Hydrology and Runoff

The S-curve technique is used to convert a unit hydrograph of duration $D_1$ into a unit hydrograph of duration $D_2$ when:

Options:

• (A) $D_2$ is any arbitrary duration (not necessarily an integer multiple of $D_1$)
• (B) $D_2$ is strictly twice $D_1$
• (C) Peak discharge is zero
• (D) Rainfall occurs instantaneously