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Major Groundwater Reservoirs of Egypt

2023; Springer International Publishing; Linguagem: Inglês

10.1007/978-3-030-95637-0_21

2522-8722

Mohamed H. Geriesh, Abdou Abouelmagd, Basma M. H. Mansour,

Groundwater flow and contamination studies

Egypt is known as the Nile’s gift because it relies on the Nile River for around 94% of its freshwater resources. As a result, Egypt’s national security is clearly dependent on the Nile River, where over a hundred million people are now concentrated in a narrow swath of the Nile Valley, which stretches from Aswan in the south to Cairo in the north. The Nile Valley and Delta are home to more than 97% of Egypt’s population. The Nile River supplies Egypt with 55.5 billion m3/year reflecting that the average available fresh water resources stand at 600 m3/year/capita in 2020 but considering population growth is expected to drop below the 500 m3/year/capita threshold of absolute water scarcity by 2030. The strategy of the Egyptian Government indicates that the agriculture sector holds 85%, industry 9.5%, and drinking 5.5%. Egypt anticipates a severe water shortage because of the Grand Ethiopian Renaissance Dam (GERD) building upstream of the Blue Nile. Great water demands due to increasing population rate and fixing water resource budget along with great water losses due to evaporation damming of water flow and supply are expected. Therefore, a promising strategic plan to develop water resources in Egypt that depends on developing traditional and non-traditional water resource supplies is recommended. Additionally, the deep groundwater beneath the vast deserts of the western, eastern, and Sinai Peninsula along with limited quantities of rainwater and flooding are considered non-renewable resources and can be exploited according to the development conditions and the water needs. Non-traditional water resources include the reuse of exhaust uses from agriculture, industry, sanitary, industrial sewage, and desalination. This chapter sheds the light on Egypt's major groundwater reservoirs as a potential and strategic solution for water shortage for expanding agricultural and economic activities until 2030. Egypt’s primary groundwater reservoirs are comprised of six aquifers, namely: (1) the aquifers of the Nile Valley and Delta, which are recognized as Egypt’s primary source of groundwater supplies and they both provide about 85% of all groundwater abstractions. Annual aquifer withdrawals are estimated at 6.1 Bm3/year, which is mostly replenished by excess irrigation water infiltration or through the irrigation network and Nile distributaries (2) The Nubian Sandstone Aquifer System (NSAS) is Africa’s largest fossil aquifer system, with estimated reserves of 150.000 Bm3. Around 2.2 million km2 of the NSAS are shared by Egypt, Libya, Sudan, and Chad, with Egypt contributing 828,000 km2 (38%). The thickness of the fresh water-bearing layer ranges from 200 meters in East Uwinat to 3,500 meters in the northwestern of El-Farafra Oasis. Between East Uweinat and El-Farafra Oasis, the fresh water layer’s thickness ranges from 200 to 3500 m. Recent studies have revealed that the NSAS receives transboundary recharge from Egypt’s, Sudan’s, and Chad’s southern and southwestern borders, as well as local recharge through major fractures and joints along its southern outcrops; (3) the Fissured Carbonate Rock Aquifer, which occupies more than half of Egypt's land area and stretches from the Sinai Peninsula to Libya. . It serves as a confining layer on top of the Nubian Sandstone Aquifer System and features numerous natural springs.; (4) the Fissured Basement Aquifer System, which is located in the Eastern Desert and the southern Sinai Peninsula and is often recharged by modern rainfall ; (5) the Moghra aquifer, which is located in the northwestern Desert of Egypt and the groundwater is flowing towards the Qattara Depression; (6) the Coastal Aquifers that are located along the coastal areas on the Mediterranean and Red seas. The groundwater abstractions are limited due to the risk of saltwater upconing . The groundwater reserve storage in these six aquifers has been estimated to be roughly 1200 Bm3 with variable recharge rates. The long-term sustainability of these aquifers depends on corrective actions including lowering the number of pumping wells, decreasing start-up and operating times, and setting up a drip irrigation system. It is strongly advised to monitor the quantity and quality of groundwater resources.