| Description |
This data release serves as an archive of coastal land-cover and feature datasets derived from Landsat satellite imagery at the northern Chandeleur Islands, Louisiana. To minimize effects of tidal water-level variations, only images that were collected within 2 hours of predicted low tide or that were collected on a rising tide with predicted water levels less than mean sea level at time of image acquisition were analyzed. Water, bare earth (sand), vegetated, and intertidal land-cover classes were mapped from Hewes Point to Palos Island using successive thresholding and masking of the modified normalized difference water index (mNDWI), the normalized difference bare land index (NBLI), and the normalized difference vegetation index (NDVI). Vector shoreline, sand, and vegetated feature extents were extracted for each image by contouring the spectral indices using the calculated threshold values. Barrier platform, beach, and vegetated widths were calculated from the intersection of the shoreline, sand, and vegetated vectors with transects spaced 300 meters (m) (10 pixels) apart alongshore. These data can be used to evaluate decadal-scale barrier landscape changes (Bernier and others, 2021). [More]
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