Missing water from the Qiangtang Basin on the Tibetan Plateau
Missing water from the Qiangtang Basin on the Tibetan Plateau
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DOI：
10.1002/essoar.10503444.1
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发表时间：
2020-06
期刊：
影响因子：
5.8
通讯作者：
Bin Yong;Chi‐yuen Wang;Jiansheng Chen;Jiaqi Chen;Tao Wang;Ling Li;D. Barry
中科院分区：
文献类型：
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作者：
Bin Yong;Chi‐yuen Wang;Jiansheng Chen;Jiaqi Chen;Tao Wang;Ling Li;D. Barry
羌塘盆地是青藏高原内部的一个大型内陆盆地，与周围湿润的外部地区相比，一直被认为是一个干旱地区，为亚洲所有主要河流提供水源。结合2002年至2016年的地表水文数据、建模和卫星数据，我们的研究表明，羌塘盆地每年有大量的水资源（约54 ± 4 km3）未被计算在内。失踪水量与黄河年总流量相当。重力恢复和气候实验（GRACE）卫星使命任务的数据显示，当地陆地水储存量几乎没有增加。因此，失踪的水必须通过地下通道流出盆地。根据最近对西藏的地震和地质研究解释这一结果，我们认为，羌塘盆地大量的大气降水是通过地下水流通过深正断层和张性断裂沿着近南北向的裂谷渗漏出来的，这些裂谷的方向低于盆地南缘的地表水文分水岭。如此大规模的跨流域地下水外流违背了流域尺度水循环的传统观点，并导致与以前的羌塘流域水文观点截然不同的画面。这一发现要求对区域水平衡进行重大反思。
The Qiangtang Basin is a large endorheic basin in the inner part of the Tibetan Plateau, and has been thought to be a dry region in contrast with the surrounding wet outer region that feeds all the major Asian rivers. Combining surface hydrological data with modeling and satellite data from 2002 to 2016 CE, our study reveals that an enormous amount of water, ~54 ± 4 km3, is unaccounted for annually in the Qiangtang Basin. The amount of missing water is comparable to the total annual discharge of the Yellow River. Data from the Gravity Recovery and Climate Experiment (GRACE) satellite mission show little increase of local terrestrial water storage. Thus, the missing water must have flowed out of the basin through underground passages. Interpreting this result in the context of recent seismic and geological studies of Tibet, we suggest that a significant amount of meteoric water in the Qiangtang Basin leaks out by way of groundwater flow through deep normal faults and tensional fractures along the nearly north-south rift valleys that are oriented subnormal to and cross the surficial hydrological divide on the southern margin of the basin. Cross-basin groundwater outflow of such a magnitude defies the traditional view of a basin-scale water cycle and leads to a very different picture from the previous hydrological view of the Qiangtang Basin. This finding calls for major rethinking of the regional water balance.