Coastal dunes systems are important features of the coastal morphology, providing natural protection against storm impacts and serving as habitats for diverse species. Numerical models of coastal evolution are typically categorized by the temporal and spatial scales of the processes that they describe: cross-shore numerical models address sediment transport within the beach profile over short to medium timescales related to storm events (days to months); and shoreline evolution models simulate changes in coastal morphology due to longshore sediment transport processes over timescales ranging from years to decades. In this study, the numerical approach presented by Ferreira et al. [1, 2] was applied to evaluate the sediment dynamics and the morphological evolution of the berm-dune system in a coastal domain. This approach, developed to conduct medium to long-term time scales analyses with low computational effort, combines longshore and cross-shore sediment transport processes, by integrating the results of two numerical models (LTC and CS-Model). The results highlight the interconnections between cross-shore and longshore sediment transport processes and emphasize the importance of incorporating longshore effects into numerical modelling of beach-dune systems, from a medium to long-term perspective (years). Furthermore, the study demonstrates the potential of the model to support coastal management through its outputs (shoreline position, berm width, dune evolution and regenerative capacity due to windblown sand transport).