Distribution, Morphometry, and Land Use of Delmarva Bays

Delmarva Bays are depressional wetlands that are elliptical in shape with sandy rims, and occur mainly in the central portion of the Delmarva Peninsula within the Mid-Atlantic United States. Situated in a region with abundant agriculture, Delmarva Bays and other wetlands may enhance water quality by reducing nutrient and sediment levels in local waters. A significant portion have been drained and converted from forested wetlands to agriculture. Using LiDAR to locate Bays, we estimate that there are 17,000 Bays on the Delmarva Peninsula, which is an order of magnitude greater than earlier estimates. Using a stratified sampling scheme based on Bay density, morphometric parameters of 1494 Bays were measured from the LiDAR data and their land use was assessed using aerial photography. Eighty percent of the Bays range in size from 0.46 to 5.68 ha, have a relief ranging between 0.55 and 2.02 m, and have a major to minor axis ratio between 1.08 and 1.65. Forty-one percent of the Bays sampled have been converted to agriculture and another 29 % have been partially converted, while 29 % retain natural vegetative cover. Improved understanding of the geomorphology, abundance and land cover of Delmarva Bays should lead to better management and conservation efforts.