Data Set Description:
This layer contains the boundaries of land and water for Alameda County, not including streams. E.g. Coastlines, reservoirs, islands, etc.
Non-standard Attributes in table:
- U_ID: Provides user with a unique identifier number for each polygon
- TYPE: Land or water.
- CLASS: Numeric assignment for TYPE (0: universe, 134: land, 234: water).
Data Source History:
The original dataset was a TIGER product. The water boundaries were isolated using a query on census feature class codes (CFCC) containing "H" (hydrologic features). The resultant layer was edited to contain only polygon outlines. This stripped the stream lines and left only ponds, lakes, reservoirs and the Bay. Finally, Jake Schweitzer, In Situ Mapping, redigitized the TIGER layer along the coast and inland lakes using Oakland's 1:100 scale, 1' pixel resolution orthophotos and a pre-existing marinas data set of boating docks.
Upon the adoption of the "streets" coverage and the digital orthophoto as Oakland's standard for coordinate accuracy, the hydro coverage was corrected using the arc/info "adjust" command with parameters based upon the node-to-node links established during the tiger-roads conflation process. This established a general-use hydro coverage. The second phase of conversion entails tracing the coastline and edges of waterbodies visible in the Digital Orthophoto. Jake Schweitzer, In Situ Consulting, updated the hydro coverage for both Oakland and its neighbors.
No security restrictions.
No scheduled updates.
Update process unknown at present