St. Petersburg Coastal and Marine Science Center
By Rachel E. Henderson, Paul R. Nelson, Joseph W. Long, and Christopher G. Smith
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).
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://woodshole.er.usgs.gov/project-pages/DSAS/version4/.
|File Name and Description||Metadata (XML format)||Metadata (text format)||Download File|
Polyline shapefiles of Mean High Water (MHW) shorelines extracted from lidar elevation data from 1998–2014.
Polyline shapefiles of Wet Dry Line (WDL) shoreline delineated from historical aerial imagery from 1940–2015.
Polyline shapefiles of DSAS generated shore normal transects for the open-ocean shoreline of Dauphin Island, with associated rates of change for three shoreline analyses: Lidar shoreline change (1998–2014), Aerial shoreline change (1940–2015), and combined Lidar and Aerial shoreline change (1940–2015).
Polyline shapefiles of DSAS generated shore normal transects for the back-barrier shoreline of Dauphin Island, with associated rates of change for three shoreline analyses: Lidar shoreline change (1998–2014), Aerial shoreline change (1940–2015), and combined Lidar and Aerial shoreline change (1940–2015).
Open-ocean offshore baseline for generating shore-normal transects in DSAS.
Back-barrier offshore baseline for generating shore-normal transects in DSAS.
Henderson, R.E, Nelson, P. R., Long, J.W., and Smith, C., 2017, Vector Shorelines and Associated Shoreline Change Rates Derived from Lidar and Aerial Imagery for Dauphin Island, Alabama: 1940-2015: U.S. Geological Survey data release, https://doi.org/10.5066/F7T43RB5.