Most of the liquid freshwater resources are stored underground as groundwater (99%). The regional distribution on earth, however, varies and depends mainly on climatic conditions as well as the geology of the subsurface. In contrast to many raw materials, a great amount of the groundwater is recharged in the hydrologic cycle by infiltrating precipitation.
A detailed knowledge on groundwater resources enables its sustainable use, where the regional distribution of resources, the hydraulic characteristics of the aquifer as well as the regional and temporal variations of the water quality are important factors. The recharge, the natural runoff and groundwater abstraction rates have also to be known for sustainable groundwater management.
The data required for a resource assessment are obtained by hydrogeological exploration, observations and measurements at boreholes and wells, geophysical investigations on the earth’s surface, airborne geophysical surveys, satellite image analysis or meteorological observations. A number of geophysical standard methods such as geoelectrics, transient electromagnetics and airborne electromagnetics are applied for groundwater exploration. The surface nuclear magnetic resonance method and the seismo-electric method are rather new and they are still being developed. Databases combined with GIS methods are used to store and display the data. The data evaluation, being digital and increasingly three-dimensional, comprises all stages of conceptual to numerical modelling.
BGR operates in the framework of technical cooperation with developing countries or in the scope of federal tasks jointly executed with German geological surveys. BGR advises institutes in foreign countries and domestic institutes on the application of groundwater exploration methods, trains foreign partners and develops user-oriented methods. Furthermore, the effects of potential sea-water rises on coastal groundwater resources are investigated.
- D-AERO - German-wide Airborne Geophysical Mapping (German only)
- CLIWAT - Interreg IV Project Climate & Water (German only)
- Vietnam: Improvement of Groundwater Protection