Efectes de la dinàmica sedimentària, l’activitat antròpica i l’ascens del nivell de mar a la platja de Sant Pere Pescador

Abstract

The beach of Sant Pere Pescador is in the Alt Empordà region and is the longest unit in the Gulf of Roses. As it happens to the rest of the Catalan coast, it is a part of the territory from which humans extract a great benefit. In this beach dominates the tourist use, recreational, nautical activities, and sports. This final degree project looks at the effects of sedimentary dynamics, anthropic activity and the rise in sea level. In order to do so, the current state of the beach is determined by aerial photographs and topographic profiles, the characteristics of the sediment by granulometric analysis by sieving, the vegetation cover and the state of the dune system are evaluated, the evolution of the coastline and the sedimentary balance. The areas of the beach with different characteristics are also individualized between the north sector, the central sector, and the south sector. It is observed how the adjacent areas on the beach have been anthropized, for crops and campsites, and how natural morphologies are minority. In addition, most dune forms are under training. On the other hand, the characteristics of the beach have a gradient from the northern sector to the southern sector due to: the wind incidence, the contribution of sediments and the evolutionary rate of the coastline. The central sector is an interface zone. Regarding the sedimentary dynamics, this has been modified anthropically by the construction of the Darnius-Boadella reservoir in the Muga and by the modification of the meanders of the Fluvià river. In addition, the sedimentary balance is negative and the volume of sediments available to the beach has been reduced, increasing its vulnerability for the future. In spite of this, for now, the vulnerability of the dunar system is medium-low. As for the coastline, it has regressed in recent decades but only 13.21% of the decline it has suffered is due to the rise in sea level. The other 86.79% is the cause of coastal drift and sedimentary dynamics modified by anthropic activity. Therefore, anthropic activity is the one that generates the greatest effects on the beach and has modified the sedimentary dynamics. On the other hand, the rise in sea level, that is the consequence of climate change produced by humans, affects the beach to a lesser extent