## Parameters

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.

## Examples

### 1.

#MEDIUM_PROPERTIES
$SURFACE_FRICTION 66.67 0.5 0.67 ... #STOP  ## Documentation from doxygen None. ## Used in benchmarks ### COUPLED_FLOW/Wool_lines_coup.mmp  3:$SURFACE_FRICTION
4-    1333333 1. 2.
...


  5:   $SURFACE_FRICTION 6- 6.67 0.5 0.667 ...  ### COUPLED_FLOW/abdulLab.mmp  39:$SURFACE_FRICTION
40-    5.39 0.5 0.66667
...
142:   $SURFACE_FRICTION 143- 5.39 0.5 0.66667 ... 167:$SURFACE_FRICTION
168-    5.39 0.5 0.66667
...
192:   $SURFACE_FRICTION 193- 5.39 0.5 0.66667 ... 221:$SURFACE_FRICTION
222-    1333333 1. 2.
...


  3:   $SURFACE_FRICTION 4- 430000 1. 2. ...  ### OVERLAND_FLOW/gian_quad.mmp  5:$SURFACE_FRICTION
6-    66.67 0.5 0.67
...
12:   $SURFACE_FRICTION 13- 6.67 0.5 0.67 ...  ### OVERLAND_FLOW/gian_tri.mmp  3:$SURFACE_FRICTION
4-    66.67 0.5 0.67
...
8:   $SURFACE_FRICTION 9- 6.67 0.5 0.67 ...  ### OVERLAND_FLOW/govin_line.mmp  3:$SURFACE_FRICTION
4-    18.25 0.5 0.67
...