Groundwater storage change monitoring in North China Plain based on GNSS and satellite gravity

The North China Plain in China is one of the areas with the scarcest water resources, and it is an area with more groundwater extraction. The form of groundwater in this area is severe, and it is necessary to monitor the changes in groundwater reserves in this area. Traditional use of groundwater wells to monitor changes in groundwater levels makes it difficult to obtain accurate changes in groundwater reserves. GRACE/GRACE-FO satellite gravity has made great achievements in the changes of land water reserves and groundwater reserves, but due to the low spatial resolution, it is not possible to obtain the changes of groundwater reserves in the North China Plain. This paper integrates GNSS and GRACE/GRACE-FO satellite gravity data, based on the load deformation theory, effectively integrates GNSS and satellite gravity data, separates groundwater balance effect and groundwater load impact, obtains the change of groundwater reserves in the North China Plain from 2018 to the end of 2021, and conducts comparative analysis on the observation data of groundwater wells and precipitation data, finding that the downward trend of groundwater level has slowed down, The groundwater reserves in the North China Plain declined as a whole, and the groundwater in some areas of Beijing rose slightly.