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<p>Hi everyone,<br>
</p>
<p>I have some doubts with the generation of a cost surface with <em>r.walk</em>
. It's assumed that the resulting layer is measured in seconds,
but when I try to convert seconds in days march (6h per day),
the resulting layer has no sense.</p>
<p>This is the workflow I'm following:</p>
<p><strong>1st.-</strong> I have several vector layers as roads,
rivers, bridges, and a raster layer of elevation.</p>
<p><strong>2nd.-</strong> Rasterize the vector layers with a field
named "weight" (PESO in spanish) where I have weighted this
variables according to if they facilitate the walking or not.
Reclassify is made if it's needed. </p>
<p><strong>3rd.-</strong> Find Slope (in percent) layer and
reclasify as follow: </p>
<ul>
<li>
<p>0-10=1; </p>
</li>
<li>
<p>11-maxValue=100</p>
</li>
</ul>
<p><strong>4th.-</strong> r.cross with all the rasterized layer.
(roads, bridge, river and reclassified slope).</p>
<p><strong>5th.-</strong> I create a new friction layer using this
formula proposed by Pandolf (1977) with <em>r.mapcalc</em> :</p>
<div align="center">
<pre><code>M=1.5W+2.0(W+L)(L/W)^2+"CrossedLayer"*(W+L)(1.5V^2+0.35V*abs("SlopeLayer"+10))
</code></pre>
</div>
<p><strong>6th.-</strong> With this layer measured in Watts I use
<em>r.walk</em> with default parameters. </p>
<p><strong>7th.-</strong> Once obtained this layer measured in
seconds I try to convert it in hours dividing 3600 and then
convert these hours in days march dividing 6 (6 hours per day).</p>
<p>Well, the results are not what I expected, the max data of this
layer is about 8.000... No sense, it should be something like 3
or 4 days, maybe. </p>
<p><strong><em>Here are <a
href="https://mega.co.nz/#%21UEh2kboY%21IHg20R2luT-_PyE_WG8ZJiDUu_lRWGlzSf8ynlWTN14"
rel="nofollow">the files</a> I'm using to do this
workflow.</em></strong></p>
<p>I don't know what I'm missing, maybe is the 4th step wrong?
Maybe the 5th? </p>
<p>Another point of view would be nice to me. If you need more
info, please ask for it and I will add to the question.<br>
</p>
<p>Thank you very much to everyone.<br>
</p>
<p>Thanks a lot!</p>
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