Digital Shoreline Analysis System (DSAS)

Digital Shoreline Analysis System

Digital Shoreline Analysis System

DSAS software is used to calculate shoreline or boundary change over time. To download the free Add-in, click below:

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DSAS User Guide

DSAS User Guide

The newest DSAS v5.0 user guide provides detailed instructions for the implementation of DSAS.

Download User Guide

DSAS Tutorial Videos

DSAS Tutorial Videos

System Requirements and Installation reviews the requirements and instructions for installing DSAS.

Sample Data Workflow demonstrates use of the DSAS v5.0 software to produce rates of shoreline change.

Science Center Objects

Computer Software for Calculating Shoreline Change (or positional change of a boundary over time)

The Digital Shoreline Analysis System (DSAS) software is an add-in to Esri ArcGIS desktop v. 10.4-10.6 that enables a user to calculate rate-of-change statistics from multiple historical shoreline positions. It provides an automated method for establishing measurement locations, performs rate calculations, provides the statistical data necessary to assess the robustness of the rates, and includes a beta model of shoreline forecasting with the option to generate 10- and/or 20-year shoreline horizons and uncertainty bands.  A user-friendly interface guides the user through the major steps of shoreline change analysis. An in-depth user guide and video tutorials are available that provide detailed instruction on the DSAS workflow including: how to define a reference baseline for measurements, the steps needed to generate automated measurement transects and metadata based on user-specified parameters, guidelines on how to manually add or edit existing transects, and an explanation of the visualization options to display calculated rates of shoreline change and other statistical information.

DSAS

Current Version for ArcGIS 10.4- 10.6

DSAS version 5.0 was released in December 2018 and the Esri add-in is available for free here.  Click on "DSASAddin_v5.0.zip" to download the file. The supporting DSAS version 5.0 User Guide (found here) contains Installation procedures, system requirements, and detailed instructions for use.  For any questions regarding DSAS version 5.0 that you are unable to find answers to within the user guide, please contact DSAS_help@usgs.gov

What’s New in DSAS v5.0 

  • Advanced baseline placement options: Baselines located onshore, offshore, midshore (new!) or any combination of baseline orientations are now accepted.

  • Attribute Automator: a tool for easily adding required and optional attribute fields to shoreline and baseline data.

  • Rates returned as feature class: rate information is automatically spatially joined to DSAS transects for faster visualization.

  • Data visualization: rates of change are added to the map view with pre-set color ramps for rapid display and interpretation of results.

  • Beta shoreline forecasting: future shoreline horizons calculated with uncertainty bands for advanced interpretation of forecasted changes. 

  • Summary report: a text file is generated each time rate calculations are run capturing all DSAS settings, input data used for analysis, and a detailed summary of statistics including overall averages, maximum and minimum, as well as averaged erosion and accretion.

Introduction

DSAS generates transects that are cast perpendicular to the reference baseline to intersect shorelines at a user-specified spacing alongshore.  DSAS v5.0 supports a baseline located anywhere—offshore, onshore, in the middle of the shoreline data (midshore), or a combination of baseline placements. 

DSAS generated transect

DSAS generates transects that are cast perpendicular to the reference baseline at a user-specified spacing alongshore.  There are no restrictions on where the reference baseline is drawn, it may be positioned completely to one side of the shoreline data or be placed between the historical shoreline positions.  DSAS measures the distance between the baseline and each shoreline intersection along a transect, and combines date information, and positional uncertainty for each shoreline, to  generate the following change metrics:

(Public domain.)

Data visualization with scaled options applied

New to DSAS v5.0, data visualization allows the user to choose the way DSAS displays rate information. Options (shown above)  include (A) fixed scale and (B) scaled to data options. Examples of NSM (C) and SCE (D) are also displayed. The data itself has not changed – only the scaling and statistic selected through the DSAS “Data Visualization” tool.

 

History

DSAS has been a central component of the U.S. Geological Survey’s Coastal Change Hazards project, providing a robust suite of regression rates in a standardized and easily repeatable method that can be executed on large volumes of data collected at a national scale.  The DSAS software is intended to facilitate the shoreline change-calculation process and to provide rate-of-change information and the statistical data necessary to establish the reliability of the calculated results. The software is also suitable for any generic application that calculates positional change over time, such as assessing change of glacier limits in sequential aerial photos, river edge boundaries, or land-cover changes.  National and state governments worldwide have used the tool in support of resource management and critical coastal decision-making.

The DSAS software was originally developed in the early 1990’s and has undergone continuous 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 version 2.0 was written in Avenue for ArcView 3.x. DSAS version 3.x (ArcGIS 9), DSAS version 4.2 (ArcGIS 9) and DSAS version 4.3.4730 (ArcGIS 10) were written in VB.NET using the ArcObjects Object Library for ArcGIS. 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.

Utilities

Uninstall patch for DSAS version 4.x

This patch is ONLY for users who uninstalled ArcGIS 9.x before uninstalling DSAS version 4.x. Please note, when upgrading to a new version of ArcGIS, it is best to first uninstall custom ArcGIS extensions (such as DSAS). DSAS was developed using standard Esri-recommended methodology, but unfortunately cannot be removed if ArcGIS has already been uninstalled from the system. If ArcGIS 9.x was uninstalled (typical during a version update to ArcGIS 10) before uninstalling DSAS, the Esri libraries DSAS requires to unregister itself are no longer available. For users who find themselves unable to uninstall DSAS, use this patch.

Conversion utility for DSAS version 2.x

DSAS transects created in DSAS version 2.x (for ArcView 3.x) can now be imported for use in DSAS version 4 using the stand-alone utility available for download here