DESCRIPTION

OPTIONS

dirs
Flow direction: name of input direction map produced by r.watershed or r.stream.extract. If r.stream.extract output map is used, it only has non-NULL values in places where streams occur. NULL (nodata) cells are ignored, zero and negative values are valid direction data if they vary from -8 to 8 (CCW from East in steps of 45 degrees). Direction map shall be of type CELL values. Region resolution and map resoultion must be the same.
elevation
Elevation: name of input elevation map or any other map we want to calculate . Map can be of type CELL, FCELL or DCELL. It is not restricted to resolution of region settings like dirs.

OUTPUTS

difference
Downstream elevation difference: Difference between elevation of current cell and downstream cell. Shall always be posivtive. Negative values show, that current cell is pit or depression cell. Module is prepared to be used with elevation but can be also used to calculate local difference of any feature along watercourses in slope subsystem. In that way elevation map must be replaced by map we want to calculate. If we use different map than elevation, rest of parameters have no sense to calculate
gradient
Downstream gradinet: Downstream elevation difference divided by distance.
maxcurv
Maximum linear curvature along watercourse. Calculated along watercourse between highest upstream cell, current cell and downstream cell (there can be only one or no downstream cell but more than on upstream)
maxcurv
Calculated along watercourse between lowest upstream cell, current cell and downstream cell (there can be only one or no downstream cell but more than on upstream)

SEE ALSO

r.watershed, r.stream.extract, r.stream.order, r.stream.basins, r.mapcalc,

AUTHOR

Jarek Jasiewicz, Adam Mickiewicz University, Geoecology and Geoinformation Institute.

Last changed: $Date$