Bathymetric survey and thermal stratification of Lake Cherigele in the Badain Jaran Desert
LI Kezu;CAO Le;MENG Lingqun;LIU Xuequan;YAN Dongming;Institute of Hydrogeology and Engineering Geology,Gansu Bureau of Geology and Mineral Exploration and Development;Gansu Key Laboratory of Groundwater Engineering and Geothermal resources;Institute of Hydrogeology and Environmental Geology;
Most lakes at Badain Jaran Desert are now still lack of basal information,especially the survey of water temperature stratification and the discussion about its causes. In this study,field investigation including bathymetric survey and water quality measurements were conducted at 5 sections and 66 stations of lake Cherigele which is one of the largest lakes in the Badain Jaran Desert,in June 1 st and 2 nd,2016. The results showed that: 1) Isobathic map shows that lake Cherigele looks like a shallow dish and the maximum water depth is 8.2 m. This lake is divided into north and south lake basins because there is a uplift from east to west lay on the lakebed. There are some slopes with 1 ~ 2 m deep down near the shore at the lakebed,which is considered to be made from tufa. 2) According to the vertical variations of water temperature in June,water temperature of lake Cherigele could be divided into three layers with distinctly various features. The first layer as mixolimnion is from surface to 3 m depth in which water temperature and conductivity are relatively uniform. The second layer ranges about 3 ~ 4 m is a relatively high temperature area. And the bottommost layer is characterized with the linear decrease with the 3. 5℃/m gradient value. The conductivity value constantly increases with the 8. 264( m S/cm)/m gradient value. According to the temperature stratification comparison between in June 1 st and Aug. 9 th,we can find the water temperature of Cherigele rises in 5 ~ 6℃,while the thickness of mixolimnion increasing to6 m. In brief,we conclude that solar radiation and wind are the principal reason resulting in water temperature-layering and changes of the thermocline,and the freshwater inflow and lake basin structure take the second place. More data and information about water temperature,conductivity and water level throughout the year are needed to ensure which type of Cherigele is.
【Fund】： 国家青年科学基金项目(41702285);; 中国地质调查项目(121201106000150093);; 基本科研业务费(SK201505)联合资助
【CateGory Index】： P333
【CateGory Index】： P333