Nubian Sandstone Aquifer System
| Country | Libya, Egypt, Chad, Sudan  |
|---|---|
| Coordinate location | 20°0′0″N 25°0′0″E |
De Nubian Sandstone Aquifer System (NSAS) be de world ein largest known fossil water aquifer system. E dey locate underground insyd de eastern end of de Sahara desert den dey span de political boundaries of four countries insyd northeastern Africa.[1]
De NSAS dey cover a land area wey dey spann just over two million km2, wey dey include northwestern Sudan, northeastern Chad, southeastern Libya, den most of Egypt. E dey contain an estimated 150,000 km3 of groundwater,[2] de significance of de NSAS as a potential water resource give future development programs insyd dese countries be immense. De Great Man-Made River (GMMR) project insyd Libya dey make use of de system, wey dey extract substantial amounts of water from dis aquifer, removing an estimated 2.4 km3 of fresh water for consumption den agriculture per year.
Characteristics
[edit | edit source]Since 2001, de Nubian Sandstone aquifer wey dey situate between de Toshka den Abu Simbel areas of Egypt undergo intensive drilling den development as part of a land reclamation project. Drilling information dem use to conduct a variety of studies wey dey regard de hydrogeological setting of de area ein aquifer.
Results dey indicate dat lithological characteristics den tectonic settings get a substantial effect on groundwater flow patterns den de area ein overall aquifer potentiality, wich be considered relatively low wen dem compare to neighboring areas insyd eastern Oweinat anaa Dakhla.
Geology
[edit | edit source]De aquifer be largely composed of hard ferruginous sandstone plus great shale den clay intercalation, wey get a thickness wey dey range between 140 den 230 meters. Groundwater type dey vary from fresh to slightly brackish (salinity dey range from 240 to 1300 ppm). De ion dominance ordering dey show dat sodium cation be most commonly predominating over calcium den magnesium – whereas chloride be predominant over sulfate den bicarbonate. De groundwater be of meteoric origin[3] (de term meteoric water dey refer to water wey dey originate as precipitation; most groundwater be meteoric insyd origin).
High concentrations of sodium, chloride, den sulfates reflect de leaching den dissolution processes of gypsiferous shales den clay, insyd addition to a lengthy duration of water residence.[4] Two recharge locations tie to specific epochs be identified by Reika Yokochj et al.: one 38,000 years ago wey dey originate from de Mediterranean, den de second dem date at around 361,000 years ago from de tropical Atlantic.[5]
International development projects
[edit | edit source]Since 2006, de international Atomic Energy Agency dey work insyd cooperation plus de four NSAS countries to help increase understanding of de aquifer ein complexities thru de IAEA-UNDP-GEF Nubian Project.[6] Project partners include de United Nations Development Programme (UNDP)/ Global Environment Facility (GEF), IAEA, United Nations Educational, Scientific den Cultural Organization (UNESCO) den government representatives from de NSAS countries. De project ein long-term goal be establishing rational den equitable management of de NSAS as a productive way of advancing socio-economic development insyd de region den protecting biodiversity den land resources.[7]
References
[edit | edit source]- ↑ International Atomic Energy Agency: NSAS Project Archived 2007-10-20 at the Wayback Machine
- ↑ Center for Environmental and Development for the Arab Region and Europe (CEDARE) 2000
- ↑ Samie, S. Abd El; M., Sadek (2001). "Groundwater recharge and flow in the Lower Cretaceous Nubian Sandstone aquifer in the Sinai Peninsula, using isotopic techniques and hydrochemistry". Hydrogeology Journal. 9 (4): 378–389. Bibcode:2001HydJ....9..378E. doi:10.1007/s100400100140. S2CID 129513948.
- ↑ A Study of Hydrogeological Conditions of the Nubian Sandstone Aguifer in the Area between Abu Simbel & Toschka, Western Desert, Egypt. American Geophysical Union, Spring 2001
- ↑ Yokochi, Reika; Ram, Roi; Zappala, Jake C.; Jiang, Wei; Adar, Eilon; Bernier, Ryan; Burg, Avihu; Dayan, Uri; Lu, Zheng-Tian; Mueller, Peter; Purtschert, Roland; Yechieli, Yoseph (13 August 2019). "Radiokrypton unveils dual moisture sources of a deep desert aquifer". Proceedings of the National Academy of Sciences. 116 (33): 16222–16227. doi:10.1073/pnas.1904260116. PMC 6697870.
- ↑ Brittain, John (June 22, 2015). "The International Atomic Energy Agency: Linking Nuclear Science and Diplomacy". Science and Diplomacy. Archived from the original on June 23, 2015. Retrieved June 22, 2015.
- ↑ "IAEA/UNDP/GEF Nubian Sandstone Aquifer System Medium Sized Project: Inception Meeting Report. November 9, 2006" (PDF). Archived from the original (PDF) on September 27, 2007. Retrieved September 20, 2007.
External links
[edit | edit source]
- Essay and Maps: Groundwater Resources of the Nubian Aquifer System
- Dahab, K.A., El Sayed, E.A. Study of Hydrogeological Conditions of the Nubian Sandstone Aguifer in the Area Between Abu Simbel & Toschka, Western Desert, Egypt. American Geophysical Union, Spring 2001