Statistical analysis results supporting "Evaluation of seagrass as a nature-based solution for coastal protection in the German Wadden Sea under end-of-century sea level rise projections" (DOI: 10.1007/s10236-026-01784-w)

Overview This dataset contains the statistically processed outputs of hydrodynamic model simulations assessing seagrass as a nature-based solution (NbS) for coastal protection in the German Wadden Sea under projected end-of-century sea level rise. The analyses are derived from the publication Jacob et al. (2026, accepted for publication in Ocean Dynamics) and support the figures, tables, and conclusions presented therein. The simulations were conducted using the SCHISM v5.11.0 unstructured-grid hydrodynamic model, which includes wave dynamics, sediment transport, and a first-order seagrass vegetation module. Simulations were performed for the years 1997 and 2090 under the RCP8.5 scenario. Pairwise simulations were executed with and without seagrass, enabling quantification of vegetation-induced attenuation of hydrodynamic forces. Data Contents Files included: annual_statistics_veg_MAX_1997.nc annual_statistics_veg_CNTRL_1997.nc annual_statistics_veg_MAX_2090.nc annual_statistics_veg_CNTRL_2090.nc These NetCDF files contain annual mean and 95th percentile statistics of key hydrodynamic variables derived from hourly-resolved SCHISM outputs. Variables include: Variable Description Units zos_mean Mean sea surface height (SSH) m zos_quantile95 95th percentile SSH m speed_bar_mean Depth-averaged sea water velocity magnitude (mean) m/s u_bar_mean, v_bar_mean Depth-averaged eastward and northward velocity (mean) m/s speed_bar_quantile95, u_bar_quantile95, v_bar_quantile95 95th percentile velocities m/s swh_mean, swh_quantile95 Significant wave height (mean and 95th percentile) m tau_b_mean, tau_b_quantile95 Bottom stress magnitude (mean and 95th percentile) Pa tau_bx_mean, tau_bx_quantile95 Eastward bottom stress Pa tau_by_mean, tau_by_quantile95 Northward bottom stress Pa tsl_mean, tsl_quantile95_bottom Total suspended sediment concentration (mean and 95th percentile) g/L All variables are defined on the SCHISM unstructured grid with UTM zone 32N (EPSG:32632) coordinates. Dry periods were masked to avoid skewed statistics. Mesh / Grid Description (UGRID): The dataset uses an unstructured triangular mesh defined on the SCHISM hydrodynamic model grid. Mesh topology: 2D, with node coordinates (SCHISM_hgrid_node_x, SCHISM_hgrid_node_y) and triangular face connectivity (SCHISM_hgrid_face_nodes). All hydrodynamic variables are defined at nodes. Coordinates are in UTM Zone 32N (EPSG:32632), consistent with the German Wadden Sea domain. Methodological Summary Simulation Framework: SCHISM v5.11.0, unstructured-grid hydrodynamic model with coupled wave, sediment, and vegetation modules. Analysis Periods: 1997 (baseline) and 2090 (future, RCP8.5). Vegetation Scenarios: MAX (with seagrass) and CNTRL (without seagrass). Statistics: Annual mean and 95th percentile computed from hourly model outputs using Python’s xarray library. Analysis Focus: Quantification of seagrass-induced attenuation of currents, wave energy, bottom stress, and sediment concentration. Absolute and relative differences between scenarios were calculated. Spatial Analysis: Depth-binned averages (0.4 m bins relative to present-day bathymetry) used to examine attenuation as a function of water depth.