USGS - science for a changing world

Water Resources of the United States

SAC and SACGUI

Slope-Area Computation Program
SAC Graphical User Interface


The Slope-Area Computation (SAC) program follows USGS standardized procedures for computing discharge by the slope-area method. SACGUI is a stand-alone, runnable Java Archive (JAR) that interfaces with the SAC command-line Fortran program. SAC solves the 1-D steady-state energy and continuity equations for discharge given upstream and downstream water-surface elevations and hydraulic channel properties. The basic technique is presented in Measurement of Peak Discharge by the Slope-Area Method (Dalrymple and Benson, 1967). SACGUI provides a graphical wrapper around SAC to assist the user in developing the requried input files and viewing the results.

SAC requires (1) cross-section geometry and roughness values to describe the channel reach geometry and (2) measurements of high water marks. Results include discharges and other variables used in the computations.

Current Version: SAC - 2.0
SACGUI - 1.0.03
Release Date: August 27, 2013
Documentation: NOTE: Electronic and/or print versions of many U.S. Geological Survey reports can be found at the Publications Warehouse (http://water.usgs.gov/pubs/)
Bradley, D. Nathan, Slope-area computation program graphical user interface 1.0 - a preprocessing and postprocessing tool for estimating peak flood discharge using the slope-area method: U.S. Geological Survey Fact Sheet 2012-3112, 4 p. [PDF].
Fulford, J.M., 1994, User's guide to SAC, a computer program for computing discharge by the slope-area method: U.S. Geological Survey Open-File Report 94-360, 31 p. [PDF].
Dalrymple, Tate, and Benson, M.A., 1967, Measurement of peak discharge by the slope-area method: U.S. Geological Survey Techniques of Water-Resources Investigations, book 3, chap. A2, 12 p. ( http://pubs.usgs.gov/twri/twri3-a2/).
Version History ( release.txt )
Software User Rights Notice
Contact: U.S.Geological Survey
Office of Surface Water
415 National Center
Reston, VA 20192
h2osoft@usgs.gov

Distribution Files

Version

Operating System

Download File

Description

SACGUI 1.0.03
SAC 2.0

26Aug2013

Windows
Mac
README.txt Installation and usage information
InstallSAC-v1.0.03.jar
(26.6MB)
Installer program(Windows, Mac), includes executable program, sample data, and documentation

SAC 97-01

05May1997

Superseded

MS-DOS

README.TXT Installation and usage information
sac9701b.exe (449K) Includes executable program, test data, source code, and documentation
Sun Solaris README.TXT Installation and usage information
sac97.01.Solaris.tar.gz (307K) Compressed tar file, includes executable program, test data, source code, and documentation

USGS Home :: Biology :: Geology :: Geography :: Site Map

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://water.usgs.gov/software/SAC/
Page Contact Information: Office of Surface Water
Page Last Modified: Wednesday, 05-Mar-2014 08:37:20 EST