Question $2$It is required to design a culvert at the outlet of the attached catchment area, find out the maximum amount of runoff. The following data will be helpful for your calculations:The catchment area can be divided to three sub areas, each have a runoff coefficient as indicated on the Figure.To imply the rational formula, the area of the sub$-$catchment should not exceed $25$ km$?$Maximum precipitation $=21$ cm $($for year $1982)$Design for a return period is $15$ yearsMaximum storm period $=2$ hours $($from the above tables$)$Use Kirpich's formula to find time of concentrationEach cell is $1$ km x $1$ kmFind the runoff by finding the intensity by $(1)$ using the Intensity Duration Curve obtained in question $1$ and $(2)$ using the formulas