HYDROGRAPHY ================================== COVERAGE NAME: STMGRAD - Stream gradient/Stream Order, v.1 FEATURE TYPE: LINE SOURCE: Appended 1:24,000 Scale USGS DLG Data Feb, 2000. MINIMUM MAPPING UNIT: 1:24,000 AREAL EXTENT: Hydrologic Units as defined by Calwater v2.2n DATE OF LAST UPDATE: 1/6/2002 COVERAGE DESCRIPTION: Large Water bodies and double-line streams were centerlined using the least cost path function in Arc/Info GRID to support hydrologic modelling functions. All Stream segments must be connected. They are then oriented to flow downstream, and desigated as to stream order, using the program stream_order.aml by David W. Lamphear, Forest Science Project. Stream names were conflated from EPA Reach File 3 1:100k data. Stream gradient was calculated using 10 meter USGS DEMs. Because of the use of DEMs rather than contour lines (hypsography) to calculate elevation, these data are subject to error, especially along mainstream channels where stream arcs may lie slightly off the channel as defined by the DEM. To produce stream gradient, the program uses Dynamic Segmentation to create an event table, that is used to sample stream segments at fixed interval STEPS: 1. Creates a route for each stream segment (ARCROUTE) 2. Creates an event table (ADDROUTEMEASURE) 3. Modifies table to sample at a fixed interval 4. Splits the route based on the new sample points (CALIBRATEROUTES) 5. Create new stream coverage (SECTIONARC) The program st_slope calculates stream slope base on node points in the stream layer. This program estimates slope based on the elevation values at FROM NODE and TO NODE locations. The following items are added to each arc: FELEV, TELEV, SLP Program requires: Stream coverage and DEM COORDINATE SYSTEM DESCRIPTION Projection Albers Units METERS Spheroid CLARKE 1866 Datum NAD27 Zone 10 central meridian -120 0 0.00 latitude of origin 0 0 0.000 longitute of origin 0 0 0.000 false easting (meters) 0.00000 false northing (meters) 0.00000 INFO ITEMS: INPUT OUTPUT DATA DECI DESCRIPTION ITEM NAME WIDTH WIDTH TYPE MALS ---------- ----- ------ ---- ---- ------------------------------ FNODE# 4 5 B - Arc/Info Standard Items TNODE# 4 5 B - Arc/Info Standard Items LPOLY# 4 5 B - Arc/Info Standard Items RPOLY# 4 5 B - Arc/Info Standard Items LENGTH 8 18 F 5 Arc/Info Standard Items STRMGRAD# 4 5 B - Arc/Info Standard Items STRMGRAD-ID 4 5 B - Arc/Info Standard Items F-MEAS 4 12 F 3 T-MEAS 4 12 F 3 KEY-ID 4 5 B - STREAMORDER 2 2 I - FLIP 1 1 I - FELEV 4 4 I - TELEV 4 4 I - SLP 8 8 F 2 DATA_SOURCE: DLG -Where source is DLG, 1:24k DLG quads were appended together F-MEAS : T-MEAS : KEY-ID : STREAMORDER : FLIP : FELEV : TELEV : SLP : CONTACT: Eric Spry, GIS Specialist CDF Fire and Resource Assessment Program 1920 20th Street, Sacramento, CA 95814 eric_spry@fire.ca.gov DOCUMENTATION DATES: DOCUMENTATION DATES: February 2002: Reprojected to UTM NAD27 (no shift), 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