The ordinates of a flood hydrograph of 2-hour storm is given as follows:
|
Time (hour) |
0 |
2 |
4 |
6 |
8 |
10 |
12 |
|
Ordinate (m3/s) |
3 |
7 |
12 |
15 |
11 |
5 |
3 |
If the storm generates 4 cm of excess rainfall and the base flow is 3 m3/s, then the peak ordinate of a 4-hour DRH with excess rainfall of 2 cm is _______.
1
6.75 m3/s
2
4.75 m3/s
3
3.25 m3/s
4
5.25 m3/s