Channel refraction, a process in which obliquely incident waves are turned by navigation channel slopes and effectively reflected away from the channel, can significantly influence nearshore hydrodynamics and sediment transport. This thesis investigates how well phase-averaged an
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Channel refraction, a process in which obliquely incident waves are turned by navigation channel slopes and effectively reflected away from the channel, can significantly influence nearshore hydrodynamics and sediment transport. This thesis investigates how well phase-averaged and phase-resolving numerical models capture these effects. A comparative study was conducted using SWAN-FINEL (phase-averaged) and XBeach non-hydrostatic (phase-resolving). First, model performance in simulating wave transformation was assessed using a physical model of Taman Port. Both models reproduced general wave patterns and showed comparable performance based on the wave measurements. XBeach offered slightly improved accuracy in energetic conditions and on the lee side of the channel. Second, an idealized numerical experiment was used to explore sediment transport differences. Offline sediment transport calculations using an intra-wave and phase-averaged model based on the Meyer-Peter-Müller formulations revealed very similar longshore transport gradients and infilling patterns, but notable differences in cross-shore transport due to the inclusion of wave skewness, asymmetry, and swash-zone processes in XBeach. The findings highlight that while SWAN-FINEL performs well in longshore-dominated systems at low computational cost, phase-resolving models offer added value for short-term cross-shore-dominated settings, albeit at higher computational demand. Model choice should therefore depend on the dominant transport direction and project scope.