南水北调工程对华北平原水储量变化的影响

南水北调工程自2014年底正式通水后对华北平原水储量亏损趋势的影响程度是一个尚未评估的科学问题。基于GRACE及GRACE Follow-on重力卫星观测数据计算华北平原水储量变化，并与南水北调输水量（3.08 Gt/a）进行对比，发现2004-2015年华北平原陆地水储量变化速率为（-5.92±0.53）Gt/a，2015-2019年变化速率有所抬升，变为（-2.96±2.79）Gt/a，表明华北平原陆地水储量亏损速率降低50%，长期亏损趋势得以明显缓解。同时，北京市和天津市的水量亏损趋势也明显改观。因此，南水北调工程显著改善了华北地区水资源紧张的局面，发挥了积极有效的重要作用。

Influence of South-to-North Water Transfer Project on the changes of terrestrial water storage in North China Plain

The impact of the South-to-North Water Transfer Project on the terrestrial water storage (TWS) depletion in the North China Plain since the formal water supply at the end of 2014 has not been evaluated. Based on the data of GRACE and GRACE Follow-on gravity satellites, this paper calculates the changes of water storage in the North China Plain, and compares it with the water amount (3.08 Gt/a) supplied by the South-to-North Water Transfer Project. It is found that the change rate of TWS in the North China Plain from 2004 to 2015 is (-5.92±0.53) Gt/a, and the change rate in 2015-2019 is (-2.96±2.79) Gt/a. The results show that the change rate of TWS was decreased by 50%, and the trend of long-term depletion was alleviated obviously. At the same time, the trend of TWS in Beijing and Tianjin has also changed significantly. Therefore, the South-to-North Water Transfer Project had significantly improved the situation of TWS in North China, and played an active and effective role.