青藏高原多年冻土区热喀斯特湖水文特征及环境效应  

Hydrological characteristics of thermokarst lake and its environmental effects on Qinghai-Tibet Plateau

作　　者：高泽永 牛富俊 王一博[2] 王玮[3] 林战举 罗京 吕明侠 GAO Zeyong;NIU Fujun;WANG Yibo;WANG Wei;LIN Zhanju;LUO Jing;LYU Mingxia(State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Science,Lanzhou 730000,China;Key Laboratory of Western China′s Environmental Systems of the Ministry of Education,Lanzhou University,Lanzhou 730000,China;Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of the Ministry of Education,Chang′an University,Xi′an 710054,China)

机构地区：[1]中国科学院西北生态环境资源研究院冻土工程国家重点实验室,甘肃兰州730000 [2]兰州大学西部环境教育部重点实验室,甘肃兰州730000 [3]长安大学旱区地下水文与生态效应教育部重点实验室,陕西西安710054

出　　处：《水科学进展》2022年第2期174-184,共11页Advances in Water Science

基　　金：国家自然科学基金资助项目(41901083);甘肃省自然科学基金资助项目(21JR7RA051)。

摘　　要：全面认识热喀斯特湖水文过程的季节变化特征是准确评估其生态环境效应的关键。以青藏高原典型热喀斯特湖为例,基于2018—2020年水文气象要素的野外观测及计算,分析热喀斯特湖的水文特征及产生的环境效应。研究结果表明:①春季降水补给热喀斯特湖,迅速升高湖塘水位,其中湖塘的储水量与湖塘水位之间存在较好的幂函数关系;②湖面年均蒸发量和湖冰年均升华量分别可达738 mm和198 mm,受温度升高的影响,未来有增多的可能;③热喀斯特湖水中离子质量浓度在暖季初期和后期较高,冷季湖冰形成过程中自净作用和地球化学过程的影响使各离子表现出不同的迁移机制。受局地因素的影响,热喀斯特湖的水文要素呈明显的季节变化特征,水文循环过程会引起多年冻土退化、湖岸坍塌后退、水环境恶化、温室气体释放、土壤盐渍化、植被退化等,未来研究需对整个高原地区热喀斯特湖的环境效应进行全面评估。A comprehensive understanding of the hydrological processes of thermokarst lakes on a seasonal scale is key to evaluating their environmental effects.In this study,a typical thermokarst lake was selected on the Qinghai-Tibet Plateau(QTP)and the meteorological and hydrological parameters were measured and calculated(2018—2020 to analyze the hydrological characteristics and environmental effects.The following results were obtained:①Rainfall in spring recharges thermokarst lake water quickly and elevates lake water level rapidly;a power function was exhibited between lake water storage and water levels.②The average annual lake evaporation and lake ice sublimation were 738 mm and 198 mm,respectively.Under the influence of rising air temperature,lake evaporation and ice sublimation may be increased in the future.③The ionic concentrations in lake water exhibited a high value in the initial and later periods of the warm season,and the self-purification of lake ice and geochemical processes resulted in different ion migration mechanisms.The hydrological elements exhibited obvious seasonal variation characteristics owing to the effect of local factors.Moreover,the hydrological processes involving thermokarst lake evolution can cause permafrost degradation,lakeshore collapse and receding,water environment deterioration,greenhouse gases release,soil salinization,and vegetation degradation.Thus,the environmental effects of thermokarst lakes should be evaluated on the entire QTP in future studies.

关 键 词：冻土退化 冻融过程 环境效应 热喀斯特湖 青藏高原 

分 类 号：TV642.14[水利工程—水利水电工程]