Upload
theodora-mcbride
View
213
Download
0
Tags:
Embed Size (px)
Citation preview
Concern
• Determine Concern
• 3 levels, based on number of viewers and area attributes.
• Route system usually provides the base.
Concern Level 1
• State and Federal Highways
• Wild/Scenic Rivers• Forest Highways,
Scenic Byways and major recreation sites & access
Build Level 1 points• Combine fishnet
with concern 1 routes using ‘Feature to Line’ tool.
• Delete Fishnet (concern = 0)
• Convert segments to points with ‘Feature to Point’ tool
Repeat for level 2• Combine fishnet
with concern 2 routes using ‘Feature to Line’ tool.
• Delete Fishnet (concern = 0)
• Convert segments to points with ‘Feature to Point’ tool
And again for level 3• Combine fishnet
with concern 2 routes using ‘Feature to Line’ tool.
• Delete Fishnet (concern = 0)
• Convert segments to points with ‘Feature to Point’ tool
Group for Processing• Subdivide
viewpoints into groups of 200-300 points.
• Use buffered clips of elevation, based on the zones.
Level 1 Viewsheds• Extract
Foreground Zone• Set up not seen
area mask for concern level
• Mask middle and background zones
FG1
MG1
MG1
BG1
BG1
Not seen
Level 2 Viewsheds• Extract
Foreground 2 Zone
• Set up not seen area mask for concern level
• Mask middle and background zones
FG2
MG2
MG2
BG2Not seen
Level 3 Viewsheds• Extract
Foreground 3 Zone
• Set up not seen area mask for concern level
• Mask middle and background zones
FG3
MG3
MG3
BG3
Not seen
Final Processing• Convert to
polygons• Classify grid
values and dissolve
• Eliminate zones less than 100 acres
• Clip to boundary
References• Landscape
Aesthetics- Agriculture Handbook 701
• ESRI Spatial Analyst Help Files
USFS-2010 David C. McMorran