Parallel numerical solution of groundwater flow problems.

摘要

Basin scale groundwater flow models are non-trivial because the domain typically covers several decades and thousands of square miles. The flow is governed by sh&d2;+1˙k h-b1h=Sh , which is highly nonlinear as a result of the h - b and S(h) terms.; This research investigates the use of parallel processing techniques to solve the groundwater flow equations. Reduced execution times allow more complex models to be used, generally resulting in the ability to better simulate features such as stream-aquifer interaction.; The BeoFLOW program was created by parallelizing the popular USGS MODFLOW program. File compatibility was retained to encourage adoption by the groundwater community.; BeoFLOW uses the linear (KSP) and nonlinear (SNES) parallel solvers in PETSc. One processor is dedicated to solving the surface water flow equations which cause complex, long-distance interactions. BeoFLOW also implements a new relaxation technique to prevent inadvertent occurrence of h - b 0.; The parallel techniques are evaluated using synthetic and practical problems, including the Rio Grande Decision Support System (RGDSS) Groundwater Model.