Groundwater

Groundwater represents 98% of the world's unfrozen freshwater and its use has increased significantly over the past 50 years due to its high reliability during drought seasons, good quality and generally modest development costs.

We know more about groundwater and aquifers from work completed during previous Intergovernmental Hydrological Programme (IHP) phases, but we need to learn more about the complexity of aquifer systems, the increasing global risk to groundwater depletion, quality deterioration and pollution, and the resilience of communities and populations dependent on groundwater sources.