This report presents a design study focused on a floating offshore barrier for catching sargassum to protect the coastline of the Yucatan region in Mexico. The research was conducted as part of the multidisciplinary course offered by the Civil Engineering faculty. The study involved five students from diverse disciplines: two hydraulic offshore students, one hydraulic engineering student, one structural engineering student, and one chemical engineering student.

Previous studies show that climate change effects and anthropogenic disturbances are having an increasingly strenuous effect on the performance of the coastal system of Sisal, a rural fishing village in the state of Yucatán, Mexico. Resilience has been a crucial component for these studies, as it presents the system's ability to react and adapt to environmental hazards and human interventions. In recent years, several research initiatives have aimed to assess the resilience of Sisal's coastal system through the use of previously identified resilience index calculations. However, these indices lack the ability to quantify disparities of resilience on a local scale. Furthermore, previous studies focus solely on the technical aspects of resilience, and therefore fall short on defining other relevant aspects of the term.

Consequently, this research project aimed to understand Sisal's coastline by understanding the multi-faceted definitions of resilience by analysing the socio-economic and technical factors impacting the coastal system. The study involved examining both its historical context, as well as potential future trends and developments.

This was done through a thorough evaluation of different aspects of the coast, a storm impact study and a social analysis. The findings of these studies are subsequently incorporated into a comprehensive web-tool, providing experts, policymakers, and community members with clear-cut and valuable information on the current resilience of Sisal's coastline.

The findings of the research present that the coastal resilience of Sisal is highly negatively impacted by human interventions along the coast, predominantly causing inadequate resilience performances on profiles with significant anthropogenic perturbations and generally along the coastline westwards of Sisal's port. Current coastal management policies are considered ineffective to deal with these developments, which is among others caused by exclusive decision-making processes and ambiguous governmental policies. Changes in coastal management strategies are therefore needed to effectively deal with future threats of environmental hazards and human interference. Ultimately, resulting in improved coastal and community resilience.

In 1990 the Dutch government passed legislation that dictates the South West Texel coast must be maintained with regard to the 1990 coastline. The coast is currently maintained by applying shoreface and beach nourishments with an interval of approximately 3 years, because it experiences erosion. The problems with this approach are that the mobilization of the dredging vessels is expensive, dredging vessels cause nuisance in the ecological system and moreover, the dredging vessels emit carbon dioxide and therefore contribute to climate change. The first goal of this study was to to investigate if an alternative coastal protection strategy is able to mitigate the drawbacks of the current scheme. Consequently, the application of a mega nourishment was chosen over a cross-shore dam or an outer delta nourishment. To optimally design a mega nourishment, a morphological analysis was executed that focused on elements in the sediment balance of the system. Using Vaklodingen and JARKUS data, volume changes of each transect were identified for 4 parts of the transect: the dune, the beach, the shallow part of the foreshore and the Molengat channel. It was found that dunes started growing from the moment that the nourishments were structurally applied. When nourishments are aborted, it is expected that the shrinking of the dunes will resume, just like the pre-1990 situation. The Molengat in the transects was found to be moving towards shore before the nourishment program started, and its landward movement was not influenced by the implementation of the nourishment program. The Molengat filling rate was projected into the future, leading to a fill date in transects 880-930 by 2035, and in transects 930-1013 by 2055. In transects 1013-1108 and 1108-1210 the Molengat has already been filled. The late projection filling date of transects 930-1013 is a reason to put the mega nourishment at that location, combined with the largest natural erosion occurring at the same location. The application of a mega nourishment is done by putting 20 years worth of sediment at transect range 945-1053 in one construction project. Simultaneously, the mega nourishment aims to diffuse sediment alongshore in the shallow part of the transects, providing sediment to adjacent transects. The sediment supply to other transects could be able to limit the shrinking of the adjacent dunes, or even let them grow. However, this requires further investigation. Delft3D Model results showed that sediment transport in this area is mainly caused by waves on the NUN-shoal, and by the current in the Molengat ebb-tidal channel. The model resolution was not fine enough to accurately describe the accretion and erosion patterns alongshore. Yet, by the use of results of morphological updates it could be determined that the mega nourishment will likely cause accretion south of the nourishment area. This research can be used as a stepping stone for future design steps of a mega nourishment, and also for acquiring knowledge about future behaviour of different parts of the bottom profiles in the South West Texel area.