Aquifer recharge, depletion, and connectivity: Inferences from GRACE, land surface models, and geochemical and geophysical data
We used data from the Gravity Recovery and Climate Experiment (GRACE) and outputs of the CLM4.5 model to estimate recharge and depletion rates for large aquifers, investigate the connectivity of an aquifer's subbasins, and identify barriers and preferred pathways for groundwater flow within an aquifer system. The Nubian Sandstone Aquifer System and its subbasins (Dakhla, Northern Sudan Platform, and Kufra) in northeast Africa were used for demonstration purposes, and findings were tested and verified against geological, geophysical, remote sensing, geochronologic, and geochemical data. There are four major findings. (1) The average annual precipitation data over recharge areas in the southern Kufra section and the Northern Sudan Platform subbasin were estimated at 54.8 km 3, and 32.8 km 3, respectively, and knowing the annual extraction rates over these two areas (similar to 0.40 ± 0.20 km 3), recharge rates were estimated at 0.78 ± 0.49 km 3/yr and 1.44 ± 0.42 km 3/yr, respectively. (2) GRACEderived groundwater depletion rates over the Dakhla subbasin and the Northern Kufra section were estimated at 4.44 ± 0.42 km 3/yr and 0.48 ± 0.32 km 3/yr, respectively. (3) The observed depletion in the southern parts of the Dakhla subbasin is apparently caused by the presencemore »
- Western Michigan Univ., Kalamazoo MI (United States). Dept. of Geosciences; Assiut Univ. (Egypt). Geology Dept.
- Western Michigan Univ., Kalamazoo MI (United States). Dept. of Geosciences
- Western Michigan Univ., Kalamazoo MI (United States). Dept. of Geosciences; Suez Canal Univ., Ismailia (Egypt). Geology Dept.
- Argonne National Lab. (ANL), Argonne, IL (United States). Environmental Science Division
- Assiut Univ. (Egypt). Geology Dept.
- Publication Date:
- Grant/Contract Number:
- AC02-06CH11357; 2000007141
- Accepted Manuscript
- Journal Name:
- Geological Society of America, Bulletin
- Additional Journal Information:
- Journal Volume: 129; Journal Issue: 5-6; Journal ID: ISSN 0016-7606
- Geological Society of America
- Research Org:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Org:
- National Aeronautic and Space Administration (NASA)
- Country of Publication:
- United States
- 58 GEOSCIENCES; GRACE; Nubian Sandstone Aquifer; aquifer; recharge
- OSTI Identifier: