Department of Geoinformatics, School of Natural Resource Management, Central University of Jharkhand, Ranchi, 835222, India.
Environ Monit Assess. 2022 May 5;194(6):402. doi: 10.1007/s10661-022-10076-x.
Floods in urban areas result in a detrimental impact on the natural environment and human health and pose major risks to assets and communication systems. In cities with high population density, the magnitude of flood damage largely depends upon flood inundation as well as floodwater depths. The present study compared recent flood inundation extent, damages caused, and possible floodwater depth in two highly developed metropolises of China and Japan, i.e., Wuhan and Kumamoto cities, for the year 2020. Sentinel-1 satellite data-driven change detection algorithm in Google Earth Engine (GEE) was applied to identify potentially flooded regions. Major land use land cover classes such as urban areas and croplands affected by the flood were mapped in conjunction with the exposed population. ALOS PALSAR digital elevation model (DEM) was used to study the inundation depth. The study revealed that 322 km of the area has been inundated by floodwater in Wuhan city with 230 km and 140 km areas under damaged croplands and urban regions. Around 817,095 people were exposed to this natural catastrophe in Wuhan. The city Kumamoto has witnessed an inundation area of about 505 km with damaged cropland of 350 km and an urban area of 83 km.
城市内涝对自然环境和人类健康造成不利影响，并对资产和通信系统构成重大风险。在人口密度较高的城市，洪水破坏的程度在很大程度上取决于洪水泛滥范围和洪水深度。本研究比较了中国和日本两个高度发达的特大城市，即武汉市和熊本市，在 2020 年的洪水泛滥范围、造成的破坏和可能的洪水深度。利用 Google Earth Engine（GEE）中的 Sentinel-1 卫星数据驱动的变化检测算法，识别出潜在的洪水泛滥区域。结合暴露人口，绘制了受洪水影响的主要土地利用/土地覆盖类别，如城市地区和耕地。利用 ALOS PALSAR 数字高程模型（DEM）研究了淹没深度。研究结果表明，武汉市有 322 公里的地区被洪水淹没，其中受损耕地和城区分别为 230 公里和 140 公里。约有 817095 人在这场自然灾害中受到影响。熊本市的洪水淹没面积约为 505 公里，其中受损耕地为 350 公里，城区为 83 公里。
