Coral reefs are degrading at an alarming rate, affecting not only the precarious coral ecosystem but also human habitat. The combination of coral degradation, sea level rise and its exacerbated effect in the tropics, and the possible storm intensification increases the flood vulnerability of low-lying tropical islands. To protect reef fronted coasts against flooding, coral restoration is put forward as measure to increase coastal safety. This study addresses the effects and efficiency of coral restoration in four steps. First, a simple reef hydrodynamic model is formulated to identify important drivers of runup at a reef fronted beach, to be used as a quick scan tool before using more intensive process-based models. Next, 30.000 US reef profiles are classified to gain insight into the prevalence of different reef shapes. Four dominant reef profiles are then used in the subsequent modeling step, in which the hydrodynamics and flood vulnerability of different reef shapes are investigated using the XBeach process-based model. With the knowledge gained, the hydrodynamic effects and runup reduction potential of different restoration configurations at various reef morphologies can be assessed.

Colombia’s economy has been growing steady in the past decades, partly because of the increase in tourism. However, this tourism also has a downside. Hotels and restaurants are constructed one after another, preferably along the coast. This, combined with factors such as climate change and land subsidence and the fact that people tend to prefer living close to the coast, leads to a vulnerable and erosive coast, especially in the departments of La Guajira and Magdalena. Therefore, Project Colciencias was initiated by three local universities and two companies, a large scale study to improve and implement coastal projects in this area. Focus is on areas that experience critical erosion; erosion that puts local economy, environment and national heritage at risk (Oceanus, 2013). Ten objectives are formulated by the five different parties, e.g. characterization of the coast, development of pilot projects and socialisation of coastal projects.
The goal of this multidisciplinary research conducted by TU Delft students in cooperation with Oceanus International is to improve the Colciencias project by combining Dutch and Colombian expertise, technology, efficiency and theory. After analysing the political, cultural, social, hydraulic and environmental situation, and after consulting various stakeholders three research objectives were stated and elaborated.
The first goal is to create a framework to ensure a consistent and efficient implementation of the intended pilot projects. Not only does it cover the hydraulic aspects of a project, it also takes into account the socio-economic, environmental and legal factors. To support the part of the framework that comprehends the hydraulic analysis and the development of alternatives for coastal protection, a detailed document on numerical models is written. This is objective number two. Next to information on numerical models in general, the three main types of coastal models are discussed; coastline, regional - and local morphodynamic models. Eight specific models are then further highlighted, resulting in a decision tree that helps in choosing the best model for your specific engineering application. To test the framework, a case study was executed in one of the critical erosion zones, the village of Ciénaga. The framework was followed concisely to evaluate its effectiveness and efficiency. Among other things, a field trip was organised to carry out experiments and execute a survey to explore the socio-economic values of the region. Next to that, interviews were carried out with officials and local parties to obtain information on past projects and the local legal framework. From the case study it was concluded that the framework functions, but that it should be noted that the case study is only a test of the framework, and that much further research needs to be conducted for the actual design and implementation of the coastal plan for Ciénaga.
Lastly, our goal was to start a dialogue about the impact of integrated coastal zone management and coastal erosion problems. In practice this resulted in many interviews, a survey, attendance of local community meetings, presentations at the Universidad del Norte for stakeholders of the project and an informal gathering of students at the Universidad de Cartagena. Furthermore, the framework shall be distributed to possible stakeholders as well as an informative presentation along with an introductory movie.