The first 8 attributes, MAJOR and MINOR codes 1-4, are part of the standard hierarchical coding scheme of the DLGs. The MAJOR attributes 1 and 2 are coded as 50 or 0, 50 representing a hydrographic feature digitized by the USGS, and 0 representing a hydrographic feature digitized by Wyoming Gap Analysis project.
The MINOR attributes 1,2,3 have a numeric code for each feature, for example 412 is the code for stream and 200 is the code for shoreline. Most features only have associated codes at the highest level, MINOR1. (MINOR 2 and 3 identify other codes; for instance a stream may also be labeled as intermittent in MINOR2 and labeled as a boundary for a wetland in MINOR3).
The most common MINOR2 attribute is 610, identifying intermittent features.
The last two attributes, ORDER and RIPARIAN, were added by Wyoming Gap. ORDER identifies the Strahler order for the stream, 1-7. Polygon labels do not have an ORDER attribute. Arcs identified as shorelines, wetland boundaries or terminal reservoir boundaries are labeled as ORDER = 0. A look-up table for displaying order in ArcPlot is included with the dataset, HYDRO.ORDER. The RIPARIAN attribute was added to identify intermittent streams which might possibly have riparian vegetation associated with them; this attribute was added only for the purposes of riparian modeling in Gap Analysis and has no other functional use within the dataset.
Definitions of Minor1,2 and 3 codes are listed here and are also included in two INFO tables accompanying the Arc/Info coverage: HYDRO.LINE and HYDRO.POLY. These files can also serve as display look-up tables for Arcplot, since they include symbol colors for the COLOR lineset.
For ArcView users, these INFO files are also available as dBASE files, hy_line.dbf, hy_poly.dbf and hy_order.dbf.
Definitions for line attribute values (.AAT):
200=Shoreline 412=stream 605=right bank 606=left bank 420=wash 103=glacier boundary 201=man-made shore 406=dam or weir 202=closure line 203=indefinite shore (identifies high-water mark) 204=apparent limit 400=rapids 401=falls 610=intermittent (all else assumed perennial)Definitions for polygon attribute values (.PAT):
101=reservoir 103=glacier 105=inundation area 108=submerged area (due to dam-building) 109=sewage pond 110=tailings pond 111=marsh/wetland, 402=gravel pit 412=wide river (represented by left and right bank) 420=emphemeral wash 421=lake or pond.