====== Mulvaney Equation ====== The Mulvaney Equation was proposed by the Irish engineer Thomas James Mulvaney (1822-1892). The equation was first published in 1851. The model predicts the peak discharge $Q$ as a function of an empirical constant $C$, the average rainfall intensity of the catchment $I$ and the area of the catchment $A$: $$Q [m^3/s] = C \left[\frac{1E+6}{1E+3*3.6E+3}\right] * I \left[\frac{mm}{hour}\right] * A [km^2]$$ The intensity being given in $mm/hour$ and the area in $km^2$, the constant $C$ accounts for the transformation of units from $mm/hour$ and $km^2$ to $m^3/s$. This equation is only valid for small catchments in which storage and losses are not significant! This rather the case in urban (small) catchments: This equation in commonly used units reads: $$Q_{peak} = 0.278 * C * I * A$$ where $Q_{peak}$ = peak discharge in cubic meters per second $I$ = Intensity of rainfall in mm/hour $A$ = Area in square kilometers $C$ is a runoff coefficient.