基于多源遥感数据的乌伦古湖面积动态变化分析

Analysis of water surface area variation of Ulungur Lake based on multi-source remote sensing data

为精准研究乌伦古湖面积变化趋势,利用研究区1989~2017年高分辨率Landsat遥感影像,在分析不同水体提取方法优劣的基础上,利用改进的归一化差异水体指数法提取乌伦古湖水体面积,识别乌伦古湖面积的时空变化特征。结果表明:乌伦古湖水体面积2002年最大(1 045.33 km2),2006年最小(1 010.03 km2)。总体而言,近30 a乌伦古湖水域面积变化呈扩张-缩小-扩张-相对稳定的动态变化特征。2002~2006年为湖泊萎缩最显著的时期,与该时期乌伦古河出现季节性断流导致入湖水量急剧减少的现象一致。

In order to accurately study the water surface area variation trend of Ulungur Lake,based on the analysis of the advantages and disadvantages of different water body extraction methods,the improved normalized difference water index method and high-resolution Landsat remote sensing images of the research area from 1989 to 2017 were used to extract the water surface area of Ulungur Lake and its spatial-temporal variation characteristics were identi⁃fied.The results showed that the water surface area of Ulungur Lake was largest(1045.33km2)in 2002 and smallest(1010.03km2)in 2006.Generally speaking,the variation of the water surface area of Ulungur Lake in the past 30 years showed the dynamic variation of expansion-reduction-expansion and stable relatively.The lake shrunk most significantly from 2002 to 2006,which was consistent with the sharp decrease of lake inflow caused by seasonal in⁃terruption of the Ulungur River.