Did you know that TopoToolbox has a function to identify knickpoints in river profiles? Well, if you don’t know, now you know.
The function is called knickpointfinder. It uses an algorithm that adjusts a strictly concave upward profile to the actual profile. Offsets between the actual and the concave upward profile occur where the actual profile has convexities. Relaxing the concavity constraint where offsets attain a maximum will adjust the concave profile to the actual profile. knickpointfinder adjusts the profile iteratively until offsets fall below a specified tolerance value. Look at the animation below which probably explains more than a thousand words.
Using knickpointfinder is easy. Just see the function help to run the example whose results are shown above.
Let us know how well knickpointfinder suits your needs. Note that this algorithm is not yet published, so please give credits to our TopoToolbox paper if you are using this algorithm in your work.