摘要
基于土地荒漠化的涵义 ,以及塔里木河流域的人类活动特点和流域水系的组成状况 ,选择了 2 6个与水系组成相关的气象台站 1 961～ 2 0 0 0年的年降水量、夏半年 ( 5～ 1 0月 )月均气温的资料 ,对近 40年来该区域土地荒漠化发展的气候背景和时空变异特征进行了分析。年降水量的分析结果表明 ,流域平均年降水量为 77mm ,年降水量年际变化较稳定 ,变异系数为 0 5 0 ;40年来各水系的年降水量普遍呈增加趋势 ;年降水量的空间差异较大 ,差异系数多年平均为 2 2 9。气温的分析结果表明 ,流域多年平均气温为 2 0℃ ,气温年际之间变化微弱 ,变异系数为 0 0 3;从气温的变化趋势来看 ,流域各水系的增降趋势不同步 ,其中叶尔羌河流域和干流上游的气温表现为下降趋势 ,其他各水系为增温趋势 ;气温空间差异较小 ,多年平均为 0 2 1。近 40年降水和气温的空间差异具有缩小的趋势。
The climate condition and variability in desertification area are studied based on the data of annual precipitation and summer half-year temperature (May—October) in 26 meteorological stations (25 for temperature) which are selected according to the traits of human activities and the framework of water system in the Tarim River basin. The coefficient of variance (C v) is used in studying the difference/variability of climate factor. The average precipitation is 77 mm and C v is 0.50 in 1961—2000. This shows that the interannual change of precipitation is smaller and stable. The annual precipitation processes indicates the increasing widely tendency in the Tarim River basin in the past 40 years. The average temperature is 20℃ and C v is 0.03 in summer half year in 1961—2000. It shows that the interannual change of temperature is very small and stable. But the increasing and descending tendency of the temperature for all stations are not identical and their amplitudes are very small. The Yarkant River is descending, and others are increasing. The change trends of the precipitation and temperature show that the characteristic of climate change is wet type. Generally, this change can produce the positive influence on the eco-environment. Spatial C v of precipitation is large, average is 2.29. spatial C v of temperature is small, average is 0.21. These two spatial C vs are descending trends. All these state that the provoking effect of climate factor is weak in rapidly desertification evolution in the Tarim River basin in the past 40 years. But climate factor is an important background condition of desertification, and its function is persistent and stable.
出处
《气候与环境研究》
CSCD
2004年第4期658-669,共12页
Climatic and Environmental Research
基金
国家重点基础研究发展规划项目G1 9990 43 5 0 5和G1 9990 43 5 0 9资助
关键词
塔里木河流域
气候变化
土地荒漠化
生态环境
时空变异
Tarim River basin
climate change
desertification
eco-environment
spatial-temporal variability
