PREDICTION IN HYDROGEOLOGY - 2 CASE-HISTORIES

An inherent aspect of hydrogeology is the dynamic character of groundw ater flow within the more passive lithospheric medium. Prediction ther efore requires insight into the spatial pattern of aquifer properties as well as the dynamic character of groundwater flow systems. Both asp ects together determine hydrogeological system behaviour in space and time. The spatial characteristics of an aquifer are mainly based on ge ological and geomorphological structure, whereas the dynamics of the s ystem result predominantly from climate and topography; knowledge of p aleoconditions are a prerequisite for sound understanding of present s ystems. The integration of exploration and forecast is illustrated by two case studies. The first study focuses on an assessment of groundwa ter resource and their sustainable development in semi-arid Botswana. The second study concerns the impact of land and water management in t he Netherlands coastal area on the groundwater regime and its future d evelopment, including the redistribution of salt and fresh groundwater on a long time scale.