Resulting Hydrograph from Staggered 4 Hour Unit Hydrograph

When adding a 4-hour unit hydrograph to itself with a 4-hour time lag, the resulting hydrograph will demonstrate how the flow changes with time.

Process of Adding Staggered 4 Hour Unit Hydrograph

The process of adding a staggered 4 hour unit hydrograph involves the following steps:

1. Draw the first 4-hour unit hydrograph as a curve on a graph paper.
2. Draw the second 4-hour unit hydrograph on the same graph paper but shifted to the right by 4 hours.
3. Add the ordinates of the two hydrographs at each time interval to get the resulting hydrograph.

Characteristics of Resulting Hydrograph

The resulting hydrograph will demonstrate the following characteristics:

1. The peak flow will occur 4 hours after the peak of the first hydrograph.
2. The peak flow will be higher than the peak of the first hydrograph.
3. The rising limb of the resulting hydrograph will be steeper than the first hydrograph.
4. The falling limb of the resulting hydrograph will be flatter than the first hydrograph.
5. The time to the peak will be longer than the first hydrograph.

Conclusion

In conclusion, adding a staggered 4-hour unit hydrograph provides an effective way of predicting the flow of a river or stream. It enables us to accurately predict the peak flow and the time to the peak. By understanding the characteristics of the resulting hydrograph, we can make better decisions regarding flood control measures and water management.