通过整理解译 1969 年航片、1986 年、2000 年、2007 年以及 2013 年 TM（Thematic Mapper）影像数据，对长江黄河源区的高寒湿地分布的时空变化特征进行分析，并结合气象观测数据和人类活动状况，运用主成分分析和灰色关联度法定量分析造成高寒湿地退化的气候因素和人为因素的贡献，并揭示了高寒湿地退化与各环境因子之间的关联性。结果表明：1969 年—2013 年间，江河源区的高寒湿地面积减少了 19.16 %，各湿地类型的斑块分离度不断增大；空间上，高寒湿地的退化区主要分布在长江源区的东北部以及黄河源区的北部地区，与该区域冻土的退化有显著的一致性；1969 年以来，江河源区的气候呈气温显著上升、相对湿度降低以及降水量微弱增加的暖干化趋势，湿地的退化与气候变化在时间上有明显的同步性，其中气温升高是形成湿地退化格局的主要原因，降水量和相对湿度的变化会对湿地的变化产生重要影响，尤其是对河流和湖泊的影响更为显著; 此外，载畜量的变化是影响湿地变化最重要的人为因素。 更多还原

Alpine grassland is the main vegetation type in the source regions of the Yangtze and Yellow Rivers，and accounts for about 70% of the total area in this region． As a result，maintenance of ecosystem balance，water cycling and soil-atmosphere exchanges in these regions critically depends on the status of the local alpine grasslands． With current global changes such as climate change，and increased human population in the region，alpine grassland in this region has been subject to increasing grazing pressure with significant changes resulting． These environment and regional economic
changes have attracted widespread attention． In this research，alpine grassland degradation in the source regions of Yangtze and Yellow Rivers was quantified by analysis of images obtained by aerial photography in 1969 and TM remote sensing data captured in 1989，2000，2007 and 2013． In addition，with the inclusion of climatic observation data and data on human factors，the causes of the degradation were analyzed by principal component analysis and the gray correlation method． The results show that the alpine grassland degradation is characterized by reducing coverage，and increasing fragmentation and desertification． The total area of mid-cover alpine grassland and high-cover alpine grassland has decreased by 16． 33% from 1969 to 2013． With a trend to increase in periodic drought，the total area of alpine meadow
has decreased by 3． 75% during the same time． Fragmentation and separation of alpine grassland units in the landscape has been occurring and also shrinkage and disappearance of patches． The rate of degradation increased very rapidly after the 1980s，and reached its maximum in 2000，but has been consistently decreasing since 2000． Climatic drought caused by a warming trend has been the main driver for alpine grassland degradation in the source regions of Yangtze and Yellow Rivers，and overstocking and unreasonable human activity were important contributing factors，intensifying the degradation．