Farmland loss and retreat in the mid-Atlantic sea-level rise hotspot

Salinized farmlands consisting of dead crops and crop-free salt pans adjacent to salt marshes are a striking indicator of climate-driven sea-level rise. Here we quantify both the percent area change and vertical retreat rate of coastal farmlands between 1984 and 2022 along the US mid-Atlantic coast. The study region includes areas between 0-5 m above sea level with a special focus on the 0-2 m elevation - where saltwater intrusion is the most severe - across the Chesapeake Bay and the adjacent Delaware Bay. Particularly, the data package includes 2 shapefile datasets derived from four decades of Landsat satellite observations of coastal farmland dynamics. The two datasets are generated on the same spatial-scale and have the same spatial resolution of 0.075 km^2, both stored as hexagon grids with a side length of 170 m. Here we define "farmland retreat rate" (0-30 mm yr^-1) as the upward migration of the marsh-farmland boundary along coastal elevation averaged between 1984 and 2022, and the "farmland percent change" (0-100%) as the percent area change of arable farmland in each pixel from 1984 to 2022. All analyses are done on images after excluding man-made changes (e.g. farmland to forest conversion, farmland to urbanization).