The exploration of solution strategies for the mitigation of coastal erosion by applying the BwN design process

Abstract

Coastline regression is a significant threat to many coastal zones. Being able to mitigate the erosion while simultaneously improving nature development is something that is increasingly strived for in coastal projects. This report utilizes the building with nature philosophy to explore integrated solutions for a coastal erosion problem in Negril, Jamaica. Erosion of the coast is threatening the many hotels and resorts along the beach near Negril. The hotel owners and the local community are looking for a sustainable solution to the erosion problem. The building with nature approach starts with the system in mind, not the intervention. First the cause of coastal erosion is better understood. A combination of factors is responsible of which the intensification of storm events and degradation of the environment are two of the main causes. A reduction of the sediment production rates could also have led to increased coastal erosion. Due to the lack of data in this phase of the project, the exact reason cannot be identified. Therefore, both scenarios are considered. From there, different solution strategies are explored and alternatives are identified. The strategies range from environmental solutions to soft, hard and hybrid solutions. These designs are simulated to understand their effectiveness by relative comparison. Alternatives that do not work as intended are excluded. The evaluation of the remaining alternatives shows what the strengths and weaknesses are of the different solution strategies. A social evaluation method is also applied to assess the applicability of this type of evaluation method and gain a broader perspective on the alternatives. If restoration of the natural sediment production leads to large production rates and a large improvement in overall environmental quality, then this solution strategy could be very positive. Nourishment strategies work well from a social and technical point of view but less ecologically. The nourishment strategies can be improved by adding environmental improvements to the alternatives. A hybrid solution has the potential to provide a positive effect on the technical, ecological as well as social aspects of Long Bay. However, this depends on the applicability of Reef Balls in breakwater designs and the effectiveness of coral transplantation. The BwN approach ensures that a wide range of solutions is considered. The results give more insight in the cause of the coastal erosion and possible solution strategies for Negril. Using the knowledge gained in this thesis, more detailed alternatives can be obtained in the future.