In any given 1-square meter point in this EnviroAtlas dataset, the value shown gives the percentage of impervious surface within 1 square kilometer centered over the given point. Water is shown as '-99999' in this dataset to distinguish it from land areas with low impervious. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas ) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets ).
EnviroAtlas - Durham, NC - Impervious Proximity Gradient