The contribution of few days ago Where do channels begin ? looks to channels' forming processes. The scientific debate has another side which regards channels network extraction.
A recent paper by Orlandini et al. (2011), whose results where also presented at CATHY meeting last January, presents a concise but nice introduction to the topic, and a few results based on works made in the Dolomites. A parallel introduction can be found in my slides.
Certainly Orlandini and Moretti have the merit to have produced the most cleaned methods to produce channels delineation (all papers cited below), and in parallel, proper methods for estimating the upslope contributing areas of any point in a catchment. This is an essential ingredient of the whole story of proper watershed (and drainage directions) delineation and we implemented most of their work (not all of it unfortunately) in JGrass. The rest is kind of an epiphenomenon.
Orlandini, S., and G. Moretti (2009a), Determination of surface flow paths from gridded elevation data, Water Resour. Res., 45, W03417, doi:10.1029/2008WR007099.
Orlandini, S., and G. Moretti (2009b), Comment on ‘‘Global search algo- rithm for nondispersive flow path extraction’’ by Kyungrock Paik, J. Geophys. Res., 114, F04004, doi:10.1029/2008JF001193.
Orlandini, S., Tarolli, P., Moretti, G., Dalla Fontana, G. (2011). On the prediction of channel heads in a complex alpine terrain using gridded elevation data, Water Resources Research, 47, W02538, doi:10.1029/2010WR009648