Water Resources Assessment Methods: Assessment of Groundwater Resources

Abstract

The fundamental challenge for managing groundwater resources in arid and semiarid lands is evaluating the response of aquifers to future short-term and long-term abstractions. This technical knowledge is then used as the basis for water-policy and management decisions. For example, groundwater pumping may be restricted to quantities that are considered sustainable, recognizing that sustainable or safe yields are, in practice, values that are difficult to quantify. Information is, therefore, needed on the impacts of various pumping rates and well distributions on aquifer water budgets, surface water resources, and sensitive environments. In the case of non-renewable groundwater resources, a strategy of planned depletion may be employed, in which case information is needed on the likely rate of future declines in aquifer water levels under different pumping scenarios and on various water resource replacement strategies (e.g., managed aquifer recharge) that may be required to meet future human and natural system requirements. Numerical groundwater modeling is a standard tool for making groundwater resource assessments and projections.