Chapter $7$ Infiltration

$7\mathrm{.}9$ Tabulated below are total rainfall intensities during each hour of a frontal storm over a drainage basin.

a$.$ Plot the rainfall hyetograph $($intensity versus time$).$

b$.$ Determine the total storm precipitation amount in inches.

c$.$ If the net storm rain is $2\mathrm{.}00$ in$.,$ determine the exact $$ index $($in$./$hr$)$ for the drainage basin. $($Note that by definition the area under the hyetograph above the $$ index line must be $2\mathrm{.}00$ in$.)$

d$.$ Determine the area of the drainage basin $($acres$)$ if the net rain is $2\mathrm{.}00in.$ and the measured volume of direct surface runoff is $2,015cfs-hr.$

e$.$ Using the $$ index calculated in part $c,$ determine the volume of direct surface runoff $($acre$-$ft$)$ that would result from the following:

$\backslash$table$[[$Hour$,1,2,3,4],[$Intensity $($in$./$hr$),0\mathrm{.}40,0\mathrm{.}05,0\mathrm{.}30,0\mathrm{.}20]]$