Groundwater, present almost every where beneath our feet, is by far (99%) the largest freshwater resource on earth. As rain falls, groundwater recharge and continuously feeds, rivers, lakes, wetlands and coastal waters. Through this process water solutes, pollutants and particles are continuously transferred from the surface, through the soil, into the deeper subsurface layers that ultimately discharge to surface waters or are abstracted from water supply and irrigation wells. Water migrates through sediment and rock pore spaces, rock fractures, faults in aquifers, and even underground caverns (karst aquifers) potentially polluting valuable groundwater resources and groundwater dependent or associated ecosystems.
In EGS, The Water Resources Expert Group focuses on the subsurface part of the water cycle i.e. water in the unsaturated (incl. soil) and saturated (groundwater) zone, and conjunctive use of groundwater and surface water.
Here are four examples of maps showing some of the topics:
- Estimated Potential Groundwater Recharge established in the TACTIC project.
- Volume (and depth) of European groundwater resources.
- DRASTIC vulnerability of European groundwater bodies to pollution from the surface.
- Geogenic arsenic and fluoride concentrations above drinking water standards in European aquifers.
Under GeoERA four water resources projects were conducted:
- TACTIC (Tools for Assessment of ClimaTe change ImpacT on groundwater and adaptation Strategies)
- HOVER (Hydrological processes and Geological settings over Europe controlling dissolved geogenic and anthropogenic elements in groundwater of relevance to human health and the status of dependent ecosystems)
- RESOURCE (Resources of groundwater harmonized at cross-border and pan- European scale)
- VoGERA (Vulnerability of Shallow Groundwater Resources to Deep Subsurface Energy-Related Activities)