Stream and catchment delineation with GIS (theory)

This video show how to derive streams and catchments from a DEM using geographic information systems (GIS). The whole workflow will be presented, which includes, DEM aquisition, mosaic, reprojection, void filling, filling of sinks, Strahler order, D8 flow direction and much more.
This video is part of IHE Delft OpenCourseWare. More free resources can be found at www.gisopencourseware.org
For an overview of our GIS courses and info on tailor made trainings and advise see our folder: www.un-ihe.org/sites/default/...
More information about the book "QGIS for Hydrological Applications - Recipes for Catchment Hydrology and Water Management" by Kurt Menke and Hans van der Kwast can be found at the website of Locate Press: www.locatepress.com/hyd
IHE Delft and Nieuwland Geoinformatie offer an online course. It includes support from experienced trainers and you'll get the official QGIS certificate after completion. More info at: www.learning-gis.com
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[@winkdong]

Been attracted to the Contour line + Catchment representation, and didn’t expect such a informative explanation!

[@masoodrasoli4469]

A great video for learning the basics.

[@gezahagnnegash9740]

Thanks a lot for your nice explanation and presentation

[@thangamaninmamit-civil6860]

Excellent explanation. Thank you somuch

[@dayansaynespuma6812]

Muchas gracias por la explicación. Muy didáctico.

[@YoussefHarby]

This is perfect , thank you !

[@sabinjoshi007]

Thank you for the informative video..

[@agilariefrachman6239]

Thank you very much sir

[@surjithpm]

You are amazing.

[@athlete265]

excellent explantion

[@AbdullahSalimalig]

u r amazing sir

[@akindipeoluwadamilare591]

Thank you for this, it was clear and concise.

[@cilbup]

very helpful

[@farzanesadeghi2908]

thanks a lot

[@angelos.1972]

Great video. Thanks for sharing! You said that it does not work for flat area and human controlled environments, do you have a workflow for such a case? Thanks A.

[@HansvanderKwast]

In human controlled environments you have to look for maps from the authorities who manage the water. If that's not available you can do a visual interpretation. Unfortunately there's no algorithm yet that can interpret the human control on the environment and translate that into a catchment map. For flat areas that are not human controlled, you can play with the minimum slope parameter in the fill sinks algorithm or burn in the river network if you have a hydrography layer. In that way you force the water to follow the existing river system. No videos about this yet.

[@angelos.1972]

By human controlled environment I actually ment artificial ditches networks in flat area that make difficult to get a reliable catchment area, so I guest that by burn on the ditches network on the dem and playing with fill sink minimun slope would help a lot. It you believe is relevant for the channel would be great to have a video...otherwise thank you again for tour much appreciate help! A.

[@gemmam9892]

Hi Hans! In the 'fill sinks' step, you say real sinks (e.g. lakes) need to be added after pit removal. How can this be done? I have polygon layer of lakes if that is of use?

[@HansvanderKwast]

You can burn those in the DEM to force that the DEM is lower at those locations. Similar as burning rivers. We made some tools that are available in the PCRaster Resource Sharing repository. Alternatively you can play with the parameters of the lddcreate algorithm to not fill all sinks.

[@alraschidadam8633]

Hi I was stucked at Upslope Area and it says Error: tool needs graphical user interface [Upslope Area]. I already changed the added "|4" in ta_hydrology_upslope_area and it does not work still.

[@HansvanderKwast]

Better to not use SAGA for this analyis. I've switched to the PCRaster Tools plugin (jvdkwast.github.io/qgis-processing-pcraster/). You can find many videos on this youtube channel on how to use this plugin for stream and catchment delineation and other tasks.

[@pasqualepaldino33]

Could i make last question? How can i set my qgis with sr wgs 84 etrs89 utm zone 33, i make u this question becouse in my sr i do Not have etrs but i have just epgs? By tue way thanks for your video i am learning very much

[@HansvanderKwast]

Your question is not so clear, but maybe the videos about projections can help you. Check it here: kzbin.info/aero/PLeuKJkIxCDj1c0ffAkIb5P1-80lporfbU

[@pasqualepaldino33]

@@HansvanderKwast Mr. Hans thanks very much i have made my project now i have understand my mistakes

[@mahmoudezzat6548]

I'm an Agricultural Engineer from egypt, and I'm excited with GIS technology. My next step will be master degree (GIS in RWH). Can you please support me with some idea to start with Professor. ☺️