This article refers to:

r.traveltime


The estimation of the fdis factor for scaling the excess precipitation is not trivial because there aren't any comparative values available. I've concluded that this calculations are not suitable for flood modeling. The input values "Excess precipitation" and "fdis" are replaced by the mean specific discharge of floods. The value can be obtained by statistical evaluation of observations. Moreover you can assume that this value is also valid for unobserved basins in the vicinity (200 l/s/km**2 is a good guess for mid latitude basins, maybe higher in mountainous basins). The new version is available for testing:

r.traveltime.tar.gz