10 METER DIGITAL ELEVATION MODEL ================================== COVERAGE NAME: DEM10_ME1 FEATURE TYPE: RASTER -Arc/Info GRID format SOURCE: USGS DeciMeter Digital Elevation Models MINIMUM MAPPING UNIT: 10 meters (spatial resolution) AREAL EXTENT: Ten Mile, Noyo River, Big River, Albion River Hydrologic Units as defined by Calwater v2.2n DATE OF LAST UPDATE: 3/6/2000 INFO ITEMS: INPUT OUTPUT DATA DECI DESCRIPTION ITEM NAME WIDTH WIDTH TYPE MALS ---------- ----- ------ ---- ---- ------------------------------------ VALUE 4 10 B the elevation in meters (z=10) COUNT 4 10 B the number of cells with that value METHODS: 10 meter DEMs were merged together from Quads. Seamlines were then filtered out and sinks were filled. The Z Value is 10. These are decimeter precision DEMs, so to save space, the elevations were mulitplied by 10 to create an integer GRID that would preserve the precision of the data. CONTACT: Eric Spry, GIS Specialist CDF Fire and Resource Assessment Program 1920 20th Street, Sacramento, CA 95814 eric_spry@fire.ca.gov COORDINATE SYSTEM DESCRIPTION Projection UTM Units METERS Spheroid CLARKE1866 Parameters: 1st standard parallel 34 0 0.000 2nd standard parallel 40 30 0.000 central meridian -120 0 0.00 latitude of projection's origin 0 0 0.000 false easting (meters) 0.00000 false northing (meters) 0.00000 ADDITIONAL PROCESSING NOTES: Although the USGS DEM specification indicates that each posting is a floating point number, in most cases these have been rounded to the nearest integer. Therefore these lattices are stored as integers rather than floats, reducing storage requirements significantly. The DEMs were imported with the INT option. Because changing the projection of a grid requires resampling that can cause edge-matching problems, the DEMs have been left in their original projection, which is UTM zone 10 (west of longitude -120) or 11 (east of longitude -120). The best procedure for changing the projection is to merge adjacent grids first, then re-project. The most appropriate re-sampling methods are either bilinear interpolation or cubic convolution. Don't use the default nearest neighbor. DOCUMENTATION DATES: February 2002: Reprojected to UTM NAD27 (no shift), Z value reset to 1, and clipped to KRIS Project study area. Contact Name: P. J. Trichilo Institute for Fisheries Resources (IFR) 791 Eighth Street Arcata, CA 95521 Contact's Phone: (707) 822-9428