Évolution récente des conditions climatiques et des écoulements sur le bassin versant de la Macta (Nord-Ouest de l'Algérie)

In Algeria, the weather of the last three decades has a negative impact on water resources. The aim of this paper is to determine their impact on the rivers of the Macta basin (North-West of Algeria). The study of annual rainfall (September to August) over the period 1930-2002 shows a sharp decrease of rainfall from the first half of 1970. The flow of Trois Rivières station (wadi El Hammam), Sidi Ali Ben Youb station and Sidi Bel Abbes station (wadi Mekerra) were affected. Over the period 1976-2002, the annual average depth of runoff of runoff is 28 to 36% lower than for the period 1949-1976. On average, rainfall may be lower for all seasons, but the flows are not reduced in the autumn.