53:119 Hydrology
Problem #21
Rainfall Excess based on f-index for the NB Ralston Creek (July 1972 storm)

Compute the rainfall excess (direct runoff) for the North Branch Ralston Creek watershed (drainage area of 3.01 sq mi) for 17-18 July 1972 storm using the f-index method. Use the areal-average precipitation estimated using the Thiessen Polygon method (this is provided). Assume that the f-index is 0.50 in/hr. Compute the following:

  1. Total storm precipitation (in inches)
  2. Rainfall intensity (i) hyetograph (in in/hr)
  3. Rainfall excess (Pe) hyetograph (in inches)
  4. Depth of direct runoff (rd) (in inches)
  5. Volume of direct runoff (Vd) (in acre-feet)
  6. Effective storm duration (tr) (in hr)
  7. Runoff coefficient (C)
Last changed on 10/15/13 by aab.