BEACH RESTORATION IN THE TARRAGONA COAST (SPAIN); SAND MANAGEMENT DURING THE LAST 25 YEARS AND FUTURE PLANS

摘要

Erosion is the dominant behavior along worldwide coastlines. Although many factors can locally influence processes governing coastline evolution some common factors can be identified. Thus, the sediment budget has largely been modified in most of developed coasts, with river sand supplies being drastically reduced due to human influence in drainage basins. On the other hand, coastal segmentation due to infrastructures alters sediment transport patterns and induces and/or accelerates coastline erosion. Within this general context, artificial nourishment has been one of the most used coastal engineering measure by mimicking the role played by river sediment supplies to compensate local erosion problems. Since nourishment is not acting on the origin of the problems, erosive processes will continue to control shoreline evolution. Thus, the evolution of beach fills will be controlled by the sediment budget within the coastal cell where works have been done and, this will determine required sediment volumes to maintain the future shoreline. Within this context, we present data on long-term (25 years) shoreline evolution and nourishment operations in the Tarragona coast (Spain, NW Mediterranean). The main aim of the work is to analyze the coastal stability and the effects of beach fills along the coast taking into account the type of the coastal cell where works have been implemented. Once this has been evaluated, the sustainability of an adaptation strategy based on the use of this protection measure to cope with climate change induced scenarios is also assessed to propose a long- term sediment management plan.