Hi,
I want to find a new route in an area of approx 50km*25km. The area is a remote and undisturbed with exposed land/glacier/water/forest/trees/wetland.
On the east side of the area there is a highway so I can use it as a start point, the end point is on the west side.
I have the contour so I generate a DEM-->Slope, I also downloaded the landcover of the area (LC Circa 2000).
I reclassify the landcover using the scale 1 - 10 (1 is the best) using my own interpretation:
1. Exposed Land
2. Herbs/Shurbs
3. Coniferous/Broad leaves/Mixedwood
4. Snow/Ice (it's okay to build on ice/glacier as the area is really remote and with lots of snow cover).
5. Water (it's okay with bridge construction)
6. Rock
10. Wetland (It's not possible to build on wetland).
NO DATA: Clouds, shadow.
I also reclassify the Slope data in a scale of 1-10 (1 is gentle, 10 is steepest). It is best to build the road on a slope between 0-30. With 30 degree or above will have a risk of avalanche. So at the end, scale of 1 to 3 is the best range....and then 4-10 will be too steep for a road.
So now I have 'Reclassed Landcover' and 'Reclassed Slope' and I run the 'Weighted Overlay' to create the 'Cost Surface'. I put equal influence on both variables.
With the 'Cost Surface' and the 'Site point' (where road ends/end point), I generate the 'Cost Distance'.
With the 'Start point' (Highway junction point I pick), 'Cost Distance', and 'Backlink', I generate the 'Cost Path'.
Discussions:
1. Do I have enough variables (I only have slope and landcover data). Should I use more data such as soil type? The area is pretty much covered with glacier/snow, trees, and some lakes/rivers.
2. The area is kind of hilly, with areas on glaciers are gentle in slope. It is also okay to cut some trees and to build the road on glacier. But I don't want to pick a valley where there are two steep slopes in between. So, do I need to use Curvature? How can I do that?
3. Any comments on how I should 'reclassify' the landcover and slope data? I use equal intervals (1-10).
4. I can't put too much criteria as ArcGis will not be able to find any route....but the bottom line is ok to build the road on glacier/across forests/water. Slope must be 30 degree or less and the road cannot be in a valley with steep slopes on the side.
Any "Spatial Analyst" experts can comment or give me some idea?
Thanks!
Winnie
