基于Landsat卫星遥感资料的河流水温反演研究  

Derivation of river surface temperature from Landsat thermal infrared data

作　　者：石希 孙健[1] 史立地 SHI Xi;SUN Jian;SHI Lidi(State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084)

机构地区：[1]清华大学水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《水力发电学报》2021年第2期121-130,共10页Journal of Hydroelectric Engineering

基　　金：国家重点研发计划(2016YFA0600901,2016YFE0133700);国家自然科学基金面上项目(51779121)。

摘　　要：水温是影响河流环境与生态过程的重要因素。应用卫星遥感资料反演海洋和湖泊等大尺度水体温度的方法流程已较为成熟,但对于河流或河道型水库,受河道尺度、岸线边界及河道内船舶等随机因素影响,水温反演数据质量较差,目前还没有较完整的数据处理流程。本文基于Landsat系列卫星数据,应用大气辐射传输模型反演了三峡水库库首庙河站及库尾寸滩站两个特征站位的水体表面温度,并使用增强水体获取方法进行水体-陆地边缘效应的剔除,采用不同验证窗口选取方法确定的反演温度与实测水温进行比对验证。研究结果表明,剔除边缘异常像素可显著提高水温反演精度,误差可降低0.2℃以上;相较于单栅格法,利用方形选框法可使误差降低约0.1℃;本文所提出的水温反演方法在两个特征研究区域内具有相同的精度,并且Landsat-5的反演精度较Landsat-7更高,其均方根误差处于0.87~0.91℃。本文反演方法和数据处理过程可为今后使用Landsat系列卫星遥感影像获取河道内水温数据提供参考数据处理流程。River surface temperature(RST)is a crucial factor of river environment and ecology.Currently,methods to retrieve the surface temperature of large waterbodies in oceans and shallow lakes are relatively mature,but RST estimation lacks widely accepted approaches since its accuracy depends on the boundary effect of river banks and the stochastic factors of river channels.This study converts Landsat thermal infrared images to RST data using the radiation transfer model for two study areas,Cuntan and Miaohe in the Three Gorges reservoir region,and eliminates the boundary effect of the data through an enhancing water body retrieval method.We adopt three data windows of different types for RST data extraction and compare them with in-situ measurements.Results show that the removal of the boundary effect reduces the errors in RST by 0.2℃;and that compared with the single raster selection,the square data window selection method reduces the errors by 0.1℃.The RMSEs for the two study areas are comparable,and Landsat-5 that is more accurate than Landsat-7 has errors in the range of 0.87-0.91℃.This study helps RST analysis in river engineering and promotes application of Landsat thermal infrared images.

关 键 词：水温 河流 卫星遥感 边缘效应 LANDSAT 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]