基于Sentinel-1数据的典型地物特征分析与洪水区面积提取  

Typical Ground Object Feature Analysis and Flood Area Extraction Based on Sentinel-1 Data

作　　者：李颖[1,2] 陈怀亮[1,3] 叶昊天 周兆基 Li Ying;Chen Huailiang;Ye Haotian;Zhou Zhaoji(CMA·Henan Key Laboratory of Agrometeorological Support and Applied Technique,Zhengzhou 450003,China;Henan Institute of Meteorological Sciences,Zhengzhou 450003,China;Harbin Meteorological Bureau,Harbin 150028,China;Henan Meteorological Bureau,Zhengzhou 450003,China)

机构地区：[1]中国气象局·河南省农业气象保障与应用技术重点开放实验室,郑州450003 [2]河南省气象科学研究所,郑州450003 [3]哈尔滨市气象局,哈尔滨150028 [4]河南省气象局,郑州450003

出　　处：《气象与环境科学》2022年第6期1-8,共8页Meteorological and Environmental Sciences

基　　金：国家自然科学基金项目(41805090);气候变化专项课题(CCSF201934)。

摘　　要：气候变化导致近年来洪涝灾害频繁发生,利用SAR影像提取洪水区面积的方法因不受云雨雾天气影响,已得到广泛应用。由于国内相关研究往往仅进行新增开放水体的提取,没有开展新增湿地的识别,且较少考虑入射角对不同典型地物的后向散射系数影响等问题,因而结果存在一定的局限性。以2018年美国南北卡罗来纳州部分洪水泛滥的区域为研究区,基于Sentinel-1卫星数据,提出一种更为全面的洪水区面积提取方法:在分析不同地物类型的后向散射系数随局地入射角的变化情况和不同地物类型的纹理特征的基础上,利用ISODATA算法提取开放水体,进行了洪水发生后新增湿地与灌木、森林的极化分解分析;最后利用阈值法提取新增湿地面积。结果表明综合新增开放水体与新增湿地,可以得到更为完整的洪水区面积。Climate change has led to frequent floods in recent years. The method of extracting flood areas from SAR images has been widely used because it is not affected by cloud, rain and fog. However, the domestic related researches often only extract newly opened water bodies without identifying newly added wetlands, and less consider the influence of incident angle on the backscattering coefficients of different typical ground objects, so the research results have some limitations. Taking part of flooded watersheds in North and South Carolina of the United States in 2018 as the study areas, this paper proposes a more comprehensive method for extracting flood area on the basis of the Sentinel-1 data. The variations of backscattering coefficient with local incidence angle and texture characteristics of different ground object types are analyzed. Based on the extraction of open water area by ISODATA algorithm, the polarization decomposition analysis of newly added wetlands, shrubs and forests after flood is carried out. The newly added wetland area is extracted by the threshold method. Finally, a more complete flood area is obtained by integrating the newly added open water bodies and newly added wetlands.

关 键 词：SAR影像 ISODATA算法 阈值法 极化分解 

分 类 号：P332[天文地球—水文科学] TN957.52[水利工程—水文学及水资源]