Research on the spatiotemporal variation of groundwater storage in the Ordos Basin based on GRACE gravity satellite data

The series of environmental issues caused by the decline in groundwater level have significantly impacted social development. The Ordos Basin, one of the largest groundwater basins in the world, faces water scarcity, with groundwater being its primary water resource. Therefore, analyzing the spatiotemporal variation of groundwater storage is of great significance. This study focuses on the Ordos Basin and utilizes GRACE gravity satellite data and GLDAS model data, employing methods such as the generalized inverse distance weighting, adf test, and wavelet analysis to investigate the spatiotemporal variation of groundwater storage in the basin. The results indicate the following: (1) Before 2008, climate had a significant influence on groundwater storage in the Ordos Basin, with minimal impact from human activities. (2) Starting from 2008, human activities have caused a noticeable decline in groundwater storage, particularly in the eastern region. (3) Human activities primarily affect groundwater in the saturated zone, while their impact on soil water in the unsaturated zone is relatively small. (4) Human activities have altered the natural cyclical relationship between precipitation and groundwater storage, leading to an increasingly complex relationship between the two. The research findings highlight that human activities are the main factor driving the variation in groundwater storage in the Ordos Basin and provide crucial scientific support for the protection of groundwater resources.