近40年西藏色林错流域湖泊面积变化及影响因素分析

Lake Area Variation of Selin Tso in 1975~2016 and Its Influential Factors

  • 摘要: 本文根据1975年地形图、1976~2016年Landsat (MSS\TM\ETM\OLI-TIRS)卫星遥感数据以及流域周围的气象资料分析湖面面积和流域周围冰川变化,并探讨了湖泊面积变化的可能影响气象原因。结果表明:1975~2016年间色林错、错鄂和班戈错湖面面积变化趋势有所不同。这一段时间内色林错湖面面积一直处于增长态势,面积增长为757.35km2,增长幅度为46.7%,增长速率为475.2km2/10a;而错鄂湖面面积在这一段时间内有增有减,但面积增量较小,总体保持稳定,面积增长为3.07km2,增长幅度为1.17%;班戈错湖面在这一段时间内面积略有波动,呈增长趋势,增长为49.75km2,增长速率为19.71km2/10a。从空间动态分布来看,色林错扩大较明显的区域为该湖的北部,班戈错扩大明显区域在东北部。色林错流域,近50a降水量年际变化波动较大,总体上呈增加趋势,平均每10a增加13.72mm。地表年平均气温呈显著上升趋势,平均每10年升高0.37℃。20世纪70年代至90年代以气温偏低为主,进入21世纪后,气温快速升温。1986~2016年间色林错流域冰川面积呈现出退缩、减少状态,总共减少了50.16km2,冰川面积变化率为7.57%。综合分析表明,色林错流域湖泊面积变化与气温和降水都有关,同时反映出该区域气温升高使得冰川融水量增加对湖泊补给有一定的作用。

     

    Abstract: In current paper analyzed change of lake surface areas and drainage glacier according to 1975 topographic map, Landsat(MSS\TM\ETM\OLI-TIRS)satellite remote sensing data during 1976~2016, and meteorological data for drainage area. It also discussed the possible influence of the change of lake area. The results show that the change in the surface area of the lakes vary for Selintso Lake, Tsoer Lake, and Bangatso Lake during 1975~2016. And the change in the surface area of the Selintso Lake is increasing constantly and increased area is about 757.35km2, growth rate is 46.7%, rate of rise is about 475.2km2/10a; The surface area of Tsoer Lake fluctuated greatly during this period with increasing and decreasing, but the area increment was small. The Tsoer lake surface area growth for 3.07km2 and growth rate is 1.17%; Bangatso Lake surface area fluctuated slightly and increase for 49.75km2, the rate of rise is about 19.71km2/10a. From the dynamic change of space, we can see that the larger area of the Selintso Lake was obviously expanded to its north part. Bangatso Lake’s expansion eara is in the northeast part. The annual variation of precipitation in the near 50a has fluctuated greatly at Selintso lake basin. Overall, the trend is increasing, and average increased 13.72mm per 10a. The average annual surface temperature shows a significant upward trend, the increased average temperature is about 0.37℃ per a decade. The temperature were manly low in the 1970s to 1990s, but after into 21st century temperature increased rapidly. During 1986~2016 the glacier area of Selin tso basin shows withdrawal and decrease, total decreased 50.16km2 and the area change rate is 7.57%.Comprehensive analysis shows that the change of Selintso lake basin is related to temperature and precipitation. Meanwhile, it reflects the increase of temperature in the region, which has a certain effect on lake replenishment.

     

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