Thermal Regime at Bottom of Thermokarst Lakes along Qinghai-Tibet Engineering Corridor
Lin Zhanju
Niu Fujun
Luo Jing
Liu Minghao
Yin Guo??an
Abstract：Thermokarst lakes have greatly influenced landscapes in cold regions,and the thermal erosion of their lakeshores may induce ground instability that affects infrastructure.Our study area includes three sub-regions where thermokarst lakes have ob-viously extended:the Chumaerhe high plateau,Wudaoliang basin,and Beiluhe basin.Based on continual monitoring of four lakes,and sporadic observation of lake-bottom temperatures of many lakes using HOBO Sensors in 2009—2010,the thermal regime of lake bottoms and the relation between lake-bottom temperature and water depth are examined.The results show that in January,when ice cover was present,the lake-bottom temperatures at 90% of the lakes in Chumarhe high plateau were be-low 0 ℃,which is likely because of shallow depths and high salinity of lakes in the region.However,the lake-bottom tempera-ture of most lakes in Wudaoliang and Beiluhe basins were above 0 ℃,except in some lakes shallower than the maximum ice thickness.In general,lake-bottom temperature in the three sub-regions increased with water depth during this period.When lakes were free of ice between June and October,the lake-bottom temperatures in the three sub-regions were all warm and the highest temperature was near 18 ℃.The seasonal increase in lake-bottom temperature in summer is more rapid in shallower lakes,and the temperatures were inversely related to water depth.The annual variation in lake-bottom temperature approxi-mates a sinusoidal curve,with the coldest temperature occurring in January to February and the warmest in July to August.
Keywords：thermokarst lakelake bottomthermal regimefrozen soilQinghai-Tibet engineering corridor
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 179-188 )