Barrier islands are important features in the coastal zone, among others because they shelter the mainland from waves and storm surge. Thus, the degradation of barrier islands can pose a threat to coastal safety. Hence, there is a societal demand for understanding and predicting barrier island evolution. High energy events, such as storms and hurricanes, play an important part in this evolution, with hydraulic sediment transport causing large and rapid changes in morphology. In the periods between storms, (partial) barrier island recovery takes place, largely driven by aeolian sediment transport on longer timescales. Hence, when predicting the morphological development of barrier islands, both hydraulic and aeolian transport need to be taken into account. Also, both the event timescale of hours to days, and the recovery timescale of weeks to months need to be resolved. Currently, no single numerical model exists that simulates both hydraulic and aeolian transport, though there are models that resolve either one separately. So, to resolve both simultaneously, two models will have to be coupled. The above leads to the two objectives of this thesis; firstly, constructing a coupling between a hydraulic and an aeolian sediment transport model, and analyze physical and numerical aspects of the model interaction. For this purpose the models XBeach and Dune are selected. The coupling is created using the Earth System Modelling Framework (ESMF). The second objective is confirmation of the predictive skill of the coupled model for the evolution of a real barrier island. Assateague Island (MD, USA) is selected, and a combination of model skill score and bias is used to represent the predictive capabilities of the coupled model. From a process point of view, undertow, long wave flow, and increased turbulence due to wave breaking have a significant effect on the sediment transport during storms, and all are represented within the XBeach model. Aeolian transport is less important during storms, because the sand supply is limited by submergence and moisture content. During recovery, aeolian transport does play an important role in transporting the sediment towards the beach and dunes, where it is often trapped by vegetation. The lower wave height during these periods allows for a relatively larger influence of short wave asymmetry, that can lead to hydraulic transport towards the shoreline, creating a sediment supply for beach and dune recovery. This makes the foreshore zone an interface between hydraulic and aeolian processes. The coupling between XBeach and Dune allows the models to exchange information after every communal timestep, thus facilitating dynamic interaction. This is only necessary when simulating recovery periods, for the influence of aeolian transport during storms is assumed negligible. The structure of the ESMF makes it possible to couple multiple models together, requiring only a few adaptations to the structure of the sub-model codes. This also provides the flexibility to add new or replace old models with relative ease. To confirm the predictive skill of this coupled model, a hindcast of six months of morphological development of Assateague Island will be performed. To this end, storms are distinguished from recovery periods, and are simulated in chronological order, the former with XBeach, the latter with the coupled model. The simulations lead to negative skill scores because of a significant overestimation of storm induced erosion. Even when using an overwash sediment transport limiter to reduce the erosion during storms, the skill scores remain negative. It can be concluded that the first objective has been fulfilled, since a coupling between XBeach and Dune has been constructed. Although a hindcast was performed, this could not confirm the predictive skill of the coupled model, so the second objective was not completed.