EarthWorks Geospatial Catalog

Vernal Pools Study Area: Central Valley, California, 1998

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This polygon shapefile is believed to represent a boundary used for mapping vernal pool complexes in a study by Dr. Robert F. Holland (reference the mapped vernal pool complexes dataset named "usfwsvp2" for related information).True color aerial slides from the Deptartment of Water Resources were interpreted, and vernal pool complexes were identified. Complexes more than 40 acres in size were then digitized as polygons and given a density rating (see Resource Fields for attribute definitions). This layer was created to help biologists and resource planners make informed decisions in their recovery and planning efforts. It depicts vernal pool complexes, not individual vernal pools. Since the minimum mapping unit of the coverage is 40 acres, it may not provide the level of detail required for larger scale (smaller area, more site-specific) conservation planning.This coverage is a polygon layer of vernal pool complexes greater than 40 acres in size for 29 counties throughout the greater Central Valley, and some north bay counties. In 1995, Dr. Robert F. Holland identified the complexes on aerial photos (the most recent available for each county) and traced the polygons onto USGS 7.5' quads from which they were digitized. Vernal pool complexes were then given a density rating. The coverage was refined in June of 1998, with SPOT Imagery and recent U2 (low-flying aircraft) photography. The layer does not contain delineations of individual vernal pools and was not intended for use in wetland delineations. This coverage allows for display and analysis of existing vernal pool complexes in California's Central Valley.
California. Department of Fish and Game. Marine Resources Region
Central Valley (Calif.)
Vernal pools, Wetlands, Vernal pool ecology, Environment, and Biology and Ecology
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