青藏高原水资源演变与趋势分析

Evolution and Trend of Water Resources in Qinghai-Tibet Plateau

青藏高原及周边地区是长江、黄河、雅鲁藏布江等河流的发源地,素有“亚洲水塔”之称。分析青藏高原地表水、地下水资源量的演变规律和与变化趋势,对青藏高原水资源及水生态保护以及区域发展具有重要战略意义和科学价值。基于河流源区主要江河水文站实测径流资料分析发现,由于降水增多、气温升高等气候变化的影响,青藏高原多数区域地表河川径流量呈现增加趋势,季节过程也发生了明显变化,长江、怒江和雅鲁藏布江河源区径流增加趋势尤为显著。研究发现,气温升高导致的冰川积雪融化径流的增多是地下水资源量以及高原湖泊水量增加的主要原因。未来预测分析认为,随着冰川积雪的减少,融雪径流将会减少,部分河流径流量会出现由增转减的“拐点”,这将导致该区域的水资源安全面临新的问题和挑战。全球变化对青藏高原水资源演变的影响需引起高度重视,并积极采取应对措施。

The Qinghai-Tibet Plateau is the source of major Asian rivers such as the Yangtze River,the Yellow River,and the Yarlung Zangbo River,which is known as Asia’s water tower.Analysis on the evolution rule and variation trend of surface water and groundwater resources in the Qinghai-Tibet Plateau is of great strategic and scientific importance to the water resources,water ecological protection,and future regional development of the Qinghai-Tibet Plateau.Based on the analysis of the observed runoff series of hydrological stations in the main rivers within source areas,it is found that the surface runoffs in most areas of the Qinghai-Tibet Plateau show an increasing trend impacted by climate change in terms of more precipitation and rising temperature,and indicates significant changes in seasonal processes.The runoffs increase more significantly in the source areas of the Yangtze,Nujiang,and Yarlung Zangbo rivers.The results demonstrate that the dominant factor is increased glacier and snow melting flow to more groundwater and growth of plateau lakes,due to temperature rising.With the depletion of glacier and snowpack,the melting water will be reduced in future.Therefore,the break point of increase to decrease will arise in some river runoffs.Thus,the water security of this region will face new problems and challenges.High attention should be paid to the global change impact to water resources evolution in the Qinghai-Tibet Plateau,and positive responsive measures should be taken.