近20年青藏高原水资源时空变化

青藏高原被称为“亚洲水塔”和“第三极”,青藏高原水资源变化对我国乃至周边众多国家的水资源安全及人民生活均产生深远的影响。利用《青海省水资源公报》及《西藏水资源公报》数据,采用线性倾向估计、Mann-Kendall趋势检验法和Person相关系数法对1997—2018年青藏高原地表及地下水资源时空变化进行了研究。结果表明:①青藏高原水资源分布呈东多西少、南多北少的分布态势,水资源分布极其集中,主要集中在山南、林芝市,雅鲁藏布江流域及藏南诸河流域。②1997—2018年青藏高原地表水资源量呈不显著的上升趋势,地下水资源量呈显著下降趋势(－166.4亿m³／(10 a))。水资源变化趋势存在显著的空间差异,青藏高原北部青海省大部分地区地表水资源(98.3亿m³／(10 a))及地下水资源量(58.0亿m³／(10 a))均呈显著的上升趋势,南部西藏自治区大部分地区地表水资源量呈不显著的下降趋势,地下水资源量呈显著的下降趋势(－195.4亿m³／(10 a))。③青藏高原近年来气温呈十分显著的增加趋势,上升速率约为0.49 ℃／(10 a),北部青海省降水量呈显著增加趋势,南部呈不显著的下降趋势。综合降水与气温的影响,降水量变化是青藏高原地表水资源与地下水资源变化的主要影响因素。

Spatial and Temporal Characteristics of Water Resources in Qinghai-Tibet Plateau in Recent Two Decades

The Qinghai-Tibet Plateau is renowned as the water tower of Asia and the third pole of the world. Changes in the water resources of the Qinghai-Tibet Plateau has a profound impact on the water resources security and people’s lives in China and its neighboring countries. The temporal and spatial changes of surface and groundwater resources in the Qinghai-Tibet Plateau from 1997 to 2018 are studied using linear tendency estimation, Mann-Kendall trend test and Pearson correlation coefficient method based on the data of Qinghai Water Resources Bulletin and Tibet Water Resources Bulletin. The results of the study indicate that: (1) water resources in the Qinghai-Tibet Plateau is extremely concentrated, mainly in Shannan, Nyingchi City, the Yarlung Zangbo River Basin and the river basins of southern Tibet. The south and east of Qinghai-Tibet Plateau boasts abundant water resources while the north and the west less. (2) From 1997 to 2018, the amount of surface water resources on the Qinghai-Tibet Plateau showed an insignificant upward trend, while the amount of groundwater resources (-16.64 billion m³/(10 a)) a significant downward trend. The change trends of water resources differed notably in spatial scale, with the surface water resources (9.83 billion m³/(10 a)) and groundwater resources (5.8 billion m³/(10 a)) in most areas of Qinghai Province in north Qinghai-Tibet Plateau displaying a significant upward trend, and surface water resources in most parts of the southern Tibet Autonomous Region an insignificant downward trend, groundwater resources a significant downward trend (-19.54 billion m³/(10 a)). (3) In recent years, the temperature in Qinghai-Tibet Plateau has had a very significant increasing trend, with the rising rate reaching 0.49 ℃/(10 a). The precipitation of Qinghai Province in the northern part of the Qinghai-Tibet Plateau showed a significant increase trend, while the southern part an insignificant downward trend. In conclusion, precipitation is the major factor that induces the changes of surface water resources and groundwater resources in the Qinghai-Tibet Plateau.