基于GRACE数据的黄河流域地下水储量变化与人口暴露研究

近年来黄河流域人与水资源矛盾愈发突出，尤其是地下水储量的过度消耗已成为限制该区域人与自然和谐发展的主要矛盾之一。基于重力反演与气候实验卫星数据和全球陆面数据同化系数数据，根据流域水循环与水量平衡原理，测算2003—2016年黄河流域地下水储量的变化情况，在探究其时空变化特征的基础上，识别了地下水储量下降明显区域的人口暴露度。结果表明：（1） 空间分布上，黄河流域地下水储量西多东少，由西向东下降程度不断加剧，且下降区域呈现由下游向中上游扩散的态势。下降区域主要集中在中东部地区，变化等级以较剧烈减少和剧烈减少为主。（2） 时间变化上，2003—2016年黄河流域地下水储量整体呈下降趋势，年均降幅为5.93 mm·a^-1。其中，2004—2016年为连续下降，2015—2016年的下降幅度最大；另外，地下水储量时间变化存在季节效应，地下水储量下降幅度春季最大、冬季次之、秋季再次之、夏季最小。（3） 地下水暴露风险状态下的地级市人口密度在空间上呈东高西低、中部交错分布的状态，暴露风险人口密度最大地级市共16个；地下水储量下降人口累积百分比呈现明显上升的趋势，在2016年达到最大值。研究结果以期为黄河流域地下水资源可持续利用提供科学参考。

Groundwater storage and population exposure in the Yellow River Basin based on GRACE data

In recent years, the contradiction between humans and water resources in the Yellow River Basin,China has become increasingly prominent, particularly the excessive consumption of groundwater has become one of the main contradictions restricting the harmonious development of humans and nature in this region. Based on GRACE satellite data and GLDAS data, the change in groundwater storage of the Yellow River Basin was calculated from 2003 to 2016, then its temporal and spatial characteristics were explored, and population exposure in areas with significant groundwater decline was identified. The results show the following: (1) In terms of spatial distribution, the groundwater storage of the Yellow River Basin are more in the west and less in the east, the degree of decline from the west to east continues to intensify, and the decline area shows a spreading trend from the lower reaches to the middle and upper reaches. (2) The groundwater storage showed a downward trend in the Yellow River Basin from 2003 to 2016, with an average annual decrease of 5.93 mm·a^?1. It is a continuous decline from 2004 to 2016, and the biggest drop occurs in 2015—2016. In addition, there is a seasonal effect on the time change of groundwater storage, groundwater storage declines the most in spring, the second most in winter, the third most in autumn, and the least in summer. (3) Based on the risk of groundwater exposure, the characteristics of population density of prefecture-level cities are high in the east, low in the west, and have a staggered distribution in the middle, and there are 16 prefecture-level cities with the highest population density at risk of exposure. The cumulative percentage of the population with groundwater storage decline exhibited a clear upward trend, reaching a maximum in 2016. The results provide scientific reference for sustainable utilization of groundwater resources in the Yellow River Basin.