基于Sentinel-1与Landsat 8的巢湖地区洪水淹没灾害分析

为及时准确得到阴雨天气下的洪水淹没区域及受灾情况，以巢湖流域作为研究区域，选择灾前、灾后的Sentinel-1影像作为数据源，基于SDWI指数及直方图双峰法提取水体信息，结合Landsat 8数据对山体阴影进行去除，快速提取洪水淹没范围，分析洪涝灾害前后时空变化特征，并结合Landsat 8数据获取的土地利用类型分类图，对受灾地区进行灾情评估。结果表明：2020年6—9月巢湖流域重灾区域集中于巢湖西部、东部、北部，耕地、居民地受灾程度严重；利用多时相Sentinel-1影像快速提取洪涝受灾情况，可为国家减灾备灾、应急救灾、恢复重建工作提供有力的数据支撑。

Flood inundation disaster analysis in Chaohu Area Based on sentinel-1 and landsat8

In order to timely and accurately obtain the flood inundation area and disaster situation under wet weather, this paper takes Chaohu Basin as the research area. The Sentinel-1 images before and after the disaster are selected as the data source. Surface water information is extracted based on SDWI index and histogram bimodal method, and the mountain shadow is removed in combination with Landsat 8 data, so as to quickly extract the flood inundation area and analyze the spatial-temporal variation features before and after the flood disaster. Based on the map of land use classification from Landsat 8 data, the disaster in the affected areas is evaluated. The results show that from June to September 2020, the heavily affected areas in Chaohu Basin are concentrated in the west, east and north of Chaohu Lake, where cultivated land and residential areas are seriously affected. Using multi-temporal sentinel-1 images, the flood disaster situation can be quickly extracted, which can provide strong data support for national disaster reduction and preparedness, emergency response, recovery and reconstruction.