If a unit hydrograph shows how a river responds to one inch of rain, how would you use it to find the river's response to three inches of rain?

A unit hydrograph is a graph that shows how a river's discharge, or flow rate, changes over time in response to one unit of effective rainfall falling uniformly over a specific drainage basin for a specified duration. The term "effective rainfall" refers to the portion of total precipitation that actually contributes to surface runoff, after accounting for losses such as infiltration into the ground, interception by vegetation, and evaporation. The output of the unit hydrograph is a hydrograph, which is a plot of discharge versus time. To find the....