TO DEVELOP STORM HYDROGRAPH FROM UNIT HYDROGRAPH
- The unit hydrograph of a specifie unit duration can be easily use to develop the hydrograph of storms of the same duration.
- The total volume of run-off (in cm) resulting from a storm when divid by 1 cm will give the multiplying factor i.e.
- the factor by which the ordinates of the unit hydrograph must be multipli in order to obtain the ordinates of storm hydrograph of the same duration.
- The following example illustrates the method by which storm hydrograph is develop from unit hydrograph of the same duration. Example 6.2. Date, time, ordinates of unit hydrograph and base flow are given as follows.
- Determine the ordinates of direct run-off and total discharge ordinates. Rainfall excess is 10 cm. Time of duration is 6 hrs.