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This dataset represents the percent of non-agricultural, non-native vegetation based on LANDFIRE existing vegetation type (EVT) for a 30-m grid cell within individual local NHDPlusV2 catchments and upstream, contributing watersheds based on field reference data and Landsat, elevation, and ancillary data. EVTs are mapped using decision tree models, field data, Landsat imagery, elevation, and biophysical gradient data. Decision tree models are developed separately for each of the three lifeforms -tree, shrub, and herbaceous and are then used to generate lifeform specific EVT layers. The LF-GAP Map Units Descriptions provide descriptions for each LF EVT including species, distribution and classification information. Vegetation map units are primarily derived from NatureServe's Ecological Systems classification, alliances of the U.S. National Vegetation Classification (USNVC), and the National Land Cover Database and LF specific types. LANDFIRE EVT groups were reclassified into introduced managed vegetation cover where EVT_GP = (701,702,703,704,705,706,707,708,709,711,731). |
https://gaftp.epa.gov/EPADataCommons/ORD/NHDPlusLandscapeAttributes/StreamCat/HydroRegions/ |
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StreamCat currently contains over 600 metrics that include local catchment (Cat), watershed (Ws), and special metrics. The special metrics were derived through modeling or by combining other StreamCat metrics. These variables include predicted water temperature, predicted biological condition, and the indexes of catchment and watershed integrity. See Geospatial Framework and Terms below for definitions of catchment and watershed as used with the StreamCat Dataset.
These metrics are available for ~2.65 million stream segments and their associated catchments across the conterminous US. StreamCat metrics represent both natural (e.g., soils and geology) and anthropogenic (e.g, urban areas and agriculture) landscape information. |
https://www.epa.gov/national-aquatic-resource-surveys/streamcat-dataset |