附录中图表重新编号

\setcounter{figure}{0}      %设置编号

\begin{appendix}    %插入appendix环境，此处似乎用\appendix也行

    \renewcommand{\thefigure}{A\arabic{figure}}

\section{Supplementary material}

\begin{figure}[htpb]

    \centering

    \includegraphics[width=0.6\linewidth]{gg_insitu_light}

    \caption{Variation of light intensity at different

            depth (light intensity in \si{\lunit}).}

    \label{fig:lightdepth}

\end{figure}

\end{appendix}

参考：

https://tex.stackexchange.com/questions/85776/change-figure-numbering-for-appendix

https://zhuanlan.zhihu.com/p/37875669

http://lg-zhou.blog.163.com/blog/static/178068920118243754271/