Least-Cost - Wetlands

[WillFeltz]

Has anybody attempted to quantify wetland data and soil data for rate of resistance to estimate least-cost pathways? Many of studies I have seen put wetlands as high values, which I do not agree with for foot travel.

[PaulPrevedoros1]

Dear Will

The way I did it was to consider as time. I was working on Angkor Data, setup 1m grid and assumed a walking pace of 5km per hour which is equivalent to 0.8 sec/ metre. 

Thus when you do you walking you consider time to move a metre. 

Clue if you want to use 0.8 sec/ metre, multiple you costs by 10, then to get accumulated time divide time by 10

Works a treat.

Cheers

[PaulPrevedoros1]

Dear Will 

I have found an equation that may help even better this was one version of the algorithm

https://en.wikipedia.org/wiki/Tobler%27s_hiking_function

the formal paper

https://en.wikipedia.org/wiki/Tobler%27s_hiking_function

or

http://geographianapocensis.acad-cluj.ro/Revista/volume/nr_2_2012/pdf/Magyari_Dombay.pdf

these equations can enacted using the raster calculator

Works a treat

[PaulPrevedoros1]

I have done some thing like this in Angkor. Difference was that in rice paddies are difficult to walk on regardless of whether the paddy is wet or dry, Thus the bunds where the preferred surface.

I worked on the stating point of 5km. Check the work of Waldo Tobler

https://escholarship.org/uc/item/05r820mz

or 

DETERMINING MINIMUM HIKING TIME USING DEM

M.-S. Zsolt and D. ŞTefan

Geographia Napocensis 2012 Vol. VI Issue 2 Pages 124-129

and work from their logic.

I worked on the principle and experience people would avoid walking through wetlands especially is carrying stuff.

Cheers

paul prevedoros