General description

You can chose between two ways of describing the bed resistance in the MIKE 21 Flow Model: either as a Chezy number or as a Manning number. In both cases the bed resist­ance used is

(6.1)   

where g is gravity, u is velocity and C is the Chezy number. Manning numbers are converted to Chezy numbers as follows

(6.2)   

where M is the Manning number and h is the water depth. The units of Chezy numbers and Manning numbers are respectively m^1/2/s and m^1/3/s.

Please note that the Manning number used in MIKE 21 is the reciprocal value of the Manning number described in some textbooks.