Spatiotemporal Analysis of Climate Change Impacts on Groundwater Depletion in Kalar District Using GRACE Satellite Data (2003-2024)

Abstract

Climate change and human activities have led to excessive depletion of groundwater resources in semi-arid areas. This paper explores the fluctuation in the amount of groundwater stored in the Kalar district by analyzing the GRACE data for 21 years through remote sensing technology. The results obtained demonstrate a sharp decrease. The GWSA decreased from -140 mm in 2003 to its record low of -724 mm in September 2024, indicating a yearly average rate of loss of -27.8 mm per year. It shows that over-exploitation is taking place, worsened by climate change. Additionally, soil water storage levels have been maintained on a seasonal basis, but it is only the underground water that suffers losses. Importantly, even the unexpected rainfall witnessed in 2019 did not alter the trend. These observations point to the necessity of shifting from reactive approaches to proactive adaptive strategies in water management systems. The main problem of this study is the great threat facing groundwater resources in the region and Kalar district. To understand this crisis, this study attempts to answer the following three key questions: To what extent have climate change and anthropogenic pressures (such as over-extraction of water), affected the decline in groundwater levels (GWSA) in Kalar district? . . . . Are there differences between surface soil moisture (SWS) changes with shallow groundwater reservoirs in the study area? Is the rate of groundwater level decline uniform in all areas of Kalar district, or do hotspots exist in certain areas?