Caractérisation des effets du barrage de Manantali sur le régime hydrologique de fleuve Sénégal

Abstract

The effects of the Manantali Dam on the water regime of the Senegal River. Characteristic features. The hydrological regime of a river is a driving force of its ecosystem. The operation of dams and locks has significant impacts on the hydrological situation of rivers. Taking the example of the Senegal River, the hydrological section of upper basin was chosen to study the influence of the Manantali dam built on Bafing on hydrological regime. To do this, the daily flows measured at the Bakel hydrological station for the period 1951–2014 were used and divided into three series: a series of humid period (1961–1970); a series of dry period (1970–1988) before the impact of dam; a series on post-impact period (1988–2014). Based on the Indicators of Hydrologic Alteration (IHA), a range of variability of thirty-three hydrological parameters was calculated and the hydrological alteration associated with dam operation was quantified. Using the Range of Variability Approach (RVA), hydrological alteration at Bakel site was evaluated and showed the dam influence on hydrological state. The results showed a strong dam influence on hydrological regime; the eco-hydrological fluvial objectives calculated in the present study can constitute a certain support for water resources and ecosystems management of the Senegal River.

Key-words: water regime, indicators of hydrologic change, range of variability approach, Manantali dam, Senegal River basin.