I have an very hard task I want to do in QGIS (or another open source GIS program).
I have point data for river bathymetry (depth). I have been creating digital elevation models of them using Grass and masking the river which makes them look gorgeous but I can tell that there are some issues, just logically. GRASS is interpolating in a North-South East-West Grid, which is not he direction the river runs in! The river meanders and turns and the bathymetry must be interpolated accordingly.
The goal would be to draw a line down the center of the river and use that as a guide for the interpolation (to interpolate outwards from the line). I have seen a nice lecture where a professor mathematically straightened the line using a datum and creating a "straightening" equation and then applying it. The interpolation was then done in the traditional way but at the end the river was re-curved. I did not 100% understand it.
Other things worth mentioning are that ideally this software would interpolate new cross sections (Can this be done in HEC-RAS?) I am pretty sure software such as Mike-11 or Mike-Something more advanced can do this but looking for an open source solution.
The questions are:
Does there exist a tool for this currently?
How could I go about creating a tool for this? (Python plugin)?