[en] Full text: In the framework of the BMBF (Federal Ministry of Education and Research) project 'Global change of the water cycle', IMPETUS West Africa focuses on water as a scarce resource. IMPETUS is an interdisciplinary and application-orientated approach from a research group of the universities Bonn and Cologne. As one of the investigation areas the Draa-Catchment in Morocco has been selected. Within the overall goal of IMPETUS: 'An integrated approach to the efficient management of scarce water resources' groundwater is of significant importance. In order to develop a conceptional hydrogeological model of the Draa-Catchment different scale approaches have been applied. Together with other disciplines investigations have been carried out in local test sites representative for geological and hydrological catchment areas and situated along a gradient of aridity and elevation. Based on natural labeling combined with classical hydrogeological and hydrological investigations for those testsites storage and discharge behavior of the various geological units have been defined. Besides local scale (IMPETUS test sites) regional scale approach was selected to understand the hydrogeological framework. The purpose of local scale investigation is to define the hydrogeological characteristics of each IMPETUS's test site commonly selected as a representative for the specific geological areas of the Draa catchment. In a further step this side specific information will be applied to a hydrogeological regional scale model. Basic requirements for a reliable hydrogeologic characterization are information on the geological structure as well as on the groundwater quantity/quality including hydrodynamics. Based on detailed geological mapping in the framework of master thesis geological and structural maps (1 : 25,000), geological profiles and lithological description are available for four testsites. Accompanied by chemical and environmental isotope measurements, carried out during base (autumn 2000, 2001) and high water flow conditions (spring 2001, 2002) the investigations allow a preliminary hydrogeological classification of the groundwater types in respect to their geogene mould, their seasonal variations and the origin of the water. More chemical and environmental isotope measurements are on the way to testify the classification. As an intermediary step in upscaling, hydrogeological investigations will focus on one important catchment area (sub regional scale). As a representative, the Asif n'Ait Ahmed catchment (60 km²) in the High Atlas is chosen. This catchment includes two test sites, already mapped. The geological mapping was accompanied by measurements of the groundwater quantity/quality, surface runoff and discharge of the receiving water course. Taking the size of the Upper Draa-catchment into account a different investigation strategy was chosen for the regional scale. The necessary geological and structural framework has been elucidated by both existing geological maps and geological evaluation of remote sensing data, added by selected ground checks. These information results in a first hydrogeological characterization. For a better understanding of the aquifer systems in respect to catchment area, age and groundwater recharge sampling campaigns have been carried out. Hydrogeological screening of the area between High Atlas - Basin of Ouarzazate - Anti-Atlas has been carried out in four profiles trending more or less N-S. The groundwater chemistry deviate considerably in both within and between the profiles. Observation points near the mountain rim hydrochemically exhibit a clear dependence on the nearby mountain geology. However, the hydrochemical pattern could not be used to solely determine the catchment area of the springs or wells. The environmental isotope measurements which have been performed show a reasonable correlation of δ²H/δ¹⁸O-data with the meteoric water. Deviations are partly due to enrichments by evaporation effects. Hence the regular sampling of rainwater in the new climatological stations started in autumn 2001, establishment of the local input function for the δ¹⁸O- and δ²H-content of the rainwater is still in progress. But first distinction of some catchment areas of the springs is possible. Currently performed tritium and carbon-14 sampling as well as the ongoing sampling for the stable isotopes will be used to validate those hypothesis. (author)