Computer Model SHARP, a Quasi-Three-Dimensional Finite-Difference Model toSimulate Freshwater and Saltwater Flow in Layered Coastal Aquifer Systems

摘要

The report documents the quasi-three-dimensional, finite-difference model, SHARP,which simulates freshwater and saltwater flow separated by a sharp interface in layered coastal aquifer systems. The model accommodates multiple aquifers separated by confining layers, with spatially variable porous media properties. The uppermost aquifer can be confined, unconfined or semi-confined with areally distributed recharge. Temporal variations in recharge and pumping are accounted for by multiple pumping periods. The boundary conditions which can be simulated in the model are: prescribed flux boundaries, constant freshwater head and/or constant saltwater head boundaries, and leaky head-dependent boundaries. The documentation includes an overview of saltwater intrusion modeling approaches and the mathematical formulation of SHARP. The model is verified against experimental and analytical solutions, and sample areal and cross-sectional applications are presented.