All Questions
663
questions
0
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1
answer
54
views
QGIS point sampling misses data on edge of raster (possible bug?)
It seems I may have discovered a shortcoming in the way QGIS handles raster sampling in points. Since yesterday evening (18/7), one small issue has begun to elude me (during my comeback geofictional ...
- 61
0
votes
1
answer
52
views
QGIS fill individual sink
I’m trying to determine the maximum extent of a pond when it is filled to its maximum capacity.
I think this is the same logic as the sink filling algorithms used for hydraulically correct dem’s - but ...
- 617
1
vote
0
answers
40
views
Brightness Differences in DEM TIFF File
I created a DEM file with QGIS. File type TIFF. The files I use as sources are also TIFF. The file, which looks normal in QGIS, looks different when I look at it in other programs. When I open the DEM ...
- 21
1
vote
0
answers
40
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Why does my raster look different after clipping it by a mask layer using QGIS?
I have a Digital Elevation Model of Europe and I want to clip it to the extent of Germany. To do so, I am using Clip Raster by Mask Layer with the external frontier of Germany as the mask layer. ...
- 65
-1
votes
1
answer
48
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I can't fill in the gaps in the DEM map [closed]
I downloaded the DEM files of the Balkan peninsula from the USGS website. I created a Balkan Peninsula DEM map larger than 3 GB from more than 130 DEM files, each of which is 25 MB. However, there is ...
- 21
1
vote
1
answer
435
views
130 TIF DEM file (total size 3 GB) become 7.4 GB TIF file after merging. Why?
I combined (Merge) 130 DEM maps via QGIS, taking up 3 GB in total. However, the total size of the combined file was 7.4 GB. I'm new to QGIS. It's only been a few weeks. I don't understand why the file ...
- 21
0
votes
0
answers
50
views
Combine DTM with hillshade in QGIS
I'm wondering if it is possible to combine a LiDAR generated DTM on a 1m Scale with a Hillshade DTM on a 0,25m Scale to improve the level of detail of the LiDAR DTM.
If possible how can this be done ...
0
votes
0
answers
53
views
Issue generating DEM with Natural Neighbour in QGIS 3.6 on different computers
I am trying to create a DEM using the Natural Neighbour algorithm in QGIS 3.6 Noosa. On my personal computer, I can successfully generate the DEM despite encountering a warning (shown in the attached ...
- 1
1
vote
1
answer
51
views
QGIS DEM to elevation Points, pixels not centred
I have a DEM which I'm trying to convert into a point layer in QGIS. I used the raster pixels to points tool, which seemed to work, except that the points are not in the centre of the DEM pixels. They ...
- 71
0
votes
1
answer
40
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QGIS: Set two raster to the same height
I have 2 DEM raster in QGIS. I want to merge them, but they have a difference in height of approx. 9m. This means that when I merge them, there is a kind of break-off edge at the transition. Can I ...
- 85
0
votes
0
answers
45
views
Calculating accurate viewsheds using DSM and DTM lidar data QGIS
I have a question regarding using DSM (Digital Surface Model) and DTM (Digital Terrain Model) data sets to create Zones of Theoretical Visibility.
I used the QGIS Visibility Analysis plugin to create ...
- 1
1
vote
0
answers
39
views
QGIS: Further subdivide sub-catchments based on DEM
I have a DEM and a vector layer with existing hydrological sub-catchments. Is there a way in QGIS to further subdivide the sub-catchments based on the DEM?
- 85
1
vote
0
answers
33
views
How to augment LiDAR/DSM data from 3d models
For a viewshed analysis in QGIS 3.34, the I have LiDAR/DSM geotif files available. I want to modify/augment the DMS layer by adding the height information from 3d models of specific buildings. This ...
0
votes
0
answers
14
views
Information in addition to Raster zonal statistics
I have a layer of polygons and a DSM. I want to know if I can extract average aspect, slope, and elevation statistics all at once in QGIS. I know another software does this but I forgot the name.
- 111
0
votes
1
answer
31
views
QGIS - transfer outcrop pixels from a DEM raster onto another raster surface at a lower level
In QGIS I would like a solution that will transfer pixels from a DEM raster onto another raster surface at a lower level. I am trying to create 2 geological surfaces, one being ground level (GL) and ...
- 49