Release of report, "The computer model SHARP, A quasi-three-dimensional finite-difference model to simulate freshwater and saltwater flow in layered coastal aquifer systems,"



In Reply Refer To:                           January 4, 1991
WGS-Mail Stop 411


OFFICE OF GROUND WATER TECHNICAL MEMORANDUM NO. 91.02

Subject:  PUBLICATIONS--Release of report, "The computer model
                        SHARP, A quasi-three-dimensional finite-
                        difference model to simulate freshwater
                        and saltwater flow in layered coastal
                        aquifer systems," by Hedeff I. Essaid

The attached report has been released as Water-Resources
Investigations Report 90-4130.  The report describes and documents
the computer model, SHARP, which simulates freshwater and
saltwater flow separated by a sharp interface in layered coastal
aquifer systems.  SHARP facilitates regional simulation of coastal
ground-water conditions in layered systems, and includes the
effects of saltwater dynamics on the freshwater flow system.  The
model accommodates multiple aquifers separated by confining
layers, with spatially variable porous media properties.  The
uppermost aquifer of the system may be confined, unconfined, or
semi-confined with an 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 report includes an overview of salt-
water intrusion modeling approaches and notes selected models that
have been developed for each of the approaches.

We recommend that this information be brought to the attention of
technical and management personnel concerned with ground-water
studies.

Copies of the computer program, SHARP, and additional copies of
this report are available from the author.



                                   Thomas E. Reilly
                                   Acting Chief,
                                   Office of Ground Water


Distribution:
  A, B, S, PO (Memo Only)
  FOLS (Memo w/attachment)