摘要
西北干旱区是对全球变化响应最敏感的地区之一,"气候变化对西北干旱区水循环影响机理与水资源安全研究"项目,以全球变化背景下的西北干旱区气候-水文过程、水循环机理、水资源形成与转化以及未来变化趋势为主线,重建了过去300年西北干旱区气候变化序列,分析了气候变化对水循环关键过程和水系统的影响,构建了适合山盆地貌格局的水文、水资源模型,分析了未来水资源变化趋势,得出了一系列有意义的结论:在过去300年间,西北干旱区以冷干、暖湿气候类型交替出现,存在40年的变化周期;在近50年,温度、降水出现了"突变型"升高,自1997年以来,升温滞缓,处于高位震荡;蒸发潜力由显著下降逆转为显著上升趋势,水循环过程加剧;极端气候水文事件频度增强、频率加大,水文波动性增强、水资源不确定性增大;天山山区冰川加速退缩,冰雪水储量呈减少态势,部分河流出现冰川消融拐点;水系统安全性降低,供需水矛盾会进一步加剧;伴随气温的高位震荡和地下水的超采,西北干旱区的生态隐忧和潜在风险加大。
The arid region of Northwest China is a special natural unit, which responds sensitively to the global cli- mate change. The project of ＂Impacts of climate change on the water cycle mechanism and water resources secu- rity in the arid region of Northwest China＂ focused on the key issues of climate-hydrological processes, mecha- nism of water formation and transformation, and its re- sponses to climate change; reconstruction of the climate change series during the past 300 years, hydrological and water resources model, and estimation of future trends in water resources. The main findings are as fol- lows ： （ 1 ） the cold-dry and warm-wet climate types ap- peared alternately during the past 300 years, which has about 40 years cycle. （2） The air temperature and pre- cipitation in the arid region of northwest China had a significant step increasing trend in the past 50 years, however, the sharp increasing trend has retard since 1997. （3） Pan evaporation in the region exhibited an obvious decreasing trend until early 1990s, and then re- versed to upward, the water cycle is intensifying. （4） The frequency of climate and hydrological extreme events increased ; also the uncertainty of water resources has increased. （5） The glacier change has exerted great impact on water resources, and many rivers have passed the ＂Glacier inflexion＂ ; also the water storage decreased in the Tianshan Mountains. （6） Water sys- tem security has reduced the contradictions of water supply and demand will be intensified. （7） the negative effects on ecology have been highlighted. In the future, the water crisis in the eastern in this region will be ex- acerbated.
出处
《中国基础科学》
2015年第2期15-21,F0002,共8页
China Basic Science
基金
全球变化研究国家重大科学研究计划(2010CB951000)
关键词
气候变化
水循环
冰川退缩
径流分割
极端事件
climate change
water cycle
glacial reces-sion
runoff and base flow separation
extreme events
