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

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 55.82km² and growth rate is 13.97%, especially, the lake water area increased about 49.18km² from 2001 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.