Erosion Negril Beach

Abstract

The ongoing erosion of the Negril Beach has become worse the past decade. In most places along the coast line, the beach will be gone in approximately 10 years. This will result in a major decrease of incomes that are made by the local tourist sector. To prevent the erosion this study has been performed to find a feasible and affordable solution. An important part of the study is the literature research since several other parties had investigated different aspects of the erosion problem recently. Before any solutions can be brought up different aspects have to be investigated. These are a clear view of the actual problem, a good knowledge of the environment, profiles of the coastline, current patterns and sea grass locations to avoid environmental damage as much as possible. Data was collected during two field trips to Negril in the end of 2006. After collecting this data an analysis was made using different computer models as LITPACK (sediment transport), SWAN (waves) and RMA (currents). The data analysis shows that the primary concern is the erosion at Long Bay since the erosion in Bloody Bay is not that severe. Possible solutions are generated and their validity has been checked. Five alternatives can be distinguished: zero-alternative, nourishment, series of near-shore breakwaters, off shore reef extension and a combination of all. Using a Multi Criteria Analyses (MCA), that ranks solutions by their desired effects (without including costs), objectively the 'best' solution is found. The solution that scores best at our criteria is beach nourishment along Long Bay. When costs are taken into account, this solution seems to be the most efficient. Costs are estimated US$7,000,000. The final recommendation is to execute beach nourishment only at Long Bay. This solution is relatively affordable and shows the highest score in the MCA. The implementation of this solution results in a minimum beach width of about 10 meters for 20 years, about 30 meters in the year of execution. According to local divers the required sand can be found 2km offshore at the beginning of the outer shell. Beside of that it is recommended to perform a separate investigation concerning the water quality to deal with the algae contamination.Hydraulic EngineeringCivil Engineering and Geoscience