A unit of Lasting Forests evolving since March 30, 1999
A Total Forest Management Plan and Wildland Management Decision Support System
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Treail Loaction Procedures

Using A GIS, follow the procedures of Blair Jones and Charlie Smart in locating corridors for high voltage power lines. This is a minimum cost pathway approach for finding the lowest cost between 2 points. You have to mark the origin and destination (e.g., a high point or a mid point on a circular path).

The computer moves off in all directions from the origin, evaluating the cost to move in any of the 3 directions from the last point. It saves the lowest total cost and moves again. The result os a pattern like root-hairs from a plant. The "costs" are artificial and include

1. higher cost of each move when closer to the destination (buffering GIS technique away from the origin)
2. lower costs on north facing slopes (beauty, cool, non-competitive with wood production or cultural practices)
3. lower costs (half that of southerly slopes)for high visibility cells (using GIS maps as developed by Jones and other)
4. lower costs for shale soils or geology (compared to sandstone which is harder to work)
5. lower costs the farther away from roads (tending to move the trail into more interior areas)
6. higher costs near noise sources
7. higher costs near streams (avoiding crossings, etc.)

Positive Approach

Recognizing that the shortest route will likely be the most cost effective, make a first-cut analysis and map.

Compute the mean slope between the origin and destination, A and B

Compute the difference between the mean slope and the slope in each GIS cell between the A and B, given the relative aspect and a positive contribution of getting from A to B, not exceding the maximum elevation, and not violating any excluded cells. Visually pick a pathway across the map to get the desired change in elevation, then deviate from it with switchbacks.

Compare the two approaches and devise others, recording the procedure after the trail is built to perpetuate improvements.

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This Web site is maintained by R. H. Giles, Jr.
Last revision October 17, 2002.