GIS Analysis of Shoreline Change Using the Digital Shoreline Analysis System (DSAS)

Shelley Whitmeyer, James Madison University
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Initial Publication Date: June 7, 2017 | Reviewed: July 17, 2017

Summary

The Digital Shoreline Analysis System (DSAS) is a software extension for ArcGIS that allows for automated shoreline change calculations along the coast. The user must supply the shoreline data and the software helps the user create measurement locations (transects) and completes the shoreline change calculations at each location. The result is a visual representation of the shoreline change along a coastline. This representation is far more useful for analysis that one overall average. Unusually high rates of erosion/accretion are easily recognized from the resulting map.

The study location is Rodanthe, NC. The data used in this exercise is the sample data provided by the USGS.

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Context

Audience

This activity was developed for a GIS class of geology majors. The students are mostly juniors or seniors. The activity should take the students 2-3 hours. We began the activity in class and they finished it for homework.

Skills and concepts that students must have mastered

The students will...
  1. learn to add a new extension into ArcGIS,
  2. use the DSAS to calculate the shoreline change, and
  3. create a map showing a meaningful representation of the shoreline change.

How the activity is situated in the course

This activity was a case study presented to the students during the second half of the semester. At this point, the students had mastered the basic GIS concepts.

Goals

Content/concepts goals for this activity

1. Have the students complete a shoreline analysis in ArcGIS.

2. Teach the students how to install and use an external ArcGIS extension.

Higher order thinking skills goals for this activity

  1. Analyze shoreline data.
  2. Evaluate the results.
  3. Create a map displaying the results.

Other skills goals for this activity

Description and Teaching Materials

Student Handout (Microsoft Word 2007 (.docx) 3.4MB May31 17)

Thieler, E.R., Himmelstoss, E.A., Zichichi, J.L., and Ergul, Ayhan, Digital Shoreline Analysis System (DSAS) version 4.0—An ArcGIS extension for calculating shoreline change: U.S. Geological Survey Open-File Report 2008-1278. Data (Zip Archive 319kB May31 17)

Teaching Notes and Tips

The handout shows the students how to calculate the shoreline change using a linear regression. However, there are other statistical options such as end-point rate or net shoreline movement (see page 44 in the users manual). Once the students have completed the analysis as instructed in the handout, you could challenge them to find applications for the other statistics. For example, is your concern is the erosion caused by one storm the end-point rate might be more appropriate.

Assessment

The assessment is based on the map produced. The students should produce a map similar to the one below.


References and Resources

Data and extension from:

Thieler, E.R., Himmelstoss, E.A., Zichichi, J.L., and Ergul, Ayhan, Digital Shoreline Analysis System (DSAS) version 4.0—An ArcGIS extension for calculating shoreline change: U.S. Geological Survey Open-File Report 2008-1278.

DSAS User Guide and Download : https://woodshole.er.usgs.gov/project-pages/DSAS/version4/index.html

Note: Currently (May 2017) the DSAS does not work with ArcGIS 10.4. This should be fixed by the end of the summer. The tool does work with version 10.3 or earlier.