The Senegal River, a Disturbed Lifeline in the Sahel

Abstract

The Senegal River running through the arid and semi-arid parts of Senegal, Mauritania and Mali is of vital importance in this West African region. Multi-ethnic and multicultural populations have always been deeply dependent on its ecosystems and water for subsistence economies based on fishing, agriculture and livestock. Called the lifeline of the region, the Senegal River valley has experienced the earliest West African kingdoms as well as French colonization from 1624 onward, with the first French trading center at the river mouth remaining until independence in 1960. In hydrological terms, the Senegal River connects the humid upper parts of its valley with the drier basin area of its lower course, reflecting a strong climatological gradient that strongly affects biological and cultural diversity. After serious climatic changes, first apparent in 1968, that have devastated the entire valley, the riparian states of Mali, Mauritania, Senegal and later, Guinea, decided to join forces to master the availability of water and seek ways for rational and coordinated exploitation of natural resources. However, the river regulation infrastructure built (Manantali and Diama dams, dikes and other irrigation schemes) have had unforeseen environmental and socio-economical consequences along the Senegal River valley and the estuary. Among the impacts, salinization of soils, degradation of vegetation, the disappearance of native animal and plant species, diseases, the vanishing of some economic and socio-cultural activities and rural exodus, are the most important. Different protected areas have been created since the 1960s, all along the river, in part to reduce these negative impacts. However, the Senegal River currently remains a disturbed lifeline in the Sahel. Elements of the traditional cultural use of the river and respect for nature may contribute to the improvement of hydrological and hydro-agricultural schemes. Climate and hydrologySmaller tributary streams and rivers include Ferlo, Gorgol and Doué, as well as lake outflows of Lake Guiers in Senegal fed by the Ferlo River, and Lake R'Kiz in Mauritania. The Senegal River flows into the Atlantic Ocean south of the city of Saint-Louis. Each year, the river transports 22 billions m 3 of water past Bakel, considered to be the main reference station on the Senegal River due to its location below the confluence with the Faleme River, the last major tributary ( UNESCO-WWAP 2003).The atmospheric circulation in West Africa is determined by trade winds in the dry season and monsoon flows in the rainy season (fig. 5.2). All these atmospheric processes are governed by the Azores, Saint Helena high, the Saharan depression and the inter-tropical convergence zone. The monsoon winds are one of the necessary conditions for rainfall input (Nicholson 2013). However, the influence of oceanic and orographic factors are two elements to be considered in the evolution of temperatures, winds and precipitation.The average annual rainfall in the Senegal Basin is 550 mm, however there are large ...

River culture: How socio‐ecological linkages to the rhythm of the waters develop, how they are lost, and how they can be regained

“…River braiding had increased flood risk for the rural and urban population and destroyed harvests, and malaria was killing a considerable proportion of the colonisers of the flood plain so that the governmental project was broadly supported by the local population (Cioc, 2002). Damming the Senegal River protected the human population from floods and provided a huge gain in colonisable space, which was highly appreciated by the citizens of St Louis (Senegal), despite the fact that soil | 7 WANTZEN salinisation and the loss of fish and agricultural yields provoke severe problems in that area (Taïbi et al, 2022). In summary, the human perception of controlling floods was highly positive.…”

Water Quality Monitoring in the Volga Headwaters

“…The annual net transport from the sea to the land is 40,000 km 2 , and the river flow to the oceans also amounts to 40,000 km 2 per year [3]. Thus, among freshwater resources, rivers are often referred to as lifelines [4][5][6][7][8] or arteries [9][10][11][12], as lotic systems often formed the cradles of civilizations [13]. But we also need to take into account "flying rivers" [14] and that 40% of terrestrial precipitation originates from land evaporation [15].…”