1971 - 2017年羌塘国家级自然保护区陆地生态环境变化

利用羌塘国家级自然保护区边缘5个气象站1971 - 2017年逐月平均气温、 平均最高气温、 平均最低气温、 降水量和逐年最大冻土深度等气象资料， 以及卫星遥感资料， 采用线性回归、 相关系数等方法， 分析了自然保护区气候（气温、 降水等）、 水体（湖泊、 冰川）和植被等生态环境因子的变化。结果表明： 近47年自然保护区年平均气温以0.46 ℃·（10a）^-1的速率显著升高， 明显高于同期全球和亚洲地表温度的升温率。四季平均气温升温率为0.37 ~ 0.55 ℃·（10a）^-1， 升幅在冬季最大、 夏季最小。年降水量呈明显的增加趋势， 增幅为11.0 mm·（10a）^-1， 主要表现在春、 夏两季。近43年（1975 - 2017年）色林错面积呈显著增加趋势， 平均增长率为38.48 km²·a^-1。1973 - 2017年， 普若岗日冰川面积整体上趋于减少， 平均每年减少2.11 km²； 自然保护区年最大冻土深度变化率为-35.7 cm·（10a）^-1。1999 - 2013年保护区NDVI增幅达25.3%， 平均每10年增加0.0184， 植被覆盖度明显增加。总之， 近47年自然保护区表现为气候暖湿化、 冰川退缩、 湖泊扩涨、 冻土退化、 植被覆盖增加的变化特征， 而冰川变化引发的水资源时空分布和水循环过程的变化， 无疑将给高原社会经济发展带来深刻影响。

Climatic and environmental features in Chang Tang National Nature Reserve during 1971 - 2017

Based on monthly mean air temperature， maximum temperature， minimum temperature， precipitation and annual maximum frozen soil depth datafrom five meteorological stations in Chang Tang Nature Reserve （CTNR） from 1971 to 2017， in combination with the satellite remote sensing data during 1973 - 2017， the changes in major ecological environment variables such as climate（e.g.， temperature and precipitation）， water（lakes， glaciers） and grassland vegetation were analyzed using the linear trend analysis and correlation analysis methods. The results shows that： （1） In the past 47 years （1971 - 2017）， the annual mean temperature had been significantly increasing with a rate of 0.46 ℃·（10a）^-1 in CTNR， a much higher rate than that in the global and Asia. The seasonal mean temperature inceased in CTNR at a rate of 0.37 - 0.55 ℃·（10a）^-1 with the maximunm rate occurring in winter， and the minimun rate in summer. Besides， the annual precipitation amount exhibited a significantin creasing trend with a rate of 11.0 mm·（10a）^-1， especially in spring and summer. （2） During the 1975 - 2017， the area of Selinco showed a significant expansion with a rate of 38.48 km²·a^-1. The coverage area of Puruogangri Glacier presented a shrinking tendency with a total retreated area of 2.11 km² from 1973 to 2017， and the maximum annual depth of permafrost in nature reserves was 35.7 cm per 10 years on average. （3） The NDVI in the reserve increased by 25.3% from 1999 to 2013， with an average increasing rate of 0.0184 per decade， indicating the vegetation coverage increased significantly. （4） Overall， this study area is featured by warm and humid climate， melting glaciers， lake expansion， permafrost degradation， and increasing vegetation cover in CTNR. More importantly， the glacier ablation is one of the main factors leading to the changes in the spatial and temporal distribution of water resources and the water cycle process change， which will undoubtedly exert a profound impact on social and economic development in the Qinghai-Tibet Plateau.