DRH of a Storm with 3H of Effective Rainfall and 6 cm of Direct Runoff

The DRH (Direct Runoff Hydrograph) of a storm can be defined as the graphical representation that shows the variation in flow rate over time for the direct runoff component of a hydrological event. In this case, we are given a storm with 3 hours of effective rainfall and 6 cm of direct runoff.

Calculation of DRH Ordinates

To calculate the ordinates of the DRH of this storm, we need to follow the steps below:

1. Determine the total volume of runoff
- The total volume of runoff can be calculated by multiplying the effective rainfall by the catchment area. In this case, we are not given the catchment area, so we cannot calculate the total volume of runoff.

2. Determine the time of concentration
- The time of concentration is the time taken for the water to travel from the furthest point of the catchment to the outlet. It is an important parameter in the calculation of the DRH. In this case, we are not given the time of concentration, so we cannot calculate the DRH.

3. Determine the time base of the DRH
- The time base of the DRH is the time interval between successive ordinates on the hydrograph. It should be chosen based on the characteristics of the catchment and the storm. In this case, we are not given the time base, so we cannot calculate the DRH.

4. Determine the peak discharge
- The peak discharge is the maximum flow rate on the DRH. It is an important parameter in the design of hydraulic structures. In this case, we are not given the peak discharge, so we cannot calculate the DRH.

Conclusion

In conclusion, we cannot calculate the DRH ordinates of the storm with 3 hours of effective rainfall and 6 cm of direct runoff because we are not given the catchment area, time of concentration, time base, or peak discharge. These parameters are all essential in the calculation of the DRH and cannot be estimated without further information.

When divided by 6 give the ordinates of a 3-h unit hydrograph