为了探究近20 年来洞庭湖萎缩状况, 定量评价其水面面积变化情况, 选择Landsat TM 遥感影像作为数据 源, 采用单波段阈值分析法、多波段谱间关系法、水体指数法、植被指数法和目视解译法对洞庭湖水体进行了解译, 探讨了1993 年- 2010 年洞庭湖水体面积动态变化状况。结果表明, 若以1949 年洞庭湖面积( km2 ) 作为历史参考 水面, 则18 年间湖面积萎缩严重, 秋季平水期萎缩比例均超40%; 若以1978 年洞庭湖水面为参考, 则萎缩比例少 于40%。研究还表明, TM 图像的72422 波段组合对于洞庭湖水体的解译非常有效, 可以作为地区水文水资源研究 的重要手段。

In o rder to investigate the shrinking conditio ns of the Dongting Lake in r ecent 20 years and evaluate the chang e in w a2 ter sur face area quantitatively , the Landsat2TM remot e sensing images wer e used as t he dat a sour ce, and the single band thresh2 o ld alg or ithm, mult i2band spectrum, no rmalized difference wat er index, normalized difference v egetation index , and v isua l inter2 pretat ion wer e used to analy ze the chang e in water sur face ar ea of the Dongt ing Lake fr om 1993 to 2010. Based o n the analy sis of spectro sco pic cha racterization of Landsat2TM remot e sensing data o f the study area, the fractal dimension of the surface w ater area of the Do ng ting Lake w as calculated. The w ater sur face ar ea of the Dongting Lake is 1604. 29 km2 in Octo ber 1993, 848. 73 km2 in September 2001, 414. 32 km2 in November 2006, and 330. 92 km2 in December 2010. Take the water surface area in 1949 ( 4350 km2 ) as the histor ical r eference v alue, Do ng ting Lake shr ank severely in r ecent 30 years, and the shr inking pr opor tion of the Do ng ting Lake sur passed 40% during the no rmal riv er flow per iod. T ake the w ater surface area in 1978( 2691 km2 ) as the hist orical r efer ence va lue, and the shr inking pr opor tion of the Dongt ing Lake w as less than 40%. The results show ed that 72422 band v isual inter pr et ation can be effect ively applied to the interpretat ion o f the Landsat2TM r emote sensing images in the Dongting Lake.

中央高校基本科研业务费专项资金项目( 2014XS68) ; 国家杰出青年科学基金( 51225904)