摘要
The impacts of floods on human society are expected to increase at both global and regional scale in the context of global climate change and increasing human activity in flood-prone areas. However, spatially explicit and dynamic assessments of flood exposure in China are still very limited, which hinders the development of risk-based flood management considering dynamic changes. Therefore, this study explored the spatial-temporal variations of flood exposure in China from 1992 to 2020 through flood susceptibility mapping and using satellite-based nighttime light data. It can be revealed that a significantly high level and rapid increase of flood exposure could be observed in China, especially around some major metropolitan areas in the eastern region. The expansion of flood exposure was mainly distributed in North China and some coastal areas during 1992-2000; while mainly occurring in South China during 2000-2013, especially in middle Yangtze River basin where flood susceptibility is highest. The changes of flood exposure in China were mainly driven by the increase in the number of lit pixels during the early period, and were dominated by the increase in the intensity of lit pixels in the later period. This process continued to the latest period of 2014-2020. This implies that upgrading of existing flood management facilities and efforts for more effective measures are urgently needed in flood-prone urban areas with increasing exposure intensity. In addition, this study demonstrated the advantage of nighttime light data for disaster assessment and monitoring. With the development of more nighttime light products of higher resolution and higher detection ability and the integration with ground-based observation, it is promising to achieve more precise monitoring and analysis of flood exposure at a large scale, and support fine-grained management of flood risk.
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单位武汉大学