Hi Ulli,
If the trench is narrow (in terms of pixels), you can run a smoothing filter 
over that part of the DEM. Then replace the original trench pixels with those 
from the smoothed DEM using a conditional statement (gdal_calc with a ‘where’ 
statement).
Regards, Rick

________________________________
From: Qgis-user <[email protected]> on behalf of Ulrich 
Kriechbaum <[email protected]>
Sent: Thursday, November 8, 2018 5:49:12 AM
To: [email protected]
Subject: [Qgis-user] Manipulating DEM

Dear all!

I investigate a Glacial-Lake Outburst Flood and try to back-calculate the event 
using the simulation tool r.avaflow. During the event there was a big trench 
eroded. I have a post-event DEM with a clearly visible eroded trench. What i 
want to do now is to "flatten" out the trench so that i get a pre-event DEM to 
start my simulation. What i tried to do is to create the contour lines of the 
post-event DEM, change them so that they would not show the trench and then 
create a pre-event DEM out of this contour lines. I already asked the question, 
if anyone knows how to do that, i already got some nice answers but 
unfortunately none of the inputs really work for me....

So now to my actual question: Does anyone know another method how to "flatten" 
out the trench in the DEM? I would be really glad if someone would have an 
answer, as i have ben struggling a while now with these problem..

Best regards,

Ulli
_______________________________________________
Qgis-user mailing list
[email protected]
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Reply via email to