Evaluation of the dynamic variations of groundwater utilizing GRACE data for the dammam aquifer within muthanna governorate, Iraq

Recently, the worldwide drought situation has gotten worse and is posing a serious threat to many nations, including Iraq. It is now unavoidable to use modern technologies, including remote sensing, to lessen the effects of this catastrophe. This paper aims to check the consistency of groundwater storage (GWS) derived from multiple sources utilizing remote sensing data with direct measurements in wells in the Dammam unconfined aquifer, which is situated in Al-Muthanna Governorate, Iraq. This study utilizes the water-level readings from well records from January 2008 to December 2014. The groundwater results from different combinations of Gravity Recovery and Climate Experiment (GRACE) products, Goddard Space Flight Center (GSFC) mascon, Jet Propulsion Laboratory Downscaled (JPLD), and Catchment Land Surface Model (CLSM), are calibrated and validated using statistical analysis. The findings illustrate large GWS depletion rates of GWS_W, GWS_JPLD, and GWS_GSFC at -54∓10 mm/yr, -11∓5 mm/yr, -6∓5 mm/yr, respectively. The Pearson, Spearman, and Kendall correlation reaches 0.93, 0.96, and 0.90 with a P-value less than 0.05. The highest coefficient of determination (R2) was 0.93 for GWS_GSFC, and the lowest was 0.42 for GWS_JPLD. The finding of classification of the GSFC and JPL data indicated that the GWS agrees with the spatial and temporal distributions of the highest depletion in the Dammam Aquifer. The study demonstrated that GRACE estimations can accurately reflect monthly variations in groundwater stocks, making them a valuable tool for resource managers to assess the water situation and plan sustainable water use.