塔里木河流域的气候变化、径流量及人类活动间的相互影响

INTERRELATIONSHIP OF CLIMATE CHANGE, RUNOFF AND HUMAN ACTIVITIES IN TARIM RIVER BASIN

根据塔里木流域 1 3个气象站 ( 1 961～ 2 0 0 0年 )和 8个水文站 ( 1 95 7～ 1 998年 )的观测资料 ,对塔里木河各流域段的气候变化以及沙尘时空分布特征进行了分析 ,建立了相对耗水影响指数 ,试图量化人类活动的强度 ,研究了塔里木河流域各段的气候变化和人类活动对源流径流及生态环境的影响 ,为正确制定塔里木河流域发展战略 ,保护和治理塔里木河流域生态环境提供科学依据。研究结果表明 :( 1 ) 5 0年代以来塔里木河源流的水量并没有多大的变化 ,但最终净入塔里木河干流的水量却明显下降。 ( 2 )相对耗水影响指数表明人类活动影响对中游的影响要远大于上游的影响 ,70～ 80年代中期是人类活动影响最大的时期。( 3) 90年代与多年平均相比 ,塔里木河流域气温增高 ,降水量明显增加 ;从塔里木河源流区到下游区 ,气温增高幅度逐步加大。 ( 4 ) 90年代以来塔里木河各区 ,沙尘暴、浮尘和大风日数均呈明显大幅下降趋势。 ( 5 )塔里木河下游铁干里克的年降水不仅没有增加 ,反而略有下降 ,沙尘暴日数不但没有下降反而上升 ,应该引起人们的注意。

The temporal and spatial characteristics of climate change, dust storms and runoff in all the source areas and the mainstream of the Tarim River are analyzed based on observations in 13 meteorological stations (from 1961 to 2000) and 8 hydrologic stations (from 1957 to 1998) over the Tarim River basin. The water consumption influencing index, which quantifies the impact intensity of human activities, is set up, and the impacts of climate change and human activities on the runoff, even the ecological environment are studied. The results show: (1) Although the runoff over the source areas didn't change obviously since 1950's, but the amount of water entered the mainstream of the river from these source areas obviously decreased, and human activities is the main cause. (2) The water consumption influencing index analysis shows an increasing trend, which reflects the impact of human activities to some degrees, and the impact of human activities in the middle reaches of the river is greater than that in the upper reaches. The impact of human activities was most obvious during the period from the 1970's to the mid 1980's, and slowed down in recent 10 years. (3) In 1990s, temperature and precipitation increased over the river basin. The increasing amplitude of temperature increases from the source areas to the lower reaches of the river. In Aksu (in the source area), the increasing amplitude is the smallest for temperature and the biggest for precipitation. (4) Since the 1990's, the number of dust storm days, the number of floating dust days and the number of strong wind days in the river basin obviously decreased. These changes could be attributed to the extending of oasis. (5) Precipitation at Tiekanlik (at the lower reaches) decreases, instead of increasing, and the number of dust storm days increases. It should be paid attention by the related departments.