Using the Profile Tool plugin in QGIS

[@barenddejong5474]

Used it for years. One of the best plugins

[@michaelgetachewtadesse9678]

Thank you Hans, your former student from IHE

[@innocentndagijimana6816]

Thank you Mr. Hans for opening skills to us!

[@rodglen7071]

One problem that some people have is the "Selected Polyline" option. You have to use the select tool internal to the plugin, which in effect acts as the QGIS select tool, but I've noticed that you can't just pre-select the line in Q - you have to use the Profile Tool selection icon. Struggled with this for a long time. Hope that helps others.

[@RazvanPloscaru]

Hi! I've done some lines without have selected a layer, and now I can't delete them anymore. What to do?

[@DiegoAndresAlvarezMarin]

Hans, how can I change the units of the height and the horizontal axis in the profile plot?

[@bbase322]

What if your footage is off. How would you fix that?

[@hereditarist]

thanks from Turkey

[@cptlemartes]

Double click to specify the end of the line! Saved my bacon! 😆😅

[@siyuwang692]

Thank you! But I have a question that how to delete the profile I plot?

[@HansvanderKwast]

It's linked to the line that you made in the map canvas. If you click right, the line will be removed and you can make a new profile.

[@siyuwang692]

@@HansvanderKwast Thanks a lot !~

[@pasqualepaldino33]

Thanks Mr. Hans i have an issue concerning the x scale, when i track a profile the x scale is in logartmic i would want change it in Meters how could i di?

[@HansvanderKwast]

It is in map units. In my video you see the x units in meters, because I use a UTM projection. You probably use EPSG: 4326 lat/lon coordinates. The solution is to reproject. That's highly recommended if you want to use the DEM for analysis, see kzbin.info/www/bejne/kH24m4Z7gJKhmMk

[@JALAJDARPAN]

did you find solution.even im getting same issues

[@pasqualepaldino33]

@@JALAJDARPAN thanks Mr Hans i found solution. Make sure to click utm so the program can consider meters and not "angle".

[@JALAJDARPAN]

@@pasqualepaldino33 thank you

[@federicolopezbervejillo7995]

Perfect. I tried and is very useful. Tanks! I have one question, may be you can point a newbie to the right direction: is there a way to place marks in the path profile, let's say every 100 m, and a label with the distance from the start so there's a visual reference between the path in the map and the generated profile?

[@HansvanderKwast]

Instead of drawing the temporary line from the Profile Tool, you can also indicate a polyline vector to be used. If you want labels, you can use the Points along geometry tool from the toolbox to add points at fixed distances and then visualise with the labels. Note that the profile and the line are linked if you hover your mouse over them.

[@federicolopezbervejillo7995]

@@HansvanderKwast I'm trying to generate a printed version of a profile for a multiline path. I think distance marks for correlation is very important. I'll try your suggestion. Thank you!

[@cristianescobar9540]

excellent, very clear !

[@bagusindoholland]

Hi, Hans. I have an issue with the measurement unit of X axis when plotting the longitudinal profile. It is not in meters. I don't why this happen. What I have done are: 1. I convert the projection of DEM from EPSG 4326 to certain UTM zone (in this case, EPSG 32749 - WGS 84 /UTM Zone 49S) 2. I also convert the projection of the river polyline layer to EPSG 32749 - WGS 84 /UTM Zone 49S as well. What should I do to fix this issue? I use QGIS 3.28.9 Firenze

[@HansvanderKwast]

Could it be that your project projection (On-the-fly reprojection) is still on EPSG:4326?

[@bagusindoholland]

@@HansvanderKwast yes, I realized that the projection is still on EPSD:4326. Thanks. Solved. Case is closed.

[@geoguys1186]

Hi thank you for your video, i've tried to download profile tool as explained but and receive error message ssl, what can i do?

[@HansvanderKwast]

Maybe just click ignore and retry: gis.stackexchange.com/questions/266705/custom-certificate-configuration-error-message

[@MattAztig]

Hello sir, great video. But how do you make multiple sections at the length of the whole river?

[@HansvanderKwast]

You can use a vector file with lines at the sections that you want. Those lines can be used to create the sections.

[@MattAztig]

@@HansvanderKwast Thank you! Could I suggest that you make a video like that too?

[@n8dawg640]

Thanks for the video! Is there a way to do this in a 3D area instead of a 2D profile?

[@HansvanderKwast]

Not that I'm aware of. But this video shows a way to add 3D information and uses another profile tool: kzbin.info/www/bejne/mIqsmIZogdpki6M

[@manglem10]

Can such profile be prepared for image representing LST?? I want to show the LST variation across a city and its surrounding area???

[@HansvanderKwast]

Sure. For the tool it doesn't matter if it's a DEM or an LST raster.

[@manglem10]

@@HansvanderKwast thank you! How can one calculate urban island effect from lst?

[@HansvanderKwast]

@@manglem10 For that you need to look at the scientific literature. scholar.google.nl/scholar?hl=nl&as_sdt=0%2C5&q=urban+heat+island+gis&btnG=

[@redgisdc2826]

Interesting video. Those functions are in Google earth. Now how can i get this version of QGis?

[@HansvanderKwast]

Just download the current version from www.qgis.org

[@simonebrotto1977]

Hi Hans, in a mountain area, starting from a DTM and straight line how do I calculate the real length of the line? In field calc $length gives me the projection on the horizontal; but real length, the one which runs through DTM's variations, is bigger. Profile tool gives me XY table, I can save it as DXF, go to Autocad and read polyline length. I could also use Saga's "profile from lines" which creates a vector of points, the last one gives me more or less the real length. Any other tool? What about Grass? Thank you!

[@HansvanderKwast]

I only know the SAGA tool for that, which you mentioned. Currently Lutra Consulting is having a crowd funding, which includes a profile tool, see www.lutraconsulting.co.uk/blog/2021/11/02/pointcloud-qgis/

[@simonebrotto1977]

@@HansvanderKwast is there an equivalent of Saga's "profile from lines" in Grass? Thanx for Lutra's link

[@HansvanderKwast]

Sorry. I don't know.

[@kalm1531]

Well done man!

[@skothe3991]

nice video.....how to convert profile into shape file ???

[@HansvanderKwast]

In fact it's the other way around: you digitize a polyline and you indicate in the Profile tool to use the line for the profile.

[@elifromtheblacksea]

Thank you! :)

[@mohamedelfeki3975]

Thank you