Muskingum Routing

Another routing option available within NWSRFS is Muskingum Routing.
Muskingum routing is well documented in hydrology and engineering texts and is a widely used method of storage routing.
It is also based on the storage equation which is an expression of continuity.

The expression for storage in a reach of a stream used in the Muskingum method is:

S = K [ xI + ( 1 - x ) O ]
where

I = inflow rate
O = outflow rate
K, x = storage parameters

To apply Muskingum routing to a reach it is first necessary to determine values for the parameters K and x which are used to describe the storage characteristics of the reach.
Values of K and x are normally derived analytically from historical flood records.
The parameter K is a storage constant expressing the ratio between storage and discharge.
Usually expressed in hours, K may also be viewed as the lag or travel time through the reach.
The dimensionless parameter x is indicative of the relative importance of inflow and outflow to storage.
Like K, it is also referred to as a storage constant.
Although the Muskingum method is not as inherently flexible as the Lag and K method of routing, it is nevertheless quite adequate for many reaches and routing situations.