1. Plot the SWRC (suction vs. volumetric water content) from the van Genuchten (1980) model for the following “base-case” parameters (assume m = 1-1/nvG): alpha vG = 0.35 kPa-1, nvG = 2.2,Delta res = 0.02, and delta S = delta sat = 0.45. These values are approximately representative of a sand.Perform a sensitivity analysis on each of the base case parameters (i.e., vary each by ±10% while holding the other three constant) to determine their relative effects on the SWRC. For example, how would a change in s alter the curve if the other base case parameters stay the same? In your answer, provide 4 plots for the parametric evaluation of each parameter as well as a brief qualitative explanation for each plot (for example, when investigating the effect of alpha vG, show the base-case curve and the curves with different values of alpha vG on the same plot). Be sure that suction is plotted on a logarithmic scale. Also, discuss how theparameters of the van Genuchten SWRC model might differ for a clay.

1. Plot the SWRC (suction vs. volumetric water content) from the van Genuchten (1980) model for the following “base-case” parameters (assume m = 1-1/nvG): alpha vG = 0.35 kPa-1, nvG = 2.2,
Delta res = 0.02, and delta S = delta sat = 0.45. These values are approximately representative of a sand.
Perform a sensitivity analysis on each of the base case parameters (i.e., vary each by ±10% while holding the other three constant) to determine their relative effects on the SWRC. For example, how would a change in s alter the curve if the other base case parameters stay the same? In your answer, provide 4 plots for the parametric evaluation of each parameter as well as a brief qualitative explanation for each plot (for example, when investigating the effect of alpha vG, show the base-case curve and the curves with different values of alpha vG on the same plot). Be sure that suction is plotted on a logarithmic scale. Also, discuss how the
parameters of the van Genuchten SWRC model might differ for a clay.