DIGITAL SHORELINE ANALYSIS SYSTEM

Computer Software for Calculating Shoreline Change (and other problems dealing with the positional change of a boundary over time)

The Digital Shoreline Analysis System (DSAS) is computer software that computes rate-of-change statistics from multiple historic shoreline positions residing in a GIS. It is also useful for computing rates of change for just about any other boundary change problem that incorporates a clearly-identified feature position at discrete times.

The DSAS software is freely available.

CURRENT VERSION

The current version is 3.2 and is available here.

If you use it, please cite the following publication:

Thieler, E.R., Himmelstoss, E.A., Zichichi, J.L., and Miller, T.L., 2005, Digital Shoreline Analysis System (DSAS) version 3.0: An ArcGIS extension for calculating shoreline change: U.S. Geological Survey Open-File Report 2005-1304.

A public bulletin board for DSAS support is available to report bugs, as well as to exchange tips and techniques with the authors and other DSAS users.

https://woodshole.er.usgs.gov/cgi-bin/discus/show.cgi?2/2

CONVERSION UTILITY

DSAS transects created in the previous DSAS v.2x (for ArcView 3.x) can now be imported for use in DSAS v.3.0+ (for ArcGIS 9+) using the stand-alone utility available for download below.

http://woodshole.er.usgs.gov/project-pages/dsas/Transect_converter/DSAS_convert_transects.zip

Required inputs: - Multiple shoreline positions - User-generated baseline DSAS generates transects that are cast perpendicular to the baseline at a user-specified spacing alongshore. The transect/shoreline intersections along this baseline are then used to calculate the rate-of-change statistics.

Product/Results: - Transects added as new feature class in ArcMap - DBF text file of transect/shoreline intersections (x,y pairs) and distance to baseline - Statistics:      - End Point Rate      - Jackknife      - Least Squares Regression      - Weighted Least Squares Regression      - Supplemental statistics for Least and Weighted regression:             - Confidence Interval             - Standard Error             - R-squared

In this example, the DSAS was used to calculate rate-of-change statistics for a migrating bedform from sequential sidescan sonar surveys.  The Least Squares regression with 90% confidence interval graphically represents one of the many statistics reported by DSAS.

HISTORY

The DSAS software was originally developed in the early 1990’s and has undergone continuous, albeit episodic refinement. DSAS version 1.0 (1992) was written in the C and awk programming languages for use with the MapGrafix and ArcInfo Geographic Information Systems. DSAS 2.0 was written in Avenue for ArcView 3.x. The current version, DSAS 3.x, was written in VB.NET using the ArcObjects Object Library for ArcGIS 9.

Each version of DSAS includes many improvements that are described in the documentation. Typically, we concentrate our efforts on improving the rate-of-change statistics and the user interface.

PREVIOUS VERSIONS (unsupported)

The DSAS 2.0 is available at http://woodshole.er.usgs.gov/project-pages/dsas/version2 and should be cited as:

Thieler, E. R., Martin, D., and Ergul, A., 2003, The Digital Shoreline Analysis System, version 2.0: Shoreline change measurement software extension for ArcView: USGS U.S. Geological Survey Open-File Report 03-076.

The original DSAS version 1.0 is documented here http://pubs.er.usgs.gov/pubs/ofr/ofr92355 and should be cited as:

Danforth, W. W., and Thieler, E. R., 1992, Digital Shoreline Analysis System (DSAS) User's Guide, Version 1.0: U.S. Geological Survey Open-File Report 92-355, 42 p.

RELATED PUBLICATIONS

Thieler, E.R., and Danforth, W.W., 1994. Historical shoreline mapping (I): improving techniques and reducing positioning errors. Journal of Coastal Research, v. 10, no. 3, p. 549-563.

Thieler, E.R., and Danforth, W.W., 1994. Historical shoreline mapping (II): application of the Digital Shoreline Mapping and Analysis Systems (DSMS/DSAS) to shoreline change mapping in Puerto Rico. Journal of Coastal Research, v. 10, no. 3, p. 600-620.

These pages are provisional and contain computer software or scripts that may be changed without notice as new versions or revisions of the material are created. Although this program has been used by the USGS, no warranty, expressed or implied, is made by the USGS or the United States Government as to the accuracy and functioning of the program and related program material nor shall the fact of distribution constitute any such warranty, and no responsibility is assumed by the USGS in connection therewith.