese Case in Xinxiang City, Henan Province China

With global warming, rising sea levels, and more frequent extreme rainfall events, the need for rainstorm-flood climate adaptation planning has become more urgent. At present, there are relatively few planning studies from the perspective of rain-flood climate adaptation in China. In this study, the Sentinel-1 Multi-Temporal Synthetic Aperture Radar (SAR) was used to extract the urban flooded area from the extreme rainfall weather caused by storm surges. Rainstorm floods generally occur in cloudy and rainy weather, and there are a lot of clouds blocking the use of optical remote sensing images, which cannot effectively monitor the flooded area. However, Synthetic Aperture Radar (SAR) can penetrate the clouds and obtain optical high-resolution radar images, which can be observed all day long. This method is used to identify the spatial distribution of the risk of extreme rainfall caused by storm surges in Guangzhou. The significance of this study is as follows: (1) Based on data-driven, it provides an operable technical process and method for rainwater hazard mapping of climate adaptability planning of megacities in China, which can be applied to rainwater hazard mapping of other cities and enhance the science of decision-making. (2) By mapping the flood probability, we can effectively identify the spatial differentiation characteristics of the flood risk, so as the characteristics of sensitive groups and environment, and provide a reference for the spatial layout of emergency disaster reduction and prevention facilities to strengthen urban adaptability.