近40年西藏高原北部4个内陆湖泊面积变化及气候要素分析

Analysis 4 Inland Lakes area variation and its climate factors in Tibetan Plateau in last 40 years

格仁错、孜桂错、吴如错、恰规错4个湖泊是西藏高原北部内陆湖泊群。文章通过近40年LandsatTM/ETM+的遥感影像数据及气象观测数据,对1976-2016年4个湖泊的面积变化进行分析。结果表明:1976-2016年4个湖泊面积总体上呈减少趋势,但是减少幅度较小。1976-2016年4个湖泊最大面积都出现在21世纪初,最小面积除吴如错在1995年以外,其余湖泊均出现在2015年,而吴如错2015年的面积仅比1995年的多0.5km2;1970-2016年间4个湖泊的气象要素显示气温升高、降水量增加、蒸发量减少,通过湖泊面积与气象要素之间的相关分析得出,4个湖泊与降水量的相关性最显著。与藏北其他内陆湖泊不同,文章研究的4个湖泊面积均呈略微缩小趋势,这可能与4个湖泊和色林错之间通过河流相互贯通,在色林错面积增大的背景下经西岸流进色林错的水量有一定的关系,有待进一步研究。

The variation in acreage of four inland lakes(Gering Tso,Zigui Tso,Wuru Tso and Qiagui Tso)in last 40 years(from 1976 to 2016)in the northern part of the Tibetan Plateau and its reasons were analyzed with Landsat TM/ETM+/OLI data.The overall area of the four lakes showed a decreasing trend generally in last 40 years(1976 to 2016)with a small magnitude change.The largest area of the four inland lakes appeared at the early twenty-first century and the smallest area appeared in year 2015 except Wuru Tso,the area of Wuru Tso in 2015 was 0.5 km2 larger than that in 1995.The temperature and precipitation in the study area have been increased during the 40(from year 1970 to 2016)years,but the evaporation has been decreased in the same period of time.The results of correlation analysis between the lake area and meteorological factors showed that the change in area of the four lakes was mainly affected by precipitation in compression with other inland lakes in northern Tibet.The area of four lakes studied in this paper showed a decreasing trend in general and this could be result from linking between the four lakes and Selin Tso through rivers.