The infiltration rate into a particular soil as a function of time for a steady rainfall rate of $0\mathrm{.}34$

in$./$hr is as follows: $[10$ pts$]$

Assume the equilibrium infiltration capacity $)$ is equal to $0\mathrm{.}116i\frac{n}{h}r.$

Estimate the parameters in Horton's infiltration equation for the soil $(f_{\text{@}}$ and $k)$ and the time to

ponding $(t_p)$ from the following procedure:

$($a$)$ Plot the data $[$f$($t$)$ versus time$].[1$ pt$]$

$($b$)$ You should recognize from Horton's equation that $"f(t)-f_c"$ is an exponential equation which

will plot as a straight line on semi$-$log graph paper. Using Excel, to plot $Ln[f(t)-f_c]$ versus

time $[$use chart type as XY $($Scatter$)],$ add trendline $($show linear equation and $R^2),$ and

determine $k$ from the slope of the trendline. Determine $t_p$ graphically or solve a linear equation

since pts