Abstract:
In karst basins where hydraulic structures ARE designed to utilize the existing water potential, de¬termination of the distinct groundwater flow patterns and the inter-relations among them bears great importance from the view point of the geotechnical safety of the structure. The combined use of hydrologic, hydrochemical and isotopic data enables us to identify different groundwater flow patterns prevailing in karst basins. Once the inter-relation among the groundwater flow patterns is established, the decision regarding the implementation of projects will be easier. Hydrologic investigations including analyses of the "stream yield" and "groundwater balance", produce invaluable in¬formation that can be used to locate the important karstic effluents along the basin. The study of the hydrochemistry of major karstic effluents reveals reliable information on the "depth" of underground circulation and the "recharge condi¬tions" dominating within the karst system. Evaluation of environmental isotopic data introduces important details pertai¬ning to the "mean recharge area elevations" and "turn-over times" of the karst waters and inter-relation among each other. Sometimes very closely located karstic outflows may have quite different circulation/recharge characteristics. This paper attempts to demonstrate the combined use of hydrologic, hydrochemical and isotopic techniques for the determination of the "deep-regional" and "shallow" groundwater circulation patterns existing in the Lower Zamanti Basin.