\begin{figure}[!htbp]
\begin{center}
\includegraphics[width=1.0\textwidth]{figures/richards/k_fun.png}
\end{center}
\caption{
    The hydraulic conductivity function showing bounds of the various parameters
    $K_s \in [1\times 10^{-7}, 1\times 10^{-4}]$, $\alpha \in [2.5, 13.5]$, and $n \in [1.1, 1.6]$
    for four canonical soil types of (a) sand, (b) loam, (c) sandy clay, and (d) clay.
}
\label{fig:richards-k_fun}
\end{figure}
