Investigation of inhomogeneous wave conditions in Sulafjorden

Abstract

Complex fjord topography (bathymetry and coastline) may differentiate significantly wave conditions not only compared with the offshore ones but in the vicinity of few tens of meters. In the present work, possible inhomogeneities of wave conditions are investigated in a hypothetical bridge crossing in the area of Sulafjorden, central Norway. More specifically, wave conditions at ten positions across the bridge crossing have been derived by means of numerical modelling. The analysis has been carried out by transferring o shore wave conditions to the nearshore area by successive applications of the well–known third–generation wave model SWAN. As input, a very detailed bathymetry of the area, and time series of wind and wave parameters, derived from ERA5 database, have been used. At the target points, long–term time series of directional wave spectra have been used as input for the assessment of the inhomogeneity hypothesis. Various statistical features have been examined including, among others, the seasonal variability, the probability structure, the directionality, the correlation structure, and the long–term wave spectra.