青藏高原多年冻土区不同高寒草地类型地表形变特征  

Ground surface deformation characteristics of different alpine-grassland types in the permafrost zones of Qinghai-Tibet Plateau

作　　者：王志伟[1,2,3] 岳广阳 吴晓东 WANG Zhiwei;YUE Guangyang;WU Xiaodong(Guizhou Institute of Prataculture,Guizhou Academy of Agricultural Sciences,Guiyang 550006,China;Cryosphere Research Station on Qinghai-Xizang Plateau,State Key Laboratory of Cryospheric Science,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730020,China;Department of Geological Sciences,University of Texas at San Antonio,San Antonio 78249,USA)

机构地区：[1]贵州省农业科学院草业研究所,贵阳550006 [2]中国科学院西北生态环境资源研究院冰冻圈科学国家重点实验室青藏高原冰冻圈观测研究站,兰州730020 [3]美国德克萨斯州大学圣安东尼奥分校地质学系,美国圣安东尼奥78249

出　　处：《生态学报》2021年第6期2398-2407,共10页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(41571075,41701077,41861016)。

摘　　要：作为气候变化"指示器"的青藏高原多年冻土,近几十年来受到越来越多学者关注。但是已有冻土区地表形变的研究,多单纯针对地表抬升和沉降量进行分析,鲜有针对不同高寒草地类型进行深入挖掘的。在位于青藏高原多年冻土区腹地的五道梁地区,利用ASAR数据和SBAS-InSAR方法反演了区域内2005年4月到2010年7月的地表形变状况。结果显示研究区地表形变速率基本位于±8 mm/a之间。其中,变形率为正、地表呈现抬升的区域占57.70%,地表形变为负、地表沉降的区域占42.30%。此外,高寒草地整体表现地表下沉的现象,而且高寒草原的地表沉降现象明显强于高寒草甸地区。计算获得3种生态遥感指数后,分析地表形变与生态遥感指数的相关性,发现针对不同草地类型,其地表形变的主导因子存在差异。高寒草甸的地表形变有可能更多的受限于温度变化,而高寒草原的地表形变则可能更多的由水分条件所影响。以上研究说明青藏高原多年冻土区植被类型条件越好,地表沉降量越小。因此今后的相关研究需要对植被类型条件差的区域增加更多的关注,因为这些地区易发生地表沉降,导致其生态系统稳定性较差。Global warming has received great attention from different research community, especially the warming changes of permafrost in Qinghai-Tibet Plateau(QTP) is one of the core study topics of global terrestrial ecosystems in recent decades. Because shifts of permafrost affect water circulation, biological diversity, geophysical process and carbon storage in this fragile plateau region. Permafrost, which has remained two or more years at or below the freezing point, has been considered as an indicator of climate changes. Existing studies lack detailed description of the response of permafrost change to different vegetation types, just focus on the analysis uplift and subsidence of ground surface. In this paper, ground surface deformation of permafrost in different type of alpine grasslands will be explored. The study area is located in Wudaoliang, which is one hinterland zone of QTP permafrost zone. The ground surface deformation of this region is inverted by advanced synthetic aperture radar(ASAR) data and the small baseline synthetic aperture radar interferometry(SBAS-InSAR) method. There were 24 ENVISAT ASAR images acquired from April 7 th, 2005 to July 15 th, 2010. They were employed to calculated the ground surface deformation, and the results showed that deformation rates of ground surface are primarily between ±8 mm/a. The area of positive deformation rate accounts for 57.70%. In this region, ground surface is uplifted. Conversely, area of negative surface deformation occupies 42.30%, where is subsidence region. The results were demonstrated that SBAS-InSAR technique can provide a useful tool to monitoring the surface deformation of different alpine vegetation types in permafrost regions. Furthermore, the ground surface of alpine grassland is subsidence mainly. And the surface subsidence is large in alpine grassland, compared with alpine meadow. In this study, there were 3 types of remote sensing based ecological indexes(RSEI), including normalized differential green index(NDGI), normalized differential wet i

关 键 词：活动层 气候变化 SBAS-InSAR ASAR 

分 类 号：S812[农业科学—草业科学]