A recent article published in the Journal of Archaeological Science (http://dx.doi.org/10.1016/j.jas.2010.11.006) proposed a method where hydrology models could be used on the product of a cost surface analysis to create a network of paths (instead of just the one made with r.drain -d). The flow accumulation map would represent the number of cells in the map from which a least-cost path would pass through that cell. ie. a flow accumulation of 100 means that 100 cells would have a LCP that would pass through that cell. You could also calculate mobility basins (like a watershed), etc.
This is great extension of cost surface analysis except that I don't think it can be done in GRASS right now. r.cost and r.walk produce a cumulative cost surface and a "flow" direction surface, but if I'm right r.terraflow can't take them as inputs because it calculates everything "in-house". I was hoping someone could double-check my logic on this or perhaps suggest an alternative hydrology module(s) which could take the direction surface as an input instead of calculating everything from the elevation surface. Cheers, Colin _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
