QGISHydro Webinar 4: Stream & Catchment Delineation

In this series of 7 free webinars during the Corona Crisis, Kurt Menke and Hans van der Kwast demonstrate the 7 chapters of the book QGIS for Hydrological Applications - Recipes for Catchment Hydrology and Water Management.

In this webinar we demonstrate how to perform stream and catchment delineation in QGIS using the SAGA tools from the toolbox. We also show how to visualise the flow direction map and use the 3D view.

(c) OpenStreetMap Contributors

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Note that with the new dependencies in QGIS this will not work.
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0:00 Introduction QGISHydro Webinar 4
7:59 Start demo Stream and Catchment Delineation
10:35 Download SRTM tiles
14:00 Mosaic SRTM tiles to virtual layer
15:38 Reproject and subset DEM
20:28 Fill sinks
22:28 Profile tool
23:33 Style DEM
26:18 Calculate Strahler orders
27:08 Style ordinal raster
28:08 Calibrate Strahler orders
31:50 Delineate streams and basins, flow direction
34:39 Style channels using calibrated Strahler orders
36:55 Style flow direction layer with ramp
42:30 Style flow direction using Crayfish plugin
46:22 Define outflow point
46:47 Delineate catchment
49:17 Polygonize the catchment
52:43 Clip layers to catchment boundary
56:20 Visualise in 3D view
57:48 Q & A
1:07:25 Shameless plugs

[chintanpurohit]

Thank you for this excellent video. For people like me who have no geographical training the whys of taking steps are very important and you explain it really well.

[antoniocesarcaetano]

Thanks a lot, Dr. Kwast, for these webinars videos. They are very helpful, with lots of tips and easy to follow. I've been learning a lot and I'm very grateful to you.

[giovanith]

Thank you very much for so valuable content, and yet for free. You make the difference for many people around the world.

[nnnnnnnn]

It is great to see the spirit of freely sharing information on the web still shining though! Thanks very much!

[nuclearant]

Great video! I have almost learned how to use QGIS from 0 to now on your channel. Thanks

[yengyangnaotou]

Thank you very much for your wonderful video Dr. Hans van der Kwast ! it help me a lot !

[WaqasSarwar]

Thank You sir for these very informative QGIS webinar series

[engopedia-bassimshama]

Great webinar delineation of catchments and streams
are the most important uses of Gis in hydrology

[olalekanolaiya]

Hello Hans, Thank you for this tutorial video. I would like to ask you how one can incorporate average sea level rise and RCP 4.5 scenarios into QGIS to model inundation levels

[ing.]

Thank you for this video. Knowing the hydrographic network, how I can determine the longest path from the point representing the section of closure of the basin?

[danianabri]

Thank you very much for this valuable webinar.

[damanminhas]

Thank you, this is quite nice. do we have a PDF version of the book as well on sale or its only hardcopy version?

[shubhamghungarde]

Hello sir, first of all thank you so much for your videos... Sir in my project Stahler order layer is not generating. I have checked all the file and folder names! Can you please help me in this?

[janaa]

hey, I''m a new user of QGIS. Its good actually.

[frankseawright]

Dec 7, 2022. I'm using Ubuntu 22 and qgis 3.22. I notice you use several SAGA MODULES, but I find that I cannot enable SAGA on this Qgis Version. Can it be done?

[rushianokun]

25:23 I think it did not work because it was set to "user defined", at least when I do it, the extent option gets greyed out. So the way It worked for me was Min/Max Value setting to Min / max and statistics extent to Updated canvas.

[aarizahmed]

It was a very nice and informative video. I have one query regarding spatial resolution since I am using cartosat-DEM having 10 m resolution so can I enter 10X10 while reproject the image.

[rakeshkumarchaudhary]

Thank you for your video. However I have some confusion regarding catchment area delineation, here I noticed that you have used Upslop for delineation up to outlet point rather than pour point In QGIS.

[florianlico]

Hello,
First, thank you for all the amazing webinars. They have helped me a lot
I am hitting a bump when trying to use the Upslope tool. I am sure the point falls on the 30 x 30 and I chose the filled DEM as the elevation. When I run the tool, I get the error: Tool needs graphical user interface.
Thank you in advance,

[BENAISSAHASSAN]

thank you so much
cheers from Morocco