It calculates the drainage directions with the method of the
maximal steepest descent slope, choosing it among 8 possible directions around the selected pixel.
Inputs
- the file containing the matrix of elevations (obtained with pitfiller)
Output
- the file containing the matrix of the drainage directions
Notes
The maximal slope direction is chosen among the 8 possible directions
and codified with numbers ranging from 0 to 8. Such method derives from the one originarily used by D. Tarboton in his Phd thesis. However the outlets are marked with value 10 (beware: many other programs assume it).