5
votes
Accepted
Results from Strahler order/Stream rank (order) "cut" into squares - why?
These SRTM data use a geographic projection. Data with geographic projections result in these strange artifacts as described at Removing strange gdaldem hillshade artifacts. Reproject your surface ...
- 10.5k
3
votes
Accepted
QGIS: Saga Channel network: how to prepare SRTM data
You might want to try running Fill Sinks. This is available using SAGA via Processing. There may be GRASS versions too. I didn't see any mention of it in the tutorial you linked to, so it's worth a ...
- 20.6k
2
votes
Find the nearest point on a stream network from a given point?
You are looking for r.stream.snap tool, i think.
r.stream.snap - Snap point to modelled stream network.
Input can be stream network, point vector map with outlets or outlet coordinates.
It's a ...
- 7,888
2
votes
Accepted
New flow direction attribute for sub-catchment layer in QGIS
Even though you did not tag your question with GRASS, I would mention that the GRASS module r.stream.order captures into the streams attribute table the ID's for next_stream and the prev_stream for ...
- 15.8k
2
votes
Accepted
Why stream numbers generated by r.stream.order go one after other, not succeeding
The r.watershed has the added feature that it can produce "half basins" (each basin split in the middle by the enclosed drainage line). This is what causes even numbering of cat values for ...
- 15.8k
2
votes
Accepted
Obtain channel/stream network from a DEM in QGIS
Some recommendations for extracting drainage networks with SAGA. I guess the first thing you do is fill the dem with Wang&Liu.
In some cases the result depends on the minimum slope you define. ...
- 1,304
1
vote
How would I process and output every possible route of a stream network?
Not a real answer, but more than a comment..
TauDEM should be able to do what you want, and QGIS provides plugin support for it. There is an existing question here on GIS.SE that you might want to ...
- 6,486
1
vote
Simplifying stream network based on grid using QGIS?
You could use QGIS 3.0+ / Snap geometries to layer tool.
- 31.2k
1
vote
Validating that the smallest channel extracted using ArcMap (Hydrology toolbox) from DEM is the first-order stream
The definition you quote is one such definition. Another way of thinking about why you use Strahler order is to simply give your river some sort of context of where it is in the network. That network ...
- 44.6k
1
vote
Accepted
v.stream.order extension does not install in GRASS 8.2
According to the addon log file at
https://wingrass.fsv.cvut.cz/grass82/addons/grass-8.2.0/logs/
--> vector/v.stream.order FAILED log
There is a ctypes problem:
File "C:\msys64\usr\src\...
- 13k
1
vote
Stream order data for Canadian streams
In Ontario, at least, this data is maintained by each (most?) Conservation Authority, each of which is responsible for one major watershed. For instance, the Rideau Valley Conservation Authority has ...
- 8,416
1
vote
Obtain channel/stream network from a DEM in QGIS
Generally there are three main steps to creating a channel network.
Hydrologically controlled DEM
Catchment Areas
Channel Network
In more detail
Hydrologically controlled DEM
Use one of the Fill ...
- 5,519
1
vote
How to know stream order in QGIS on output of r.stream.extract
The GRASS GIS Addon v.stream.order computes the stream order of stream networks stored in a vector map at specific outlet vector points. It offers Strahler's stream order, Shreve's stream magnitude, ...
- 13k
1
vote
Accepted
Dissolve Lines without Dissolving Convergent Lines?
I have come up with an approach:
Create a point layer with points for each vertex in the stream network layer
Buffer each vertex a (small) desired amount (I arbitrarily chose 10 metres)
Run ...
- 105
1
vote
Flow direction without DEM / raster
I'm not sure of ways to do that without a DEM, however depending on the size of the project extent I would consider downloading a DEM from the SRTM site and running your analysis on that. The ...
- 153
1
vote
Making River/water map with stream order in QGIS?
I use routinely the grass-qgis extension and its ''hydrological modelling tool'' to create, accumulation and direction raster and river vectors .
have a look here: https://www.youtube.com/watch?v=...
- 11
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