Delmarva Unit Hydrograph
Qp = 284 * A / Tp
Qp = peak flow rate in cfs.
A = area of the watershed, in square miles, draining to the location of the unit hydrograph.
Tp = time to peak of the unit hydrograph in hour
Time to peak, and lag time are calculated according to Equations 97 and 98, respectively. When compared with the NRCS methods, the Delmarva unit hydrograph produces lower peak flow rate but yields the same flow volume.
The Delmarva unit hydrograph uses the following equation to estimate the peak flow rate.