Using the rainfall data below, determine the rainfall excess and total volume of runoff for this

storm in the Williamson River watershed. You will first need to compute and plot the infiltration

rate and cumulative infiltration at $0\mathrm{.}20-hr$ increments up to $4$ hours from the beginning of

infiltration using the following methods:

Green$-$Ampt method. Soil type in the Williamson River watershed is a loam. Assume an

initial effective saturation of $70\%$ and continuous ponding.

Horton method. For our study watershed, the parameters for Horton's equation are fo $=$

$0\mathrm{.}88i\frac{n}{h}r,fc=0\mathrm{.}15i\frac{n}{h}r,$ and $k=2\mathrm{.}5h-1.$ Assume continuous ponding.

$-$ index method. $$ has been found to be $0\mathrm{.}11i\frac{n}{h}r.$

Once infiltration is found and plotted, rainfall excess will be the difference between the rainfall

amount and infiltration.

Comment on the different methods. How accurate do you think they are? Which one would you

recommend using and why?

$**$ if you use a spreadsheet to do this homework, provide the equations that were used and a

sample calculation for each equation used$**$