Is there an ArcGIS-like implementation of Flow Accumulation for R?
What I am trying to avoid: Using ArcGIS; Using Grass; Using RpyGEO (but will if need be)
I am aware of the landscape/hydrology packages of RSAGA, enaR, and vegan, but none of these seem to have a flow accumulation function. I have seen previous reference to rsaga.flow.accumulation, but that does not appear to be support any longer.
I have tried ??flow, but only the RPyGEO and a flow path from the Raster package show any promise.
Furthermore keep in mind, that flow accumulation is a very expensive raster calculation and R is definitely not the right tool for that. Thats probably also the reason, why there is no R package doing that.
– mace Jan 29 '14 at 20:05Rto go from a raw DEM to the flow accumulation? The tricky part is creating the flow direction grid; after that, a (very simple) graph algorithm does the trick. (And, for performance reasons, you wouldn't want to code that inRif you could help it.) See the recent discussion at http://gis.stackexchange.com/questions/84309/what-algorithm-is-used-by-arcgis-watershed-tool, which includes a link to an on-line version of the original Jenson and Domingue paper (1988). – whuber Jan 29 '14 at 20:48rsaga.fill.sinkscomputes a flow direction using either Planchon and Darboux (2001) or Wang and Liu (2006) [it is only one of those, but the doc says "only for "wang.liu.2001"]. The consensus seems to be thatRis a poor choice for this. I see the reason of that argument and they outweigh my desire to contain it withinR; I will use python for those bits. Thanks for the help/info! – Mr.ecos Jan 29 '14 at 21:15Rattractive is that you could encapsulate the part of the algorithm that is not good forRand code it in C or Fortran, which are relatively easy to interface withR. This viewsRas a kind of rapid prototyping platform which can fairly easily be turned into a production environment. – whuber Jan 29 '14 at 21:27