Spatio-Temporal Dynamics of Groundwater Storage in Pakistan from Gravimetric Observations

Abstract Groundwater is the predominant water source in Pakistan, meeting the needs of industry, agriculture, and households. This study investigates groundwater storage variations in Pakistan and mainly focus at the provincial levels from 2003 to 2022 using Gravity Recovery and Climate Experiment (GRACE) observed terrestrial water storage anomalies (TWSA) and water storage components from Global Land Data Assimilation System (GLDAS). The analysis reveals significant fluctuations in groundwater storage levels, influenced by various factors, including seasonal changes in precipitation and agricultural activities. The study highlights substantial decline in groundwater storage over the last decade. The spatial analysis uncovers uneven patterns of groundwater storage variations across the country. Punjab and Sindh provinces are notable for their distinct and significant changes, including declines and slightly increases, respectively, compared to other regions. These findings underscore the importance of sustainable groundwater management practices, particularly in provinces and regions with heightened extraction rates and susceptibility to drought and flood events. Floods significantly increase groundwater recharge, while drought-affected areas show noticeable decreases in groundwater storage. This research contributes to a better understanding of Pakistan's groundwater dynamics. It emphasizes the need for effective policies to ensure long-term water resource sustainability in changing climate conditions and human activities.