**2.2 Slope**

A digital elevation model (DEM) from the United States Geological Survey National Elevation Dataset (USGS NED) was used to generate terrain slope at a spatial resolution of 10 m (http://viewer.nationalmap.gov/basic/?howTo=true) within ESRI ArcMap 10.5 (380 New York Street, Redlands, CA 92373-8100). The elevation values were collected with Interferometric Synthetic Aperture Radar, and referenced to the North American Vertical Datum of 1988 (NAVD 88). A preliminary analysis of the DEM was performed to fill in the low areas or "sinks" that are considered to be errors so that modeled runoff would flow smoothly across the land's surface. The filled output map was used to create the slope for the areas surrounding IRL. The percent slope was classified into three classes due to the low elevation throughout Florida.
