POD! GIS Shapefile of 50km buffer of the Upper San Francisco Estuary
This is an ESRI (ArcGIS) shapefile of a 50 km buffer surrounding the Upper San Francisco Estuary hydrodynamic subregions (see GIS Shapefile of Hydrodynamic Subregions of the Upper San Francisco Estuary data package). Contaminants can also be imported to the Estuary from upstream sources. As a rule-of-thumb, water travels approximately 50 km (30 miles) in a day. Therefore I delineated a drainage area that extends 50 km upstream from the boundary of the subregions (or until reaching the watershed divide where streams drain the western slope of the Coast Ranges directly into San Francisco Bay. This buffer area does not overlap with or include the hydrodynamic subregions.
The GIS Shapefile of Hydrodynamic Subregions of the Upper San Francisco Estuary layer was buffered to a distance of 50km (approximately one day's travel distance for water), (or until reaching the watershed divide where streams drain the western slope of the Coast Ranges directly into San Francisco Bay. The area of the Hydrodynamic Subregions was removed from this shapefile, leaving a "donut" polygon surrounding the subregions.
Data Set Usage Rights
This layer can be shared freely within the public scientific domain. It is intended to provide a general spatial framework for assessment of land use and other environmental effects on the Upper San Francisco estuary. It is not intended to be used for land use or regulatory decisions. The boundaries are only approximations made by buffering a shapefile derived from a small scale drawing.