Muskingham method of flood routing is:

Concept:

Muskingham’s method is the most common hydrologic method of channel routing in which the channel storage in a reach is expressed as a function of both inflow and outflow discharge.

\({\bf{S}} = {\bf{k}}\left( {{\bf{x}}{{\bf{I}}^{\bf{m}}} + \left( {1 - {\bf{x}}} \right){{\bf{Q}}^{\bf{m}}}} \right)\)

Where,

S = Storage in a channel reach, I = Inflow discharge, O = Outflow discharge, and k = Storage time coefficient

It has a unit of time and it is approximately equal to the time of travel of flood wave through the channel reach.

x = Weightage factor. Its range varies from 0 to 0.5.

m= 1, for naturally occurring channels.