Last modified 3 years ago Last modified on 08/04/15 10:10:00


The keyword $SURFACE_FRICTION is applied to define the surface roughness of a slope or that of a channel, which is important for the surface runoff process. This keyword can be used in the process overland flow.


double double double

The reciprocal of the first parameter is the Manning friction, whereas different combinations of the second and the third parameters can result in different model approaches (e.g. Darcy-Weisbach). In the example given below, the manning friction is given by the reciprocal of the first value i.e. 0.015 s/m1/3, the combination of the second and the third value result in the relationship by Manning.



  66.67 0.5 0.67