Burkli Ziegler Formula
Burkli Ziegler formula is the oldest formula used to determine the peak runoff rate. It was derived by a swiss engineer for local conditions. After that, it was followed in the whole U.S.A.
In M.K.S unites it states that
► = The peak runoff in cumecs.
► = Runoff coefficient (Depending upon the permeability of the surface), and the average value is taken as 0.7.
► p = The maximum rainfall intensity over the entire area( Usually the value is taken as 2.5 to 7.5 cm/hr.
► A = Drainage area in hectares.
► S0 = The slope of the ground surface in meters per thousand meters.