Tutorial 6
Question 1
A catchment generates the following direct runoff (DRO) hydrograph (following Table) from a 2.5-minute
storm event with rainfall excess intensity of 24mm/hr. What is the area of the catchment (in hectares)?
What will be the peak discharge (in m3/sec), time to peak (in minutes) and time base (in minutes) of the
5-minute unit hydrograph for this catchment?
Question 2
What will be the reduction in peak discharge (expressed as percentage relative to the inflow hydrograph)
and the delay in time to peak (in minutes) if the storm hydrograph given in above Table from Q1 travels
through a channel with K = 5 min and x = 0.1? Sketch the inflow and outflow hydrographs showing all
salient features.