FYI,
r.watershed in GRASS 7 can now also calculate a topographic
convergence index (TCI) including true MFD TCI after Quinn et al.
(1991), taking into consideration the flow convergence factor after
Holmgren (1994).
The edge artefacts in SFD mode have been removed, streams no longer
creep along edges.
For the segmented mode (-m flag), the supported maximum number of
cells has been increased from 2^31 - 1 (about 2 billion) cells to 2^63
- 1 (about 9 billion billion) cells.
Markus M