Jornal de Geologia e Geofísica
Acesso livre

Abstrato

Water Resources of African Circum-Sahara Sub Region (Renewable and Non-renewable Approach)

Al-Gamal SA and Younes Hamed

Circum is a preposition in Latin meaning “around” and Sahara is a preposition in Arabic meaning “Desert” so it is the regions around African desert. Studies related to Circum-Sahara are too little in-depth knowledge and focus on certain basins but, are generally limited by national boundaries, and do not take account of the transboundary portions of the reservoirs. The resulting development plans for these limited resources, thus, are seriously impeded by ignorance of the mutual effects of intensive withdrawal. Circum –Sahara region has the least renewable water resources of all geopolitical regions of the world, after the Middle East where the renewable fresh natural water resources amounts to 520 km3/year compared to 42,600 km3/yr worldwide. Surface water resources: These are represented by nine border crossing river basins of 1. Nile, 2. Niger 3. Senegal, 4. Gambia, 5. Volta, 6. Chari, 7. Guir-Saoura; 8. Mejerdah; 9. Juba-Shebelle. However and as a result of the arid or semi-arid climatic conditions which prevail in most of the region, the renewable surface water resources are not only temporally irregular but also often difficult to store. Groundwater resources: These are represented by eight border crossing aquifers and can be classified as renewable and non-renewable groundwater resources, these are 1- Nubian Aquifer System (NSAS); 2- North-Western Sahara Aquifer System (NWAS); 3-Senegalo-Mauritanian Aquifer System (SMAS); 4-Taoudeni Aquifer System (TAS); 5-Mourzouk-Djado Aquifer System (MDAS); 6-Irhazer-Iullemeden Aquifer System (IMAS); 7-Chad Aquifer System (CAS); 8- Errachidia Aquifer System (EAS). The yield of natural resources per inhabitant amounts to 1,000 m3/yr per inhabitant (which corresponds to a population density of 1,000 inhabitants per million m3/yr of resource) .At the present time, six countries of the Circum-Sahara region have natural water resources below 1,000 m3/yr per inhabitant (essentially the Maghreb, in addition to Egypt and Kenya). One of these, Libya, has less than 500 m3/yr. In 2025, another four more countries (Burkina Faso, Ethiopia, Morocco and Somalia) will have resources below 1,000 m3/yr per inhabitant, making a total of ten countries and 405 million inhabitants (69% of the total of all the Circum-Sahara countries).The future hydrology of this region is not rosy and may lead to political disputes.