Different DEM resolutions result in different stream networks for fixed threshold about taudem

[dtarb]

The AreaDinf function returns its results as specific catchment area. It is the number of grid cells times cell area divided by unit contour length, here estimated as cell size. Let n be area in number of cells, and d cell size. The algorithm reports nd = nd^2/d. I believe that this explains your result.

See https://hydrology.usu.edu/taudem/taudem5/help53/DInfinityContributingArea.html where this is explained in a bit more detail.

Note that his approach is only used with Dinfinity, not D8 Contributing area.

[jeremymatt]

Thanks for the clarification! That makes sense now. I read the helpfile you linked above, but I glossed over the distinction between "area" and "specific catchment area". Assuming it isn't too hard to implement, allowing the user to choose either raw area or specific catchment area would be a nice addition (especially since this operation is not consistent with the D8 area function). Also, adding the information you gave above (that contour length is estimated as cell size and the Aspecific = nd = nd^2/d equation) to the AreaDinf documentation might help clarify the function operation for other inexperienced users.

In the meantime, I'm now confident that my workaround of adjusting the threshold to be a threshold of "specific catchment area" rather than an "area" threshold is valid for my application.