Sensitivity of a one-line longshore shoreline change model to the mean wave direction

The sensitivity of a one-line longshore shoreline change model to the incident wave direction is evaluated at Narrabeen Beach (Australia). As previously observed, application using conditions generated along 10-m depth contour produces long-term reorientation coastline, with an initial transition period and then new stable equilibrium during 10-year from 2005 2015. However, this coastline in planform shape not observed position measurements. source error investigated by assuming that it caused biases Monte Carlo approach search for optimal set angle bias corrections apply each cross-shore transect. obtained values enable reproduce accurately planform, they are coherent estimates breaking independently nearshore propagation model. Then, corrected time series as reference, second analysis completed investigate errors mean drawn Gaussian distributions varying standard deviations. shows range expected estimated beach. This work highlights importance considering simulations angle, which can be relatively large given uncertainties spectral direction, buoy observations, methods or input bathymetry used estimate conditions.