Coastal erosion. Geometric detached breakwaters indicators for preventing the shoreline erosion. Fringe session

Abstract

The coastline today is undoubtedly in a precarious situation. Many beaches are suffering from erosion and the obvious environmental and landscape degradation of many coastal stretches are problems. Coastal Engineers are spending time in solving. With this in mind, different protection methods have been used over time, most based on the artificial nourishment of beaches and on building structures such as groynes and detached breakwaters. Detached breakwaters are artificial structures, generally parallel to the coastline, inspired on the working of natural formations, protecting a certain stretch from wave action and being able to create accretion areas. This is why these structures have been in general use with different results, since the 1970s, in countries such as Japan, the USA, Israel, Spain, Italy and Australia. The study undertaken for this research centres precisely on this type of structure, with the purpose of providing an overall view of the state-of-the-art in this field and a conceptual model for preventing the coastal erosion. In addition, the effects of a detached breakwater on the shoreline for a series of prototypes on the Spanish coastline and whether the empirical relations given by different researchers for classifying the shoreline’s type of response were fulfilled for them all or not, were researched. There sult of this work showed how sensitive the shore’s response is in relation to the non-dimensional B/X monomial (where B is the length of the detached breakwater and X its distance to the initial coastline) and the range of figures proposed for classifying the shore’s response based on that monomial.