Thank Nyall,
I will play with this tomorrow. I knew for the dissolve tool that is a bit
extreme as it basically make one single huge object (there goes the database!)
but not the split with line tool. I think I used multipart to single part to
achieve a similar result and had so far extract
On Sun, 14 Apr 2019 at 21:12, Nicolas Cadieux
wrote:
>
> Hi Micha,
>
> Great ideas, thanks. I was trying to get the v.drape to work in Qgis but I
> was getting errors. I figure it’s bad topology. I will fix it and try again
> directly in Grass.
Try using the native QGIS "drape" algorithm, no
On 14/04/2019 14:11, Nicolas Cadieux
wrote:
Hi Micha,
Great ideas, thanks. I was trying to get the
v.drape to work in Qgis but I was getting errors. I figure it’s
bad topology. I will fix it and try again directly i
How about iterating over the lines, read z from the raster for start and
end point and compare them?
No grass required.
On Sat, Apr 13, 2019, 22:31 Nicolas Cadieux
wrote:
> Hi,
>
> I have a difficult problem. I have a very large river network file made
> with a 2D shapefile. (I have the SRTM
Hi Micha,
Great ideas, thanks. I was trying to get the v.drape to work in Qgis but I was
getting errors. I figure it’s bad topology. I will fix it and try again
directly in Grass. I did manage to get the end nodes and start nodes. That has
not easy as the vectorizing was done in very small
Here's an idea, using GRASS, that might get you started.
First use the v.drape module to convert your river network to a
3D grass vector. Now add X,Y,Z coordinates to all start and end
points for all river sections with v.to.db. With that you can
extract t
Hi,
I have a difficult problem. I have a very large river network file made
with a 2D shapefile. (I have the SRTMs for the same region). I would
like to model a river network but I need to keep in mind the river flow
direction. Unfortunately, I think this file was manually digitized and
t
