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Optimizing Perennial Groundwater Yield Planning For Nonlinear Systems: Approach Comparison, Shu Takahashi, Richard C. Peralta
Optimizing Perennial Groundwater Yield Planning For Nonlinear Systems: Approach Comparison, Shu Takahashi, Richard C. Peralta
Civil and Environmental Engineering Faculty Publications
Four alternative simulation/optimization models useful for computing optimal sustained-yield (steady-state) groundwater pumping strategies are compared in terms of formulation, solution procedure, accuracy, and computational efficiency. The different models require different computer processing time and memory. For the aquifer tested system, if more than 10% of the cells have pumping as a decision variable, a fully linearized embedding model will require less computer memory than any other model. All the models address linear and nonlinear steady-state flow in multilayer, unconfined/confined aquifers. They also address several types of nonsmooth external flows. Newly presented are a response matrix model solving external flows described …
Optimal Linear/Nonlinear, Quantity/Quality Management Of Complex Multilayer Aquifers By Embedding, Ali Gharbi, Richard C. Peralta
Optimal Linear/Nonlinear, Quantity/Quality Management Of Complex Multilayer Aquifers By Embedding, Ali Gharbi, Richard C. Peralta
Civil and Environmental Engineering Faculty Publications
The embedding optimization modelling approach is adapted to aid long-term groundwater quality and quantity management of complex nonlinear multilayer aquifers. Implicit block-centered finite-difference approximations of the quasi-three-dimensional unsteady flow equation, and Galerkin finite-element approximations of the twodimensional advection-dispersion transport equation are embedded as constraints in the model. Other hydrological processes are also included as constraints. Cyclical linear differencing permits representation of nonlinear transport, even when contaminant is extracted by unsteady pumping (a decision variable). Also used are nonlinear (discontinuous derivative) constraints describing drainage, stream-aquifer interflow and evapotranspiration. The use of both linear and nonlinear formulations of the entire flow and …