How can I prepare data to generate a DTM using points and breaklines, but where every breakline has nodes at different heights. For example, a river valley, which regularly falls, or a dorsal line, where each vertex is a different height.

Thanks for the answer. Tom


From my point of view, break lines are lines with very different values on each sides (e.g. cliffs), so I would not consider a river as a break line.

I would suggest that you use a TIN interpolation, with your lines used as "structure lines" and checking the "use Z coordinates" (assuming your lines have Z values)

Note : I assume that you use the Interpolation plugin

  • That's what I'm talkimg about! No rivers or clifs has equals altitude along structural lines. I'll be testing that option "use Z coordinates" soon. Thanks. – tomsik Feb 25 '14 at 7:54

I think that the default behavior for breaklines is that they do follow a valley bottom, or ridgeline. See this for example: http://support.esri.com/en/knowledgebase/GISDictionary/term/breakline

What you're asking is that a line can include specific height values on each vertex along the line, and I don't know of any GIS products that do this. You'd need points at each vertex, and a line as a breakline that follows these vertices, I reckon.


Consider convert those lines to points, then run the interpolation.

  • Welcome to GIS SE! As a new user please take the tour to learn about our focused Q&A format. A good answer should include an explanation as to how to perform the steps in your answer, and what they do to solve the problem. Please edit your answer to include more detailed information. – Midavalo Jun 14 '17 at 18:00

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.