Water (Oct 2020)
Are the Fouta Djallon Highlands Still the Water Tower of West Africa?
- Luc Descroix,
- Bakary Faty,
- Sylvie Paméla Manga,
- Ange Bouramanding Diedhiou,
- Laurent A. Lambert,
- Safietou Soumaré,
- Julien Andrieu,
- Andrew Ogilvie,
- Ababacar Fall,
- Gil Mahé,
- Fatoumata Binta Sombily Diallo,
- Amirou Diallo,
- Kadiatou Diallo,
- Jean Albergel,
- Bachir Alkali Tanimoun,
- Ilia Amadou,
- Jean-Claude Bader,
- Aliou Barry,
- Ansoumana Bodian,
- Yves Boulvert,
- Nadine Braquet,
- Jean-Louis Couture,
- Honoré Dacosta,
- Gwenaelle Dejacquelot,
- Mahamadou Diakité,
- Kourahoye Diallo,
- Eugenia Gallese,
- Luc Ferry,
- Lamine Konaté,
- Bernadette Nka Nnomo,
- Jean-Claude Olivry,
- Didier Orange,
- Yaya Sakho,
- Saly Sambou,
- Jean-Pierre Vandervaere
Affiliations
- Luc Descroix
- Museum National d’Histoire Naturelle, UMR PALOC IRD/MNHN/Sorbonne Université, 75231 Paris, France
- Bakary Faty
- Direction de la Gestion et de la Planification des Ressources en Eau (DGPRE), Dakar 12500, Senegal
- Sylvie Paméla Manga
- LMI PATEO, UGB, St Louis 46024, Senegal
- Ange Bouramanding Diedhiou
- Master SPIBES/WABES Project (Centre d’Excellence sur les CC) Bingerville, Université Félix Houphouët Boigny, 582 Abidjan 22, Côte d’Ivoire
- Laurent A. Lambert
- Doha Institute for Graduate Studies, BP 200592 Doha, Qatar
- Safietou Soumaré
- LMI PATEO, UGB, St Louis 46024, Senegal
- Julien Andrieu
- Museum National d’Histoire Naturelle, UMR PALOC IRD/MNHN/Sorbonne Université, 75231 Paris, France
- Andrew Ogilvie
- UMR G-EAU, IRD (AgroParisTech, Cirad, INRAE, MontpellierSupAgro, University of Montpellier), Dakar 12500, Senegal
- Ababacar Fall
- Ecole Polytechnique de Thiès, Laboratoire des Sciences et Techniques de l’Eau et de l’Environnement, LaSTEE, Thiès BP A10, Senegal
- Gil Mahé
- IRD HSM, Case MSE, Université Montpellier, 300 avenue Emile Jeanbrau, 34090 Montpellier, France
- Fatoumata Binta Sombily Diallo
- CERE Centre d’Etudes et de Recherches sur l’Environnement, UGANC Conakry, Conakry 001, Guinea
- Amirou Diallo
- CERE Centre d’Etudes et de Recherches sur l’Environnement, UGANC Conakry, Conakry 001, Guinea
- Kadiatou Diallo
- Institut Universitaire des Hautes Etudes IUHEG, Conakry et GEOPROSPECT, Conakry 001, Guinea
- Jean Albergel
- Montpellier SupAgro, UMR LISAH, IRD, INRA, University of Montpellier, 34090 Montpellier, France
- Bachir Alkali Tanimoun
- NBA (ABN) Niger Basin Authority, Niamey 8000, Niger
- Ilia Amadou
- NBA (ABN) Niger Basin Authority, Niamey 8000, Niger
- Jean-Claude Bader
- UMR G-EAU, IRD (AgroParisTech, Cirad, INRAE, MontpellierSupAgro, Univ Montpellier), Univ Montpellier, 34196 Montpellier, France
- Aliou Barry
- Direction Nationale de l’Hydraulique, Conakry 001, Guinea
- Ansoumana Bodian
- Laboratoire Leïdi “Dynamique des Territoires et Développement”, Université Gaston Berger (UGB), BP 234-Saint Louis 46024, Senegal
- Yves Boulvert
- Senior Investigator of IRD
- Nadine Braquet
- UMR G-EAU, IRD (AgroParisTech, Cirad, INRAE, MontpellierSupAgro, Univ Montpellier), Conakry 001, Guinea
- Jean-Louis Couture
- Independent Consultant, 34980 Combaillaux, France
- Honoré Dacosta
- Département de Géographie, Faculté des Lettres et Sciences Humaines, Université Cheikh Anta Diop, Dakar 12500, Senegal
- Gwenaelle Dejacquelot
- Grdr Migrations, Citoyenneté, Développement, 93100 Montreuil, France
- Mahamadou Diakité
- OMVS Organisation Pour la Mise en Valeur du Bassin du Fleuve Sénégal, Dakar 12500, Senegal
- Kourahoye Diallo
- FPFD, Fédération des Paysans du Fouta Djallon BP 52 PITA, Timbi Madina 7311, Guinea
- Eugenia Gallese
- Grdr Migrations, Citoyenneté, Développement, 93100 Montreuil, France
- Luc Ferry
- UMR G-EAU, IRD (AgroParisTech, Cirad, INRAE, MontpellierSupAgro, Univ Montpellier), Conakry 001, Guinea
- Lamine Konaté
- OMVG Organisation pour la Mise en Valeur du Bassin du Fleuve Gambie, Dakar 12500, Senegal
- Bernadette Nka Nnomo
- Institut de Recherches Géologiques et Minières, Centre de Recherches Hydrologiques, Yaoundé BP 4110, Cameroon
- Jean-Claude Olivry
- Senior Investigator of IRD
- Didier Orange
- IRD, Cirad, INRAE, Montpellier SupAgro, UMR Eco&Sols, University of Montpellier, 34196 Montpellier, France
- Yaya Sakho
- SENASOL, Service National des Sols, Conakry 001, Guinea
- Saly Sambou
- Département de Géographie, Faculté des Lettres et Sciences Humaines, Université Cheikh Anta Diop, Dakar 12500, Senegal
- Jean-Pierre Vandervaere
- UMR IGE Univ Grenoble/Alpes, IRD, CNRS, Grenoble INP, Université Grenoble Alpes, 38058 Grenoble, France
- DOI
- https://doi.org/10.3390/w12112968
- Journal volume & issue
-
Vol. 12,
no. 11
p. 2968
Abstract
A large share of surface water resources in Sahelian countries originates from Guinea’s Fouta Djallon highlands, earning the area the name of “the water tower of West Africa”. This paper aims to investigate the recent dynamics of the Fouta Djallon’s hydrological functioning. The evolution of the runoff and depletion coefficients are analyzed as well as their correlations with the rainfall and vegetation cover. The latter is described at three different space scales and with different methods. Twenty-five years after the end of the 1968–1993 major drought, annual discharges continue to slowly increase, nearly reaching a long-term average, as natural reservoirs which emptied to sustain streamflows during the drought have been replenishing since the 1990s, explaining the slow increase in discharges. However, another important trend has been detected since the beginning of the drought, i.e., the increase in the depletion coefficient of most of the Fouta Djallon upper basins, as a consequence of the reduction in the soil water-holding capacity. After confirming the pertinence and significance of this increase and subsequent decrease in the depletion coefficient, this paper identifies the factors possibly linked with the basins’ storage capacity trends. The densely populated areas of the summit plateau are also shown to be the ones where vegetation cover is not threatened and where ecological intensification of rural activities is ancient.
Keywords
- Fouta Djallon
- water tower
- depletion (or recession) coefficient
- runoff coefficient
- soil water holding capacity
- basement