基于GF-6的可可西里典型湖泊水体面积提取方法研究

Extraction method and accuracy evaluation of typical lake water body in Hoh Xil region based on GF-6 WFV data

湖泊是气候变化的敏感指示器,快速准确地获取湖泊水体信息对区域气候变化研究、区域生态环境保护和治理具有重要意义。本文基于高分六号(GF-6)WFV数据,以可可西里地区4个湖泊为研究对象,分别采用单波段法、波段差值法、归一化差异水体指数(NDWI)法提取了水体面积,并以目视解译所得结果作为参考标准,对不同方法的提取结果进行了精度评价。结果表明,单波段法易受浅水区水体影响,但受积雪的影响较小,而波段差值法和NDWI法受积雪影响较大;NDWI法虽能有效提取浅水区水体,但仍受一定程度湖底沉积物的影响;波段差值法与单波段法和NDWI法相比,能有效区分浅水区水体和背景地物。

Lakes are sensitive indicators of climate change.It is of great significance to obtain lake water information quickly and accurately for the study of regional climate change and the protection and governance of regional ecological environment.According to the characteristics of GF-6 WFV satellite image data,four lakes at different locations in Hoh Xil area are selected as the research objects,and uses single-band method,band difference method and normalized difference water index(NDWI)water body information extraction in four lakes.The data obtained by visual interpretation are used as real ground data to evaluate the accuracy of different water body extraction methods.The results show that the results of single band method is easily affected by shallow water body,but less affected by snow,while band difference method and NDWI method are greatly affected by snow.Although NDWI can effectively extract shallow water body,it is still affected by lake bottom sediments to a certain extent.Compared with single band method and NDWI method,band difference method can effectively distinguish shallow water bodies and background features.