0

I have a river and a field next to it (with its DEM). I want to determine the water's pathways in the field, when the water in the river reaches a certain level , based on the DEM only.

I am thinking of using r.lake but it only uses one point as a seed?

Obviously a more precise hydraulic modelling of the river inundation is needed but I just want to have an idea of the pathways.

1 Answer 1

0

By your own admission this is an exercise in futility. What you need is a proper hydraulic model. Consider HEC-RAS (freeware).

Generating a detrended surface models (some call it a relative elevation model) might get you a vague idea of the flow of water at different water heights but again, this is not a peer-reviewed excepted practice filled with potential error. Here a link to detrending in QGIS using IDW interpolation.

You don't ask for it but here is a suit of ArcGIS 10.7 toolbox tools using several different methods for detrending. There is also an transect (IDW) tool for ArcGIS Pro.

1
  • Thanks for the reply. I was asked to avoid using HEC-RAS due to time constraints and low stakes of the study so I am looking for a tool to get a rough idea of the water pathways in QGIS.
    – user38646
    Commented May 12, 2023 at 15:19

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

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