近50年来塔里木盆地南、北缘干湿状况变化趋势分析

全球变暖大背景下,塔里木盆地边缘绿洲气候变化趋势研究已成为研究的热点。文中利用塔里木盆地南、北缘17个典型绿洲气象站1959-2008年的气象资料,使用联合国粮农组织(FAO)推荐的Penman-Monteith公式,计算近50年潜在蒸散量,定义了地表干燥度指数。在此基础上,对塔里木盆地南、北缘,近50年气候变化特征及其成因进行对比分析。结果表明:塔里木盆地南、北缘气候变化与全球气候变化趋势基本一致,但又具有明显的区域性特点:塔里木盆地南、北缘潜在蒸散量均在波动中呈减少趋势,南缘递减速度比北缘快;干燥度指数也均在波动中呈缓慢减小趋势,其中南缘干燥度指数递减速度比北缘快;总之塔里木盆地南、北缘绿洲有缓慢向暖湿转化的迹象,这对气候极端干燥的塔里木盆地边缘绿洲生态环境的改善和农业生产有积极的影响。

The variation trend of surface dry-wet conditions in recent 50 years in the southern and northern edge of Tarim Basin

On the background of global warming,study the climate change trends about the oasis of Tarim Basin edge has become a hot topic.Based on the climatic data observed by 17 meteorological stations in the southern and northern edge of Tarim Basin during the period of 1959-2008,the potential evapotranspiration at all the stations were calculated with the Penman-Monteith equation recommended by FAO in 1998,and the change characteristics of aridity index were compared with that in the southern and northern edge of Tarim Basin.The results show that the trend of climate change in the southern and northern edge of Tarim Basin was basically the same with that in China and even in the world.However,some obvious regional characteristics existed,in the recent 50 years,the change trend of potential evapotranspiration in the southern and northern edge of Tarim Basin were similar,both have a decreasing trend,But the average value and linear digression speed of potential evapotranspiration in the southern margin of Tarim Basin were higher than the northern part.The change trends of aridity index in the southern and northern edge of Tarim Basin both had a decreasing trend.From the change of the annual evapotranspiration and the aridity index in the southern and northern edge of Tarim Basin,we can see that the signals of climate wetting have occurred.This will have a positive effect on the improvement of ecological environment and agricultural in these extremely dry climate oasis.