The two panels in \autoref{fig:CarrierGreenspan_default_fig1.eps} compare the XBeach results with the analytical solution. The agreement should be reasonably well, though there are small deviations in the water level near the water line and the flow velocities seem to lag slightly on the analytical solution during the second part of the run down. Since the analytical solution is stationary, numerical output over multiple waves is shown in \autoref{fig:CarrierGreenspan_default_fig1.eps}, verifying that also the numerical solution is reasonably stationary.
Carrier, G.F., and Greenspan, H.P., \emph{Water waves of finite amplitude on a sloping beach}. Journal of Fluid Mechanics, 1958, vol. 4, 97 - 109