A review of satellite-based monitoring of groundwater storage changes and depletion consequences

Abstract

Groundwater demand is increasing due to global population growth, climate change and rapid urbanization, however, poor planning and over-exploitation are leading to rapid depletion of groundwater, which in turn causes adverse impacts such as land subsidence, soil salinization and water quality deterioration. Groundwater storage (GWS) monitoring is essential to the sustainable management of regional water resources and the prevention of environmental and social issues associated with depleted groundwater resources. Conventional groundwater observation is primarily conducted through groundwater well-level measurements, which requires a lot of time and effort, and is insufficient to accurately reflect GWS changes regionally and monitor large-scale groundwater level changes. The availability of various satellite data makes it easier to study groundwater information effectively. The aim of this paper is to first review the seriousness of groundwater depletion, every year, 15% to 25% of the total global groundwater extraction is overexploited. Then, based on satellite geodetic technologies such as Gravity Restoration and Climate Experiment (GRACE), GRACE Follow-On, Sentinel-1, and Global Navigation Satellite System (GNSS), the basic principles of GWS monitoring are expounded. The reliability of the monitoring results was analyzed through the literature summary, showing that the results were basically consistent with the trends reflected by the measured groundwater samples, and the statistical significance of quantitative comparisons was higher than 0.65. The impact of the consequences of groundwater depletion also deserves our attention. This paper combined with multi-source satellite and tidal data, etc., the feasible research methods are discussed for a series of adverse consequences caused by groundwater depletion.