Step By Step

1. Step By Step

2. Step 1Building Base Data

3. Concern • Determine Concern • 3 levels, based on number of viewers and area attributes. • Route system usually provides the base.

4. Concern Level 1 • State and Federal Highways • Wild/Scenic Rivers • Forest Highways, Scenic Byways and major recreation sites & access

5. Concern Level 2 • County Roads • Wilderness and wilderness access trails • Other scenic routes

6. Concern Level 3 • Other Forest Roads

7. Prepare Concern 12 miles • Buffer Project Area • Clip Concern Layer • Separate Concern by levels

8. Build Surface • Clip Elevation • Calculate roughness to use as impedance

9. Step 2Build View Zones

10. Distance Zones

11. Adding Topography

12. Cost Distance • Using the impedance raster compute the cost distance for each of the concern layers.

13. Concern level 1 • Calculate • Reclassify into zones BG1 FG1 MG1

14. Concern level 2 • Calculate • Reclassify into zones BG1 MG1 FG1

15. Concern level 3 • Calculate • Reclassify into zones FG1 MG1 BG1

16. Step 3Build View Points

17. Create Fishnet • Create 1 km Fishnet using XTools

18. 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

19. 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

20. 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

21. Group for Processing • Subdivide viewpoints into groups of 200-300 points. • Use buffered clips of elevation, based on the zones.

22. Viewsheds: Level 1 • Calculate viewsheds for each zone.

23. Viewsheds: Level 2 • Repeat modeling for Concern Level 2 points, by each zone

24. Viewsheds: Level 3 • And again, model viewsheds for the concern level 3 points, by zone.

25. Combine Viewsheds • Combine viewsheds for each concern level using MAXIMUM method

26. Step 4Combine view zones with viewsheds.

27. Masking Viewsheds • Use Viewshed to mask Zones • Unmask Foreground • Redraw Zones

28. Level 1 Viewsheds • Extract Foreground Zone • Set up not seen area mask for concern level • Mask middle and background zones Not seen BG1 MG1 BG1 FG1 MG1

29. Level 2 Viewsheds • Extract Foreground 2 Zone • Set up not seen area mask for concern level • Mask middle and background zones MG2 Not seen BG2 MG2 FG2

30. Level 3 Viewsheds • Extract Foreground 3 Zone • Set up not seen area mask for concern level • Mask middle and background zones Not seen MG3 FG3 BG3 MG3

31. Putting it together • Combine the resulting rasters

32. Final Processing • Convert to polygons • Classify grid values and dissolve • Eliminate zones less than 100 acres • Clip to boundary

33. A Closer Look

34. References • Landscape Aesthetics- Agriculture Handbook 701 • ESRI Spatial Analyst Help Files USFS-2010 David C. McMorran

35. Step By Step