International Symposium on
Drylands Ecology and Human Security
An Integrated Approach to the Efficient Management of Scarce Freshwater Resources in Northwest and West Africa: The IMPETUS-Project
Peter Speth, Michael Christoph and Andreas Fink
University of Cologne, Institute for Geophysics and Meteorology
Presenting Author: Prof. Dr. Peter Speth (Chair IMPETUS Project 2000 – July 2006)
In the IMPETUS project thorough investigations of all aspects of the hydrological cycle are carried out within two river catchments in West Africa: the Wadi Drâa in the south east of Morocco and the Ouémé river in Benin (IMPETUS: "An Integrated Approach to the Efficient Management of Scarce Water Resources in West Africa"). This choice is motivated by the indications found that since the 1970s the droughts north and south the Sahara have been related. In order to solve possible future problems with regard to fresh water supply, a clearly interdisciplinary approach is taken. The underlying method is demonstrated exemplarily on the basis of some pressing ‘problem clusters’. ‘Problem clusters’ are central issues, which can be analyzed and predicted only in a multidisciplinary approach. Adequate solutions for problem clusters are found and also implemented. The identification of problem clusters, the development of scenarios and the elaboration of solution strategies requires a close co-operation between local institutions and organizations, i.e. local stakeholders, and scientists. A problem cluster comprises a large number of individual thematic issues, each one reflecting a disciplinary process. Implementations of decision support tools for stakeholders are developed.
The talk concentrates on the arid regions in Northwest Africa.
Due to the importance of the hydrological cycle regarding the availability of fresh water, its different components and their interactions were identified in its complexity and quantified in the course of the first two three-year phase of this project. In an integrated approach a sequence of existing models (both numerical and expert models) of the individual disciplines involved have been adapted and validated in order to describe the relationships and dependencies within the hydrological cycle in its present state. Local conditions and problems of each catchment also had to be taken into account.
IMPETUS has set up three regional development scenarios until 2025 using expert knowledge and models from various disciplines. As an external climatic driving factor, the IPCC SRES scenario B2 has been used to force a nested atmospheric model hierarchy as a dynamical downscaling tool. In the present contribution the methodology of achieving such complex multidisciplinary scenarios will be presented and applications in the field of river hydrology and the influence of modeled land-use changes on rainfall will be presented.