Interactively Derive Streams and Catchments in QGIS Using the Graphical Modeller

[@BharatAmrutkalTrust]

Hes always imparting knowledge without keeping things to himself...so good a GURU G he is.

[@mandata143]

Hello Dr. I am from PH, a GIS practitioner. Thank you so much for giving us tutorials!

[@eric_eagle]

This is really cool. I use stream order as one input to a larger overland mobility model. I run it in a proprietary GIS right now but this makes me really interested to implement it in QGIS to compare performance. One thing QGIS lacked though the last time I tried, was Natural Breaks classification for Raster output.

[@HansvanderKwast]

Thanks. Natural Breaks is still not available in QGIS.

[@evanslion3548]

Thank you very much for this.

[@nbrahmareddy7690]

opentopography algorithm is not showing in the model designer in my QGIS as you shown at @2:42 . pls help

[@HansvanderKwast]

Try to create a new profile and install the plugin: kzbin.info/www/bejne/o3y3g3uCar5_oKssi=4Bl88tXCZ3uZ9Khl

[@Tylhuynh06]

This guy is a GOD

[@rkreddymrsv4958]

Good job sir

[@gisworld-tech]

great thanks for sharing

[@justinecarey9692]

Hi Hans, I have installed PCRaster using Conda on my MacOS (as per your other tutorial), however now when I try to run this model, I get an error that the grass7 r.thin algorithm is not available. When I check the plugins, GRASS GIS Processing Provider appears to be installed already, I'm not able to find grass7. Do you know a way to get both PCRaster and grass7 working successfully on a Mac? I have a series of approximately 50 sub-catchment areas I would like to calculate, so the tool you share in this tutorial would be really helpful. Thanks in advance.

[@HansvanderKwast]

Hi! GRASS doesn't work in conda (this is not specific to Mac), so you have to do that part in your regular QGIS installation on a Mac.

[@evanslion3548]

Thanks for the tutorial. I seem to have a problem installing the PC Raster Tools plugin. I get the following error "PCRaster Tools Plugin: PCRaster is not installed -- algorithms will not be available".

[@evanslion3548]

I am using the released version of QGIS 3.32.1

[@HansvanderKwast]

The PCRaster Tools plugin is a so-called Processing Provider plugin (like GRASS, SAGA, WhiteboxTools). Therefore, you need to install the software separately, before you can use the plugin. Here's the link to the documentation with installation instructions: jvdkwast.github.io/qgis-processing-pcraster/ More info about Processing Provider plugins in QGIS: kzbin.info9fWQZqPjPVk?feature=share

[@evanslion3548]

@@HansvanderKwast Very helpful. Thanks

[@robaitken4809]

Hans, as always your videos are truly amazing, thanks for taking the time to share! Is there an input or algorithm that could be used to select a DEM from a QGIS project or folder on your computer instead of from the Open Topography DEM Downloader?

[@HansvanderKwast]

Sure. When you edit the graphical model, just replace the OpenTopography part with a Raster layer input that links to warp. The rest is the same.

[@calvinquigley6000]

Hi Hans! This is really impressive. I tried to follow along, but when I run the model I get an error from GDAL's reproject(warp) "Attempt to create 0x0 dataset is illegal", which then causes convert_to_pcraster to fail with: src_ds = gdal.Open(input_raster.dataProvider().dataSourceUri()) AttributeError: 'NoneType' object has no attribute 'dataProvider' any idea what could be causing that? Thanks!

[@HansvanderKwast]

It looks like it didn't download the DEM. Check the results of the steps to see where it goes wrong.

[@armanocibaric9807]

Hi Calvin, I have been getting the same error. Have you managed to resolve it?

[@Zxxrys]

Thank you for this video , this will help my workflow faster. I have a question sir, there is this 'Error encountered while running Calculate flow Direction Execution failed after 14.97 seconds.'' How can i solve this one?

[@HansvanderKwast]

Probably you haven't installed the PCRaster Tools plugin correctly. It could also be that the area is too large or that it's not able to save the temporary file. Test the procedure manually, step by step in that case to see where the problem starts.

[@Zxxrys]

@@HansvanderKwast Thank you very much sir. Will surely do your suggestion!

[@NIXONGR123]

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