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Three models for colloid generation.
\begin{enumerate}
\item Impulse based. \cite{styczen88}
\item\label{morgan} Energy based, with unlimited potential
  storage. \cite{EUROSEM}
\item\label{jarvis} Energy based, with limited storage. \cite{macro-colloid}
\end{enumerate}

Two models for kinetic energy i rain, used by colloid generation
model~\ref{morgan} and~\ref{jarvis}.
\begin{enumerate}
\item Ignoring canopy, default for colloid generation
  model~\ref{jarvis}. \cite{Brown87}
\item Including canopy, default for colloid generation
  model~\ref{morgan}. \cite{EUROSEM}
\end{enumerate}

Three models for the dampening factor of ponding, used by all three
colloid generation models.
\begin{enumerate}
\item One based on canopy height alone. \cite{EUROSEM}
\item One based on both canopy height and droplet size. \cite{Park82}
\item No dampening.
\end{enumerate}

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