基于SAR卫星遥感技术的农田洪涝灾害信息提取技术

The information extraction technology of farmland flood disaster based on SAR satellite remote sensing technology

为提高农田洪涝灾害信息提取能力,探索了SAR卫星遥感影像水体及农田边界信息的自动提取方法。以江西丰城某次强降雨过程为例,采用阈值分割法、雷达及光学影像融合法,利用Sentinel-1卫星影像对灾前水体信息进行提取,巢湖一号卫星影像对灾中的水体信息进行提取,将二者提取信息进行叠加,得到本次强降水新增水体范围;利用Sentinel-2卫星影像,叠加天地图影像提取出研究区域的农田边界范围,将该边界与新增水体范围叠加,得到受本次强降雨影响农田洪涝灾害区域的范围。经评价,该方法可有效提高地物散射特征的分类精度,提取的11处受淹农田验证地块完整率均在80%以上。SAR遥感影像不受云雨天气影响,能够在洪涝灾害应急监测中提供有力的数据支撑,该分析方法有利于相关部门全面掌握农田灾情数据,迅速做出应急响应,提高洪灾的应急救助管理能力。

In order to improve the extraction ability of farmland flood disaster information,the automatic extraction method of water body and farmland boundary information of SAR satellite remote sensing image was explored.Taking a heavy rainfall process in Fengcheng,Jiangxi Province as an example,the threshold segmentation method,radar and optical image fusion method was adopted,Sentinel 1 satellite image was used to extract water information before the disaster,and chaohu 1 satellite image was used to extract water information in the disaster.The two results were superimposed and the new water body range of the heavy precipitation was ob⁃tained.The satellite images of Sentinel 2 were used to superimpose the sky map images to extract the farmland boundary range of the study area,and this boundary was superimposed with the new water body range to obtain the scope of the farmland flood disaster area affected by the heavy rainfall.Through evaluation,this method could effectively improve the classification accuracy of ground scatter⁃ing features,and the integrity rate of the extracted 11 flooded farmland verification plots was above 80%.SAR remote sensing image was not affected by cloud and rain weather,and could provide strong data support in the emergency monitoring of the flood disaster.This analysis method was conducive to the relevant departments to fully grasp the farmland disaster data,make emergency response quickly,and improve the emergency rescue and management ability of flood.