**RATIONALE**
Fon a chosen Courant number C and number of linear reservoirs N, there is a unique dimensionless unit hydrograph based on the cascade of linear reservoirs.
The dimensionless unit hydrograph has dimensionless time t_{*} as abscissa and dimensionless discharge Q_{*} as ordinate.

The dimensionless time is t_{*} = t / t_{r}, in which t_{r} is the duration of the unit hydrograph, in hours.

The dimensionless discharge is Q_{*} = Q / Q_{m}, in which Q_{m} = 2.777778 (A / t_{r}), is the maximum attainable discharge
(runoff concentration only), in m^{3}/s.
In this formula, basin area A is in km^{2}; unit hydrograph duration t_{r} is in hours.

The dimensionless unit hydrograph is independent of unit hydrograph duration t_{r} and reservoir storage constant K, and is dependent only on their ratio C = t_{r} / K.
The dimensionless unit hydrograph is independent of the basin area A.