Optimizing the Rapid Evolution of Target Groundwater Potentiometric Surfaces

Abstract

ABSTRACT -THE long-term availability of adequate groundwater for sustainable irrigated agricultural production can be assured by causing the evolution and maintenance of an appropriate potentiometric (piezometric) surface in utilized aquifers. By providing adequate saturated thickness and hydraulic gradients and heads, such a surface affords some protection from the effects of drought, economic hardship, and environmental or legal complications. Procedures for determining desirable or optimal regional steady-state groundwater potentiometric surfaces have been reported by several researchers. An existing potentiometric surface can be forced to evolve into a desirable 'target' surface if it is subjected through time to the proper combination of recharges and discharges. Depending on the difference between initial and target surfaces, steady pumping strategies may require extended periods to complete the evolutionary process. The evolutionary period may be significantly shortened by using a time-varying pumping strategy. Such a strategy may be calculated by combining goal programming and simulation. The presented technique maximizes attainment of target potentiometric surface elevations within a predetermined planning period. It is a valuable tool for a management agency that is seeking to determine how to most rapidly achieve desirable groundwater conditions in either an undeveloped region or a region that has an existing pattern of groundwater pumping.