GGSD Program Details for SHARP

SHARP

Category	Groundwater flow (3D)
Publisher	US Geological Survey
Platform	DOS
Status	Public domain
Description	SHARP is a quasi-3D finite difference model for simulating freshwater and saltwater flow, separated by a sharp interface in layered coastal aquifers. The model accommodates multiple aquifers, separated by confining layers. The uppermost aquifer can be confined, semi-confined or unconfined with areally distributed recharge. Temporal variations in recharge and pumping are accounted for by introducing multiple pumping periods. The boundary conditions which can be modelled include prescribed flux boundaries, constant freshwater/and or saltwater head boundaries, mixed type boundary conditions. Aquifer properties can be both heterogeneous and anisotropic. The model can be used for both areal (horizontal) and cross-sectional (profile) studies. For each aquifer the vertically integrated freshwater and saltwater equations are solved. These two equations are coupled by the boundary condition at the interface. Leakage between the aquifers is calculated applying Darcy's law. The resulting system of non-linear partial differential equations is discretised using an implicit finite difference scheme. The discretised system of equations is solved using the strongly implicit procedure (SIP). The position of the interface tip and toe, within the discretised finite difference blocks, are tracked using linear extrapolation of the interface elevations calculated at grid points. Steady-state results are obtained by running a transient simulation until it achieves steady-state.
Cost	US Dollars 200
Data formats supported	None stated
Supplier in United States of America	International Ground Water Modeling Center
Supplier in United States of America	US Geological Survey