近40a藏西北鲁玛江冬错湖面变化的多源卫星遥感监测

Remote Sensing Monitoring of Lake Surface Changes in Lomachangdongtso Lake in Northwest Tibet in Recent 40 Years

选取1992~2018年Landsat(TM\ETM\OL_TRIS)和高分1号(GF1-WFV2)卫星遥感数据和1970~2018年气象观测资料,基于1975年地形图数据,分析鲁玛江冬错湖面面积变化规律,研究该湖对气候变化的响应情况。结果表明:(1)1975~2018年鲁玛江冬错湖面面积总体呈增长趋势,扩张了55.82 km^(2),扩张率为13.97%;尤其是2001~2017年湖泊面积增长了49.18 km^(2),增幅为12.26%;从空间变化特征看,鲁玛江冬错水域面积向四周扩展,其中湖泊西南部和东部变化较明显。(2)1970~2018年鲁玛江冬错流域地表年平均气温呈显著上升趋势,气候倾向率为0.55℃/10 a;年降水量总体呈增加趋势,气候倾向率为9.84 mm/10 a;年蒸发量总体呈弱的减少趋势,气候倾向率为−2.22 mm/10 a。近40 a鲁玛江冬错湖泊面积与年降水量、年平均气温之间均呈正相关,该流域气温升高和降水增加可能是导致鲁玛江冬错湖面面积增长的重要因素。

Based on Landsat(TM\ETM\OLI-TIRS)and GFI_WFV2 satellite remote sensing data from 1992 to 2018 and meterological observation data from 1970 to 2018,the change law of lake area of Lomachangdongtso lake was analyzed.The results indicate that:(1)The lake area showed an overall increasing trend from 1975 to 2018,increased about 55.82km^(2) and growth rate is 13.97%,especially,the lake water area increased about 49.18km^(2) from^(2)001 to 2017,and growth rate is 12.26%.The spatial dynamic distribution of the water area of Lomachangdongtso lake extended to all sides,and the changes were more obvious in the southwest and east of the lake.(2)Meteorological data from 1970 to 2018 displayed that the annual surface temperature in the basin showed a significant increase trend,with an average increased of 0.55℃every 10 years.The annual precipitation was increased with an average of 9.84mm per 10 years.Evaporation presented a weak tendency of decreasing with an average of 2.22mm per 10 years.There was a positive correlation between lake area and annual average precipitation in Lomachangdongtso lake,and the annual mean temperature was positively correlated.It reflected that the temperature and precipitation were the certain effects on the change of lake surface.