1.9 Fossiles und neues Grundwasser als Teil des Gesamtwassers (Claus Kohfahl, Gudrun Massmann & Asaf Pekdeger)
1.9 Fossil and young groundwater as components of the hydrological cycle (Claus Kohfahl, Gudrun Massmann & Asaf Pekdeger)
Fossil and young groundwater as components of the hydrological cycle: First we define groundwater and aquifers, factors influencing groundwater quantity and quality and its relevancc ee aasr a resource. Groundwater is subsurface water which can be collected by wells, tunnels, or drainage galleries, or it can flow naturally to the earth’s surface via seeps or springs. It forms by infiltration of rain or surface water underground. Groundwater forms more than 30% of the global freshwater resources and is therefore a precious natural resource and of great importance for the drinking water supply. The abstraction of groundwater instead of surface water has a number of clear advantages. Groundwater is filtered naturally by physical and microbiological processes in subsurface layers during its recharge which generally results in a better water quality; nonetheless groundwater can be contaminated by geogene or anthropogenic factors. Depending on climate, morphology and geology the natural recharge varies between 2 and 50% of the annual precipitation. To guarantee sufficient freshwater supply for future generations sustainable management of groundwater resources in a quantitative and a qualitative sense is necessary. This requires monitoring strategies and research of water-rock interaction, which provide a means to control the quantity and quality of available groundwater resources in different hydrogeological contexts. Important strategies to enhance the formation of groundwater are artificial recharge via surface water bodies or wells, which are becoming more important in the future with regard to global climate changes.