For reasons of computational efficiency, 1D XBeach cross-shore transect models are often applied on quasi alongshore-uniform coasts instead of a more computationally expensive 2DH modelling approach. In this paper we describe a practical methodology to allow 1D models to mimic infragravity wave growth observed in field conditions and represented in 2DH models and thereby significantly reduce the overestimation of infragravity wave heights near to the shore. We show that even if the coastal setting may support the 1D model assumption of alongshore uniformity in forcing and bathymetry, 1D XBeach models will overestimate infragravity wave growth relative to field conditions due to the underlying assumption of alongshore-uniform intra-wave (group) hydrodynamics common to all wave (group)-resolving models. Model analysis showed little variation in the optimum calibration value of this approach for a large range of wave forcing conditions (wave height, period and directional spread) and consistency with 2DH model results for a large range of Dutch coastal profiles. Comparison to field observations showed that the methodology significantly increased the skill of the 1D model to simulate nearshore IG wave heights. These results have implications on the ability to accurately predict the response of these coasts to energetic events, which is crucial to assess current and future flood risk and to design effective flood protection and mitigation measures.

A large-scale field campaign was carried out on the ebb-tidal delta (ETD) of Ameland Inlet, a basin of the Wadden Sea in the Netherlands, as well as on three transects along the Dutch lower shoreface. The data have been obtained over the years 2017-2018. The most intensive campaign at the ETD of Ameland Inlet was in September 2017. With this campaign, as part of KustGenese2.0 (Coastal Genesis 2.0) and SEAWAD, we aim to gain new knowledge on the processes driving sediment transport and benthic species distribution in such a dynamic environment. These new insights will ultimately help the development of optimal strategies to nourish the Dutch coastal zone in order to prevent coastal erosion and keep up with sea level rise. The dataset obtained from the field campaign consists of (i) single-and multi-beam bathymetry; (ii) pressure, water velocity, wave statistics, turbidity, conductivity, temperature, and bedform morphology on the shoal; (iii) pressure and velocity at six back-barrier locations; (iv) bed composition and macrobenthic species from box cores and vibrocores; (v) discharge measurements through the inlet; (vi) depth and velocity from X-band radar; and (vii) meteorological data. The combination of all these measurements at the same time makes this dataset unique and enables us to investigate the interactions between sediment transport, hydrodynamics, morphology and the benthic ecosystem in more detail. The data provide opportunities to calibrate numerical models to a high level of detail. Furthermore, the open-source datasets can be used for system comparison studies. The data are publicly available at 4TU Centre for Research Data at https://doi.org/10.4121/collection:seawad (Delft University of Technology et al., 2019) and https://doi.org/10.4121/collection:kustgenese2 (Rijkswaterstaat and Deltares, 2019). The datasets are published in netCDF format and follow conventions for CF (Climate and Forecast) metadata. The http://data.4tu.nl (last access: 11 November 2020) site provides keyword searching options and maps with the geographical position of the data.