IMPETUS West Africa An Integrated Approach to the Efficient Management of Scarce Water Resources in West Africa — Case Studies for Selected River Catchments in Different Climatic Zones

Abstract

In the IMPETUS project thorough investigations of all aspects of the hydrological cycle are carried out within two river catchments in North West and West Africa: the wadi Draa in the south east of Morocco and the river Oueme in Benin. This choice is motivated by the possibility that the climates of Africa and Europe interact through atmospheric teleconnections, and the evidence that since the 1970s the droughts north and south of the Sahara have probably been related. Since the late 1970s Morocco has experienced a number of extremely dry winter seasons, the causes of which are not fully understood. They are assumed to be related to changes of the large scale circulation on interannual and interdecadal time scales as manifested in the North Atlantic Oscillation or the El Nino-Southern Oscillation. Against this background, the development of sustainable water resource management is a strong necessity. In this context the water-balance of the Draa catchment area and socio-economic implications are investigated. In order to address a number of imminent problems limiting the availability and allocation of water along the wadi Draa 12 measurement sites were installed along a gradient of elevation and aridity. Monitoring of the thickness and the extent of the snow cover in the High Atlas mountains is essential to enable the competing water users (power generation, irrigation, domestic consumption) to have adequate supplies. In addition to seeking a better understanding and prediction of the geospheric, atmospheric and biospheric components of the hydrological cycle, the IMPETUS activities centre around the questions of the influence, risks, and resulting conflicts of human activities in the context of the specific social and economical structures encountered in the area. A hierarchy of nested meteorological and hydrological models have been developed to assess the effects of environmental and anthropogenic change on the hydrological cycle and to analyse likely 'future scenarios'.