Transcript Cost Path Analysis of Skid Trails Using GIS Laura Heath December 14, 2006

Cost Path Analysis of Skid
Trails Using GIS
Laura Heath
December 14, 2006
FOR 557
Outline
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Purpose
Location
Analysis Approach and Obstacles
Results
Purpose
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Cost Distance Analysis
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Raster analysis that calculates the cost of traveling
from one cell to the next based on assumptions
specified by the user.
Goal:
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Determine least cost paths for skid trails in logging
operations.
Best Management Practices
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Limit the crossing of streams
No cutting within a 50 ft. buffer around streams and
bodies of water
Skid trail distances from water:
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50 ft with slope <10%
100 ft with slope >10% and <30%
150 ft with slope > 30%
Landings should be flat and well-drained
Use existing roads/trails as much as possible
Approach
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Obtain necessary information:
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Roads
Tax parcels
DEMs
Hydrography
Edit data to match with orthophotos
Vector
Data
Raster
Data
Vector
Data
Raster
Data
Vector
Data
Raster
Data
Cost
Surface
Cost
Distance
Cost
Path
Location
Sexsmith Lake in
Davenport, NY
®
Delaware
County
trails
roads
lake
river
harvest blocks
Step 1: Find location of landing
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Slope ≤ 3%
Within 100 meters of road
Intersecting the road
Not within 50 meters of a
body of water
Located within the harvest
stands
Step 2: Erase
Hydrography Buffers from
Harvest Stands
Step 3: Convert DEM to
Percent Slope Classes
blue: >30%
pink: 10-30%
purple: 5-10%
green: <5%
Step 4: Create Concentric Polygons Within
Harvested Stands
Step 4: Create Concentric Polygons Within
Harvested Stands
Step 5: Convert to Raster
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Spatial Analyst Toolbar → Convert → Features to Raster
 Slope (%)
 Concentric polygons (distance from edge)
 Roads (ID of 1)
Step 6: Reclassify
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Change values of cells to reflect cost of travel
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Concentric polygons:
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Slope:
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-300 → 1
-250 → 2
-200 → 3
-150 → 4
-100 → 5
-50 → 6
NoData → 7
0-5% → 1
5-10% → 2
10-30 → 5
>30% → 10
Road:
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ID 1 → 1
NoData → 50
Step 7: Overlay Rasters to Create the Cost
Surface
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GIS Help says to use
Weighted Overlay Tool
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I used the Raster Calculator in
Spatial Analyst
[concentric polygon] + [slope] + [roads]
Cost Surface
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Step 8: Create Cost Distance Raster
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The cost raster was created using the cost
distance tool
Cost Distance Raster
Step 9: Cost Path
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Calculates most efficient pathway given a destination, cost
distance raster and cost backlink raster.
Results
Questions?