<%namespace name="tools" file="tools.tex"/>

The purpose of research programme LIP 11D was the generation of high quality and high resolution data on hydrodynamics and sediment transport dynamics on a natural 2DV beach
under equilibrium, erosive and accretive conditions. In total 7 tests were performed in the Delta Flume of WL | Delft Hydraulics in the period of April 1993 till June 1993. Test 2E is incorporated in the skillbed, because the profiles and hydraulic conditions in this test correspond rather well to the Dutch situation. Since there is no direct agreement with the reference profile, scale factors or steepness factors cannot be determined in a similar way as in the research programmes in the 1980’s. We assume a scale factor of 1:5. The wave board in the Delta Flume was equipped with active reflection compensation (ARC) at the time these tests were performed, and it is assumed that no second-order wave steering was applied. Waves were measured at a location 20 m from the wave board where the bed level was still horizontal. The sand had a diameter of $D_{50}$ = 220 µm.

The model test 2E, also described in \citet{Arcilla1994}, concerns extreme conditions with a raised water level at 4.6 m above the flume bottom, a significant wave height, $H_{m0}$, of 1.4 m (corresponding to some 7 m on prototype scale) and peak period, $T_p$, of 5 s (corresponds to 11 s on prototype scale). During the test substantial dune erosion took place.

Based on the integral wave parameters $H_{m0}$ and $T_p$ and a standard Jonswap spectral shape, time series of wave energy were generated and imposed as boundary condition. Since the flume tests were carried out with first-order wave generation (no imposed super-harmonics and sub-harmonics), the hindcast runs were carried out with the incoming, bound long waves set to zero as well. Active wave reflection compensation (ARC) was applied in the physical model, which has a result similar to the weakly reflective boundary condition in XBeach, namely to prevent re-reflecting of outgoing waves at the wave paddle (offshore boundary).


The comparison between the observed profiles and computed profiles is shown in \autoref{fig:lip_2E} and the results for the indicators are shown in \autoref{tab:DeltaflumeLIP11D_2E_indicator}. The relative errors from \autoref{tab:DeltaflumeLIP11D_2E_indicator} are also shown in \autoref{fig:2E_BOI_errorTime}.

${tools.image('DeltaflumeLIP11D/2E/', '2E_BOI_profiles.eps', 'Comparisons of profiles from experiment LIP 2E for different moments in time. Observed profiles are shown with a dashed line and the XBeach profiles with a solid line. The storm surge level is shown with a black dashed line.','lip_2E',width=150)}
${tools.table('DeltaflumeLIP11D/2E/', 'indicator.tex', 'Indicators for 2E',small=True)}
${tools.image('DeltaflumeLIP11D/2E/', '2E_BOI_errorTime.eps', 'Temporal development of the relative error for the three indicators.',width=100,label='2E_BOI_errorTime')}




