Characteristics of lake-glacier change in source region of the Yangtze River and its response to climate change
Lakes are sensitive indicators of climate change,and studying their dynamic changes was of great sig-nificance to reveal global climate change and water resources utilization and management.Based on Landsat-5/7/8 satellites and high-resolution remote sensing images,the temporal and spatial characteristics of lake area change during 1989-2021 in Dorsodong Co-Mitijiangzhanmu Co in source region of the Yangtze River were an-alyzed,and the response of glacial lake and glacier to climate change was discussed.The results showed that during 1989-2021,the average area of Dorsodong Co-Mitijiangzhanmu Co was 1 011.37 km2,which expand-ed from 872.07 km2 in 1989 to 1 119.5 km2 in 2021,with an average expansion rate of 8.62 km2⋅a-1.In terms of interdecadal variation,the lake area expanded most obviously in the early 21th century,especially in the north-ern,northwestern and southern parts of the lake.Growth was slowest in the 1990s.From 1990 to 2020,the area of Geladandong Glacier shrank from 797.85 km2 in 1990 to 766.19 km2 in 2020,a decrease of 31.66 km2,with a reduction rate of 1.106 km2⋅a-1.Between 2015 and 2022,the glacier area decreased by 19.55 km2.From 2005 to 2010,the glacier area decreased by 1.50 km2.Glacier retreat accelerated from 0.51 km2 in 1990 to 2.20 km2 in 2010.Before 2004,glacial meltwater caused by rising temperature was the main factor of Dorsodong Co-Miti-jiangzhanmu Co lake area change,with an average contribution of 66.8%.After 2004,precipitation played a leading role in the change of Dorsodong Co-Mitijiangzhanmu Co lake area.The average contribution rate of pre-cipitation to lake area change was 57.8%.Through the analysis of net evaporation,it can be found that the net evaporation of Bangor,Shenza and Amdo all showed a downward trend year by year,especially the net evapora-tion of Shenza Station showed a significant downward trend,and the decline rate was 7.8 mm⋅a-1.Therefore,it can be found that the net evaporation of Dorsodong Co-Mitijiangzhanmu Co area decreased,and the lake area al-so increased with the decrease of evaporation.From the perspective of mass balance and lake water volume change,the correlation between mass balance and lake water volume in Geladandong Glacier was 0.69,indicat-ing that glacier mass loss contributes to the increase of lake water volume.The mass balance of Geladandong Glacier lost the most in 2016,the lake area increased by 16.4%and the lake water volume increased by 3.16 Gt compared with 2000.In 2005,the glacier was in a state of accumulation,the lake area was only 0.67%com-pared with 2000,and the lake water volume increased by 0.9 Gt compared with 2000.From 2000 to 2004,the lake area expanded by 5.1%,and the glacial meltwater was about 4.56 Gt.From 2005 to 2016,the lake area ex-panded by 6.9%,and the glacial melt water was about 1.94 Gt.It can be seen that the contribution rate of gla-cier loss to lake from 2000 to 2004 was about 80%.After 2004,the contribution of glacier loss to lake water vol-ume will reach 40%.
Dorsodong Co-Mitijiangzhanmu Coclimate changesource region of the Yangtze Riverlake dynamicsglacier dynamics
NETL
NSTL
万方数据
