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为准确了解青藏高原多年冻土退化过程及其环境效应,中国科学院寒区旱区环境与工程研究所和德国海德堡大学环境物理研究所共同组成科研小组,先后对我国三江源区、西昆仑甜水海地区进行了多年冻土退化过程的前期勘察研究工作.首次在人烟稀少的玉树-不冻泉沿线等地建立了3个长期综合观测研究站.在技术手段上,除应用常规的坑探、水土取样、水分现场观测、地面调查外,主要应用了最新的双天线、多回路探地雷达勘测技术,对不同地貌条件下的活动层结构特征、上限附近冻土结构、冷生组构等诸多方面进行了快速勘察,同时还进行了水分场分布规律、盐份迁移过程的初步研究.研究结果表明:地表景观特征对热质迁移规律、地温场具有重要影响;青藏高原新疆甜水海地区的低温(<-4℃)冻土与高原东部和腹地的高温(>-1℃)冻土在地质背景和地下冰发育情况等方面有所区别;甜水海地区生态环境在过去30多年的时间里已发生重大改变:地表植被发生大面积退化,地表普遍发生不同程度盐渍化;在该地区发现大量小型冻胀丘、石环等冰缘现象的存在.探地雷达勘察结果显示,地表地貌单元、植被分布、地表水分条件的变化均对多年冻土上限变化和地下冰的赋存产生重要影响.
In order to understand accurately the process of permafrost degeneration and its environmental effects in the Qinghai-Tibet Plateau, the Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences and the Institute of Environmental Physics, Heidelberg University jointly set up a scientific research group. The region conducted preliminary investigation and research work on the permafrost degradation process.For the first time in the sparsely populated Yushu - along the frost spring and other places to establish three long-term comprehensive observation station.In technical means, in addition to the use of conventional pit exploration, soil and water sampling , Water field observation and surface survey, the latest double antenna and multi-circuit GPR survey techniques are applied. The characteristics of the active layer structure under different geomorphological conditions, the structure of permafrost near the upper limit, and the structure of cold birth are mainly carried out The results showed that: the landscape characteristics of the landscape have an important impact on the laws of heat and mass migration and the geotemperature field; the low temperature (<120 ℃) in the sweet water region of Xinjiang in the Qinghai-Tibet Plateau, -4 ℃) Permafrost and the high temperature (> -1 ℃) permafrost in the eastern and hinterland of the plateau in the geological background and the development of underground ice Etc. In the past 30 years, the ecological environment in Tianshuihai has undergone significant changes: large-scale degeneration of surface vegetation and varying degrees of salinization occur on the ground surface; a large number of small-scale frozen domes and rocks are found in the area Etc. The results of GPR survey show that the change of topography units, vegetation distribution and surface water conditions have an important impact on the change of the upper limit of permafrost and the occurrence of underground ice.