onlinerouting07:   Clark unit hydrograph 

Formulas

Q = Ij * Ak             Convolution (See text example).

O2 = C0I2 + C1I1 + C2O1        C0 = (Δt/K)/[2+(Δt/K)]

C1 = C0        C2 = [2-(Δt/K)]/[2+(Δt/K)]

Reference

Ponce, V. M. 1989. Engineering Hydrology, Principles and Practices. Prentice Hall, pages 311-313.
Example
INPUT DATA:

Enter unit hydrograph duration tr (hr):               Enter time interval Δt (hr):               Enter storage constant K (hr):     

Enter number of increments of [watershed] drainage area:     

Enter increments of [watershed] drainage area Ak (km2) (separate each value with a comma; maximum string length is 200 characters).

Ak:     

ECHO OF INPUT:

Unit hydrograph duration tr =   hr               Time interval Δt =   hr                Storage constant K =   hr                

Number of increments of [watershed] drainage area =  

Ak  (0) =  .   

OUTPUT:

Time
interval		Time
(hr)		Outflow
(km2-cm/hr)		Outflow
(m3/s)
00  

            

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