Ridge-River Network
Finding the Ridge Network: This is done by simply inverting the terrain and running the drainage network. This is a Simple, fast and effective method. Often compression techniques smooth out ridges. Having an accurate representation of the ridge network can assist compression algorithms and also has applications in siting, path planning and hydrology.
Ridge-River Network: The ridge-river network is defined as the union of the drainage network and the ridge network.
Below is a visual of the ridge-river network. Dark blue shows low elevations, while dark red corresponds to high elevations.
CODE: This code computes both the drainage network and the ridge network using a linear system that determines that amount of flow for each cell in a DEM. To run this code you must have both the g++ compiler and Matlab. (.zip) or (.tgz)
For Ridge-River Constrained Triangulation the code is available here (zip)