| Description |
This dataset represents a compilation of vector shorelines, shorepoints, and transects with rates for the Point Aux Chenes and Grand Bay estuaries in Mississippi and Alabama from 1848 to 2023. Shoreline data were obtained from multiple data sources, including the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the Grand Bay National Estuarine Research Reserve (GNDNERR), and the Mississippi Office of Geology (MOG). All shoreline data types have uncertainty associated with delineating the shoreline location, particularly with vegetated coastlines. For this study, the "apparent shoreline" was mapped for all data sources. The "apparent shoreline" is defined as "where the actual shoreline is obscured by marsh, mangrove, cypress, or other type of marine vegetation, the outer edge of the vegetation is mapped (Shalowitz, 1964). In the case of aerial imagery, vegetation-water boundary was digitized (Smith and others, 2021). Field surveys identified the edge of the dominant vegetation or the eroding scarp line (Smith and others, 2021). WorldView satellite imagery was classified using the normalized difference vegetation index (NDVI) (Maglione and others, 2014; Smith and others, 2021). Regardless of the source, all shorelines were merged into a single file to generate shorepoints and transects, in order to conduct shoreline change analyses. Datasets were compiled and analyzed using the R package Analyzing Moving Boundaries Using R (AMBUR) program (Jackson, 2010). This data release contains shorelines from 1848-2023 along with transects with rates of change joined to the data table, and shorepoints. Several shorelines were specifically digitized for use with transects in this study or have limited spatial resolution and are described in the attribute table or in this metadata record. This data release is an expansion of a previously published 1848-2017 shoreline change data release (Terrano and others, 2018). [More]
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