Vector Shorelines and Associated Shoreline Change Rates Derived from Lidar and Aerial Imagery for Dauphin Island, Alabama: 1940-2015

In support of studies and assessments of barrier island evolution in the Gulf of Mexico, rates of shoreline change for Dauphin Island, Alabama, were calculated using two different shoreline proxy datasets with a total temporal span of 75 years. Mean High Water line (MHW) shorelines were generated from 14 lidar datasets from 1998 to 2014, and Wet Dry Line (WDL) shorelines were digitized from ten sets of georeferenced aerial images from 1940 to 2015. Rates of change for the open-ocean (south-facing) and back-barrier (north-facing) coast were calculated for three groups of shorelines: MHW (lidar), WDL (aerial) and MHW and WDL shorelines combined. Calculations were performed using the Digital Shoreline Analysis System (DSAS) version 4.3, an ArcGIS extension developed by the U.S. Geological Survey (Thieler and others, 2009). For more information about the Digital Shoreline Analysis System (DSAS) see https://www.usgs.gov/centers/whcmsc/science/digital-shoreline-analysis-….

Thieler, E.R., Himmelstoss, E.A., Zichichi, J.L., and Ergul, Ayhan, 2009, Digital Shoreline Analysis System (DSAS) version 4.0-An ArcGIS extension for calculating shoreline change: U.S. Geological Survey Open-File Report 2008-1278, https://doi.org/10.3133/ofr20081278.