Vegetation - Great Valley Ecoregion [ds2632]

Geodatabase feature class containing a map of vegetation within the Great Valley Ecoregion produced by the Geographical Information Center (GIC) at CSU Chico. The dataset combines both new mapping and the previously completed Central Valley Riparian and Sacramento Valley and the Southern San Joaquin Valley vegetation maps. Vegetation polygons were manually digitized as interpreted using the National Agricultural Inventory Programs (NAIP) 2009 (Central Valley Riparian and Sacramento Valley map), 2012 (Southern San Joaquin Valley map) and 2014 (balance of San Joaquin Valley) aerial imagery at a scale of 1:2000. The minimum mapping unit (mmu) for natural vegetation is 1.0 acre, with a minimum average width of 10 meters. The mmu for agricultural and urban polygons is 10 acres. Vegetation is attributed to the Group and Alliance level of the state and national vegetation hierarchy. In some cases, polygons were attributed only to Group or Macrogroup level when the Alliance could not be determined from photointerpretation. The map classification is based on the key to vegetation types in Buck-Diaz et al. 2012. The Central Valley and Sacramento Valley maps were assessed for Accuracy with an average users accuracy of 90.2% and users accuracy of 89%. The San Joaquin Valley portion of the map was field verified by the mappers but was not otherwise assessed for accuracy (see Supplemental Information below for details).