Large-scale characteristics of thermokarst lakes across the source area of the Yellow River on the Qinghai-Tibetan Plateau  

作　　者：LIU Wen-hui ZHOU Guang-hao LIU Hai-rui LI Qing-peng XIE Chang-wei LI Qing ZHAO Jian-yun ZHANG Qi 

机构地区：[1]State Key Laboratory of Plateau Ecology and Agriculture,Qinghai University,Xining 810016,China [2]Department of Geological Engineering,Qinghai University,Xining 810016,China [3]College of Eco-Environmental Engineering,Qinghai University,Xining 810016,China [4]Cryosphere Research Station on the Qinghai-Tibet Plateau,State Key Laboratory of Cryosphere Sciences,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 73oooo,China

出　　处：《Journal of Mountain Science》2023年第6期1589-1604,共16页山地科学学报（英文）

基　　金：supported by the Natural Science Foundation of Qinghai Province,China(No.2021-ZJ940Q);the Open Project of State Key Laboratory of Plateau Ecology and Agriculture,Qinghai University(No.2022-ZZ-02)。

摘　　要：As significant evidence of permafrost degradation,thermokarst lakes play an important role in the permafrost regions by regulating hydrology,ecology,and biogeochemistry.In the Sources Area of the Yellow River(SAYR),permafrost degradation has accelerated since the 1980s,and numerous thermokarst lakes have been discovered.In this paper,we use Sentinel-2 images to extract thermokarst lake boundaries and perform a regional-scale study on their geometry across the permafrost region in the SAYR.We also explored the spatiotemporal variations and potential drivers from the perspectives of the permafrost,climate,terrain and vegetation conditions.The results showed that there were 47,518 thermokarst lakes in 2021 with a total area of 190.22×106 m^(2),with an average size of 4,003.3 m^(2).The 44,928 ponds(≤10,000 m^(2))predominated the whole lake number(94.1%)but contributed to a small portion of the total lake area(28.8%).With 2,590 features(5.9%),small-sized(10,000 to 100,000 m^(2))and large-sized lakes(>100,000 m^(2))constituted up to 71.2%of the total lake area.Thermokarst lakes developed more significantly in warm permafrost regions than in cold permafrost areas;74.1%of lakes with a total area of 119.6×106 m^(2)(62.9%),were distributed in warm permafrost regions.Most thermokarst lakes were likely to develop within the elevation range of 4,500~4,800 m,on flat terrain(slope<10°),on SE and S aspects and in alpine meadow areas.The thermokarst lakes in the study region experienced significant shrinkage between 1990 and 2021,characterized by obvious lake drainage;the lake numbers decreased by 5418(56.1%),with a decreasing area of 58.63×106 m^(2)(49.0%).This shrinkage of the thermokarst lake area was attributable mainly to the intensified degradation of rich-ice permafrost thawing arising from continued climate warming,despite the wetting climatic trend.

关 键 词：Thermokarst lake Spatial characteristic Influencing factor Source area of the Yellow River 

分 类 号：P343.3[天文地球—水文科学]