Abstract: Streamline is a linear coverage of the hydrography of the Walnut Gulch Watershed. Streamline was derived from the coverage 'streams'. Streams was hand drawn from 1:5000 aerial photographs. Streamlines was created from the perpendicular bisector of the channel polygons in the streams coverage.

Procedure: Source of streamline was the polygon/linear coverage 'streams'. The coverage streams was created by hand drawing channel features onto mylar sheets off of 1:5000 aerial photos (ortho-rectifited). Polygons and lines were then subsequently digitized and attributed. The streamline coverage is the linear representation of the stream network within the Walnut Gulch Watershed by creating the perpendicular bisector lines from the polygonal channel features. The coverage streams was created with the projection and coordinate system of UTM 12N, NAD27, and Clarke1866. This coverage was updated to UTM 12N, NAD83, and GRS1980 in February 2004. Projectdefine command in ArcINFO used to establish original projection in coverage. Project command in ArcINFO used to change datum.