Groundwater decision support linking causal narratives, numerical models, and combinatorial search techniques to determine available yield for an aquifer system /

by 1969- Pierce, Suzanne Alise

The calculation of sustainable yield for aquifers has been a controversial topic since its inception due to the difficulty associated with meeting the broad criteria used to define the term. As populations grow and demand for water increases, water managers need a way to calculate an acceptable extraction rate for a groundwater resource. This study looks at the difficulties associated with calculating a scientifically defensible aquifer yield and proposes an approach for quantifying an extraction rate based on both aquifer characteristics and societal concerns. A conceptual framework is outlined that can be used to consider the total available yield for an aquifer. With the identification of the range of available yields, the process further subdivides decision components into consensus and effective yield. Consensus yield is defined by the extent of community preferences acting as a bounded area within which operational strategies can be used to determine physically feasible extraction rates, or effective yield. Combining qualitative and quantitative methods provides an approach that can be generalized across different sites and easily adapted to a specific site. The final section of this chapter presents a preliminary identification of attributes within a hydrogeologic system that form the basis for simulating aquifer performance (effective yield) and linking that performance to specified stakeholder preferences (consensus yield). 1 Portions of this chapter were published in Pierce, S. P., Sharp, J. M. and Garcia-Fresca, B. (2004). " Increased groundwater recharge rates as a result of urbanization: Effects of urbanization on groundwater resources recharge rates, flow patterns, and sustainable development. " Hydrological Science and Technology 20: 119-127. 17