Description: <span style="font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif; font-size:16px;">Along North Core Banks, from Old Drum Inlet in the south to the Portsmouth Flats in the north, there were about 86 distinct </span><span style="font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif; font-size:16px;">outwash channels</span><span style="font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif; font-size:16px;"> that breached the dune during Hurricane Dorian. We examined these channels individually to determine their shape and volume. Sand loss was calculated from the SfM maps by subtracting the post-Dorian DEM from the pre-Dorian DEM to create a difference map. </span><span style="font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif; font-size:16px;">For each channel, the perimeter (P), area (A), length (L), width (W), and throat width (T) were measured in a GIS program. We also calculated the average depth (D</span><span style="font-size:0.70721em; font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif;"><span style="font-family:inherit;"> </span><span style="font-family:inherit;"><span style="font-family:inherit;"><span style="font-family:inherit;">avg</span></span></span><span style="font-family:inherit;"> </span></span><span style="font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif; font-size:16px;">) of the channels. Those depths, multiplied by the areas, were used to calculate the volume of sediment behind the dune lost by each channel during Hurricane Dorian. The maximum and average depths across the throat (D</span><span style="font-size:0.70721em; font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif;"><span style="font-family:inherit;"> </span><span style="font-family:inherit;"><span style="font-family:inherit;"><span style="font-family:inherit;">t-max</span></span></span><span style="font-family:inherit;"> </span></span><span style="font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif; font-size:16px;"> and D</span><span style="font-size:0.70721em; font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif;"><span style="font-family:inherit;"> </span><span style="font-family:inherit;"><span style="font-family:inherit;"><span style="font-family:inherit;">t-avg</span></span></span><span style="font-family:inherit;"> </span></span><span style="font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif; font-size:16px;">) were also extracted to estimate the velocity of the water flowing through the channel during the hurricane.</span>
Copyright Text: U.S. Geological Survey, Woods Hole Coastal and Marine Science Center