4.3 Sustainability of Groundwater Resources

As world population continues to grow, so does the demand for irrigation and drinking water. The increased demand is frequently being met by the exploitation of groundwater resources, with groundwater pumping driving economic development in many areas of the developing world. Economic development, however, comes at an environmental cost, leading to declining water tables, reduced stream flows, the disappearance of wetlands, and salt water encroachment. The authors synthesize herein the latest research in the sustainable management of groundwater resources, with an emphasis on defining the sustainable yield of groundwater, estimating recharge, monitoring of groundwater depletion, and furthering the understanding of dominant controls on global variations in groundwater tables. The authors also discuss empirical and travel time-based approaches for predicting water-quality impacts of land-use change and conclude with a discussion of future research needs.