Background

Groundwater is an essential part of the hydrologic cycle and a valuable natural resource. More than 1.5 billion people worldwide rely on groundwater for their primary source of drinking water. In many countries groundwater is also important for sustaining agriculture, industrial uses, streams, lakes, wetlands, and ecosystems. The use of groundwater has particular relevance to the availability of clean drinking water supplies. Groundwater may enhance the water supply because it has the capacity to help meet water needs during periods of increased demand, particularly during periods of drought and when surface-water resources are close to limits of sustainability.

Global groundwater resources may be threatened by human activity and the uncertain consequences of climate change. Recent research has documented the effects of direct human activity, such as groundwater mining and contamination, on groundwater resources. The effects of climate change on surface-water resources and associated ecosystems have also been evaluated; both those caused by human activity and natural variability. However, little is known about how subsurface waters in the vadose zone and groundwater might respond to climate change and affect the current availability and future sustainability of groundwater resources. Thus, there are urgent and ongoing needs to address the expected effects of human activity and climate change on global groundwater resources. To address these concerns, UNESCO-IHP initiated the GRAPHIC project in 2004. The project operates on a global scale in collaboration with regional, national, and international organizations and institutions in accordance with the GRAPHIC vision and mission.

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