青藏高原可可西里盐湖水量平衡初步分析

Preliminary study on water balance for Salt Lake in Hoh Xil, Tibetan Plateau

可可西里地区主要湖泊自西向东分别为卓乃湖、库赛湖、海丁诺尔湖和盐湖。2011年9月自卓乃湖溃决后,大量湖水外泄,导致原本独立的4个湖泊建立了水力联系,盐湖成为最下游的尾闾湖,水文情势发生变化。利用周边地面监测站点及多次水文调查,统计分析了1961~2018年可可西里主要气候要素变化趋势,并从水量平衡角度探讨了水文情势变化后的盐湖水体补排、泄、蓄关系。结果表明:2011年之前,盐湖为独立的补排关系;2011年之后,由于青藏高原暖湿化变化,上游卓乃湖、库赛湖、海丁诺尔湖已相继蓄满,多余水量全部进入盐湖,导致其持续扩张。若盐湖水位持续上涨,湖水将外溢进入长江流域楚玛尔河支流清水河,对青藏多条“生命线”构成威胁。

Zhuonai Lake,Kusai Lake,Haidingnuoer Lake and Salt Lake are located from west to east in Hoh Xil region,Tibetan Plateau.In September 2011,a large amount of water overflowed from the Zhuonai Lake due to embankment break.After that,these isolated lakes were then connected.Salt Lake had become the terminal lake and its hydrologic regimes had also changed accordingly.On the basis of the data obtained from monitoring stations and hydrographic survey,the climate change trend during 1961~2018 in Hoh Xil region were analyzed in this paper.Furthermore,the relationship between recharge,discharge and storage after hydrologic regimes change in the Salt Lake were explored from the perspective of water balance.It was found that before 2011,there was independent relationship between recharge and discharge in the Salt Lake.After 2011,Zhuonai Lake,Kusai Lake and Haidingnuoer Lake in the upstream region exceeded storage capacity due to a warmer and moister atmosphere in the Tibetan plateau.Therefore,the Salt Lake stored the overflow from these lakes,resulting in the Salt Lake expansion.If the water level of the Salt Lake keeps rising,the water will overflow from it and flow into the Qingshui River,a tributary of the Chumar River in the Yangtze River Basin,which is a threat to Qinghai-Tibetan Highway.