基于GRACE和GLDAS的河南省2003—2022年地下水储量变化研究

Study on groundwater storage changes in Henan province during 2003—2022 derived from GRACE and GLDAS

河南省是中国水资源相对短缺严重的地区之一,地下水的过度消耗已成为制约该地区经济社会发展和生态环境保护的重要因素。本文基于2003—2022年GRACE、GRACE-FO卫星重力数据及GLDAS陆面同化数据,采用奇异谱插值法和时序分解法,分析了河南省近20年地下水储量的时空变化特征及影响因素。结果表明:河南省近20年地下水呈“V”形变化特征,变化速率呈现由西南至东北逐渐递减的阶梯式分布;2015年前后变化速率分别为-15.53、8.88 mm/a,东北部地区地下水由亏损转为盈余状态;对比反演结果与降水和南水北调中线工程调水数据发现,降水与地下水变化密切相关,但不是地下水长期下降的主要原因;通过南水北调工程异地调配地表水供给受水区生产生活用水而置换地下水抽采,有效缓解了地下水亏损,是地下水止跌回升的重要影响因素。本文研究结果为了解近20年河南省地下水储量的时空变化规律及更好发挥南水北调工程调水作用提供了参考依据。

Henan province is one of the regions in China with relatively severe water scarcity.The excessive consumption of groundwater has become an important factor restricting the economic and social development and ecological environment protection in the region.Based on GRACE,GRACE-FO satellite gravity data,and GLDAS land surface assimilation data from 2003 to 2022,this study analyzes the temporal and spatial changes of groundwater reserves in Henan province over the past 20 years using singular spectrum interpolation and time series decomposition methods,as well as the influencing factors.The results show that the variation of groundwater reserves in Henan province over the past 20 years shows a V-shaped trend,with the rate of change decreasing stepwise from the southwest to the northeast.The rate of change before and after 2015 is-15.53 and 8.88 mm/a,respectively,and the groundwater in the northeastern region has shifted from deficit to surplus.A comparison of the inversion results with precipitation and water transfer data from the south-to-north water transfer project reveals that precipitation is closely related to the change in groundwater,but it is not the main reason for the long-term decline in groundwater.The replacement of groundwater pumping by deploying surface water for production and living in the receiving area through the south-to-north water transfer project effectively alleviates the groundwater deficit,playing a crucial role in groundwater recovery.The study results provide an important reference for understanding the spatial and temporal changes of groundwater reserves in Henan province over the past 20 years and for better leveraging the role of the south-to-north water transfer project in water management.