Question

The following steps are involved in arriving at a unit hydrograph:

The correct sequence of these steps is

• A. 3, 2, 1, 4
• B. 2, 3, 4, 1
• C. 3, 1, 2, 4
• D. 4, 3, 2, 1

Answer 1

The correct option is A 3, 2, 1, 4

The separation of base flow gives direct runoff hydrograph (DRH). The area under the DRH gives volume of surface runoff. The effective depth of precipitation can be obtained by using $\varphi -$ index or volume of surface runoff can be divided by the catchment area. Finally the ordinates of UH can be obtained by dividing the ordinates of DRH by effective depth of precipitation.