Adjoint Based Approach To Quantifying Stream Depletion Due To Aquifer Pumping Using A One-Dimensional Coupled Surface And Groundwater Model
Griebling, Scott A 1 ; Neupauer, Roseanna M 2
1 University of Colorado
2 University of Colorado
With growing populations and increased demand for water, it is necessary to ensure that increased pumping of aquifers does not reduce flows in rivers to levels that would limit the availability of water for drinking water supply, irrigation, and riparian habitat. Typically, analytical solutions and numerical simulations are used to quantify stream depletion, which is the change in stream flow due to groundwater pumping. These approaches require separate simulations for each potential well location and are inefficient tools for siting new well locations if the number of well locations is large. In this work, a coupled surface water and groundwater model is being developed to obtain stream depletion quantities due to pumping at any location in the aquifer. The model will couple the one-dimensional groundwater flow equation with the continuity equation for flow in a stream (Fig 1). The adjoint of this coupled system of equations (Fig 2) will be used to calculate, with one simulation, the stream depletion due to pumping at any location in the aquifer. The adjoint-based simulation will be run in MATLAB and can be used to identify feasible locations for new wells that limit stream depletion to acceptable levels.