Francis I. Chung

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This paper presents preliminary efforts by agencies managing California's water resources to incorporate climate change research into their planning and management tools. Projected increases in air temperature may lead to changes in the precipitation patterns, runoff timing and volume, sea level rise, and changes in the amount of irrigation water needed due(More)
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An open problem that arises when using modern iterative linear solvers, such as the preconditioned conjugate gradient method or Generalized Minimum RESidual (GMRES) method, is how to choose the residual tolerance in the linear solver to be consistent with the tolerance on the solution error. This problem is especially acute for integrated groundwater(More)
In the popular Newton-Krylov methods for solving large-scale systems of nonlinear equations, inner linear systems resulting from outer Newton linearization are solved by Krylov iterative linear solvers. The accuracy control of Krylov solvers are based on the progress of the Newton iteration to achieve good local convergence while avoiding over-solving. In(More)
In this paper, we describe the accuracy control and performance enhancement of linear solvers for the Integrated Water Flow Model (IWFM). This model is used by the State of California Department of Water Resources to assess the impact of climate change on water resources and the analysis of different conjunctive use scenarios across California. IWFM(More)
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