近50a西北干旱区气候变化趋势及对荒漠化的影响

西北干旱区干旱少雨,生态环境脆弱,土地荒漠化严重。本文根据近1951-2000年的逐月平均气温和月降水量资料研究了我国西北干旱区气候变化趋势,并结合近年来西北干旱区地表径流量变化,分析其对准噶尔盆地、塔里木盆地、河西走廊和柴达木盆地土地荒漠化影响。研究结果表明:(1)近50a西北干旱区气温都升高,变暖最显著的是北疆和柴达木盆地。降水量有增加趋势,其中南疆降水量增加趋势最大。北疆蒸发量有减少趋势外,其他区蒸发量都在增加,尤其南疆蒸发量增加趋势最大。(2)近50a来由于气候变暖,使蒸发量增大,塔克拉马干沙漠、河西走廊沙漠区和柴达木沙漠区的干旱危害加剧,这必然导致沙漠化的易发和其进程的加速。北疆气温升高,降水量增加,而蒸发量减少,有利于古尔班通古特沙漠区沙漠化进程的减缓。(3)气候变化和地表径流量变化有利于准噶尔盆地和塔里木盆地的土地荒漠化逆转,而使河西走廊和柴达木盆地的土地荒漠化发展迅速。

Climate Change and Surface Runoff Change Impact on Desertification in the Arid Area of Northwest China in Resent 50 Years

Based on the monthly mean temperature and precipitation data of 21 stations in resent 50 years,the trends of climate change and variation of surface runoff change were studied and analyzed in order to know theirinfluence on desertificationin Junggar Basin,Tarim Basin,Hexi Corridor and Qaidam Basin.The results showed that in the arid area of Northwest China in resent 50 years,temperature was increasing,remarkable warming in the northern Xinjiang and Qaidam Basin.Precipitation was increasing,and obvious in the southern Xinjiang.Evaporation all were increasing except in the northern Xinjiang,especially in the southern Xinjiang.(2) Evaporation was increased due toclimate warming inresent 50 years.Taklmakan Desert,deserts of Hexi Corridor and Qaidam Basin were much moredrought,which resulted in accelerative desertificationcourse.Warming climate,increased precipitation and decreased evaporation in the northern Xinjiang were in favor of slowdownof desertification Gurbantonggut Desert.(3) Climate change and surface runoff change were in favor of desertification reversionof Junggar Basin and Tarim Basin,but their change would accelerate the development of desertificationin Hexi Corridor and Qaidam Basin.