DSAS 3.x Digital Shoreline Analysis System

1. DSAS 3.xDigital Shoreline Analysis System Rob Thieler1, Emily Himmelstoss1, Jessica Zichichi2, Tara Miller3 1USGS, Woods Hole 2Geonet Systems 3NOAA CSC

2. DSAS 3.xDigital Shoreline Analysis System • What is it? • A software extension to ESRI ArcGIS • Freely available • What does it do? • Calculates rate-of-change statistics from multiple shoreline positions • (and much, much more…) • Who uses it? • Scientists, engineers, managers, students, consultants… • In global use (30+ countries, 7 continents); ~500 downloads • Where can I get it? • http://woodshole.er.usgs.gov/project-pages/dsas/

3. DSASBrief History • DSAS 1.0 • Thieler and Danforth 1994, JCR • Unix-based (C, csh) • Not easy to use • Modified version used by MA CZM in late 1990s • DSAS 2.0 • Thieler et al. 2003, USGS OFR, on the web • Spurred by USGS National Assessment effort • ArcView 3.x (Avenue) • Easier to use… • DSAS 3.0 • Thieler et al. 2005, USGS OFR, on the web • ArcGIS 9 (VB.Net) • Better, stronger, faster….

4. DSASImplementation “Philosophy” • Use available ArcGIS (or other, e.g., 3rd party) functionality wherever possible • Employ standard editing and data manipulation tools • Exploit geodatabase and feature class structure • Concentrate on features not presently available elsewhere • Transect methods • Statistical output • Data organization and management

5. DSAS 3.xShoreline Change Analysis Software for ArcGIS 9 • Transects and other information added as new feature classes and output tables in ArcGIS • Output Statistics • End Point Rate (EPR) • Jackknife (JKR) • Least Squares Regression (LRR) • User-defined confidence interval, standard error, r^2 • Weighted Least Squares Regression (inverse-squared weighting) (WLR) • User-defined confidence interval, standard error, r^2 • Least Median of Squares (LMS) • Shoreline Change Envelope (SCE) • Net Shoreline Movement (NSM) • Functionality exists for including offset or “biased” shoreline positions • Package includes a user guide, tutorial, sample data, and on-line support forum

6. DSASData Requirements and Structure Fields are generated automatically when a new shapefile/feature class is created. Goal: embed information in the underlying data so that it travels with it and will largely comply with what you’re doing anyway (minimize extra work). Fields are generated automatically when a new shapefile/feature class is created.

7. Default Parameters

8. DSAS Default Parameters Pick one… 90, 95, 98, 99, 99.8, 99.9

9. Cast Transects

10. Transect spacing Baseline Shorelines Transect length Casting Schemes Two-legged (alongshore-averaged) Simple (locally perpendicular) 20m 20m

11. Transect intersections Transect Date, Accuracy Baseline

12. DSAS Output Tables

13. 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 Linear Regression, 90% CI

14. Shoreline Change Envelope, Net Shoreline Movement NSM SCE

15. Recalculate Transects

16. Recalculate Transects A lot of time is spent doing this… Pick a layer Some or all; clean up Overwrite or make new Pick a place (mostly for us to help solve bug issues)

18. About DSAS…

19. (XHWL – XMHW)offset Estimating the MHW - HWL Shoreline Bias After: Moore, Ruggiero, and List (in press, JCR) and Stockdon et al. (in press, Coastal Engineering)

20. For “biased” shorelines, the intersect is moved along the transect, then rates computed using the relocated intersect Date, Accuracy, Bias, Uncertainty

23. DSAS 3.x • A robust tool for rate-of-change estimation • It has to be, we’re doing the whole country with it… • Download at • http://woodshole.er.usgs.gov/project-pages/dsas/ • Package includes a user guide, tutorial, sample data, and on-line support forum • Take it for a spin!