Positive Openness for North Carolina by HUC8

Rasters of positive openness for the 53 hydrologic unit code (HUC) 8 watersheds in the state of North Carolina. Positive openness uses a line-of-sight approach to measure the surrounding eight zenith angles viewed above the landscape surface out to a specified distance. The central cells gets and average of the eight angles. An angle of 90 degrees would indicate a flat surface, while angles less than 90 degrees indicate a concave surface. Positive openness was calculated with the Relief Visualization Toolbox (https://iaps.zrc-sazu.si/en/rvt#v, Kokalji et al., 2011; Zakšek et al., 2011) using light detection and ranging (lidar) derived digital elevation models (DEM) with a resolution of 10 ft. (~3m). A length scale of 60 ft.(6 pixels) was used to search surrounding terrain elevations in the eight cardinal directions.