Use of GRACE solutions for a better understanding of aquifer recharge sources, connectivity, groundwater flow, sustainability, and response to climate variability
Abstract
The extensive Saharan fossil aquifers of Africa (Nubian Sandstone Aquifer System [NSAS]; North Western Saharan Aquifer System [NWSAS]), and the Arabian Peninsula (Mega Aquifer System [MAS]) are essential fresh water resources for the sustenance of the local populations of Sudan, Libya, Chad, Egypt, Tunisia, Algeria, and Saudi Arabia. These fossil aquifers were largely recharged in previous wet climatic periods in the Pleistocene. Using GRACE mascon solutions of the Center for Space Research (CSR), we investigated the aquifer's recharge sources, connectivity, groundwater flow, sustainability, and their response to climatic variability. Findings indicate that one or more of the three fossil aquifers: (1) receive modern contributions from precipitation over recharge areas and from artificial lakes, (2) witness enhanced groundwater flow along preferred pathways (karst and fault networks) or impeded groundwater flow by basement uplifts that subdivide aquifers into subbasins, (3) experience rapid response to climate variability, and (4) could achieve sustainable extraction if the natural and anthropogenic discharge was balanced by recharge. The inferences from the analysis of GRACE solutions were corroborated by observations extracted from traditional data sources (remote sensing, geochemistry, structure, geophysics, and hydrology).
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H42C..05S
- Keywords:
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- 1836 Hydrological cycles and budgets;
- HYDROLOGY;
- 1847 Modeling;
- HYDROLOGY;
- 1855 Remote sensing;
- HYDROLOGY;
- 1873 Uncertainty assessment;
- HYDROLOGY