Table P$1-21$

Problems $1\mathrm{.}22$ and $1\mathrm{.}23$ refer to the hydrologic data used in Problem $1\mathrm{.}21.$

$1\mathrm{.}22.($a$)$ Plot the cumulative mass curve for rainfall and the hydrograph $($flow rate

vs$.$ time$)$ on the same graph using two scales.

$($b$)$ Compute the volume of infiltration loss for the storm, neglecting ET

by subtracting the volume of gross rainfall from the volume under the

hydrograph.

$1\mathrm{.}23.$ What is the runoff coefficient for the September $1,1999$ storm, where

Coeff. $=\frac{R}{P}?$