Gravity Recovery and Climate Experiment (GRACE) data with other data sets are used to estimate the mass variations over the Eastern Desert. These variations are caused by changes in terrestrial water storage (ΔTWS). Monthly GRACE and Mascon Solutions with other relevant data are conducted. Findings are (1) the Eastern Desert is witnessing a dry climatic period (April 2002 to July 2012) with lower average annual precipitation (AAP) rate of 9.3 mm and a wet climatic period (August 2012 to July 2016) with slightly higher precipitation rate of 14.1 mm; (2) the average trends in ΔTWS over the study area are estimated at − 4.40 ± 0.63 mm/year and + 4.37 ± 20.7 mm/year during the dry and wet periods, respectively; (3) the spatial distribution of the ΔTWS values during the wet period are consistent with the distribution of the rainfall, and the water leakage from Lake Nasser towards the surroundings though fault conduits; (4) the groundwater storage variation (ΔGWS) shows a negative trend of − 3.95 ± 0.63 mm/year during the dry period, while it shows a positive trend of + 4.98 ± 2.00 mm/year for the wet period; (5) Lake Nasser shows slightly higher water level variations during the wet period, in comparison to that of the dry period; (6) the surface water is draining eastward into the Red Sea and westward into the Nile River and partially feeding the underground aquifers through the permeable outcrops and/or along the sub-vertical deep-seated faults. Results provide new information on the mass variations of the Eastern Desert, caused by the change in the water storage in response to the climatic variation and global warming. The lowlands of the main valleys may represent the promising areas for agricultural development in the Eastern Desert.

An integrated approach of Gravity Recovery and Climate Experiment (GRACE) and vertical electrical resistivity sounding (VES) technique has been carried out to investigate regionally and locally the groundwater potentialities of Wadi Sar in the Hijaz Mountains. Our findings are (1) the terrestrial water storage variations (ΔTWS) are estimated at −2.06±0.34 mm/year; (2) the Global Land Data Assimilation System–derived soil moisture storage variations (ΔSMS) are estimated at −0.067±0.005 mm/year; (3) the groundwater storage variations (ΔGWS) show a negative trend estimated at −2.00±0.34 mm/year during the period April 2002–July 2017; and (4) the average annual precipitation (AAP) rate is estimated at 115 mm during the period 2002–2018. Three geoelectrical layers are identified from the inversion of the electrical resistivity data: (5) the surface layer of high resistivity values is consisted of dry unconsolidated Quaternary deposits; (6) the second layer represents the fractured groundwater aquifer of low resistivity values and variable thickness; (7) the third layer is composed of fractured basement rocks of higher resistivity values. The streams are draining the surface water toward the Najd Pedi plain aquifer; (8) the faults are acting as conduits for groundwater flow away from the Wadi. The current study indicates the occurrence of groundwater at the downstream zones of the Wadi Sar, but with a general decrease trend. The integrated approach provides a better understanding of the groundwater potentialities in the arid regions.