Quantification of Long-Term Groundwater Storage Change in Transboundary Aquifers of Indus River Basin in India Using Remotely Sensed Data

Groundwater overexploitation in the Indus Basin transboundary aquifers has a significant implication for water security in South Asia. To measure changes in groundwater storage in these aquifers over a given time frame, Gravity Recovery and Climate Experiment (GRACE) satellite data has been utilized to provide estimates of Terrestrial Water Storage (TWS) anomalies and its Spatial-temporal variation. GRACE-derived data of TWS for the Indus River Basin area from 200 to 2024 was used for the present investigation. Rescaling method is used to resample the GRACE data, and uncertainty is determined to minimize error and increase accuracy. The monthly long-term variation in TWS has been observed for the entire Indus River basin and compared with field ground water level data. Soil moisture data, Global Land Data Assimilation System (GLDAS), has also been utilized to compute groundwater storage time series data and their uncertainty. The result shows that most of the aquifers in the Indus River Basin have been over exploited due to excessive irrigation from ground water. The study concludes that if the rate of extraction of ground water remains constant are increases, then aquifer would be vulnerable considering the changing climate pattern and increasing demand for irrigation from ground water resources.