Case study Piçarras Beach: Erosion and nourishment of a headland bay beach

Master project report. Piçarras is one of the touristic beaches of Santa Catarina state in Brazil. Piçarras beach is a headland bay beach. In the bay irregular features like an island, rocky outcrops and shoals are present influencing wave propagation. In the south Piçarras is bounded by Piçarras river. The river mouth has been fixated in 1970, after which erosion started. The part just a few hundred meters north of the river jetty has the most severe erosion. The erosion gradually decreases towards the north, where even some accretion has been measured. When the situation became critical a nourishment was executed in 1999, which has disappeared totally on some places. The decrease in beach width causes a devaluation of the houses and a decrease in tourism which consequently leads to a decrease of employment. It is therefore necessary to investigate the causes and the amount of the erosion and to generate measures to counteract the negative impact of the erosion. Prosul, a Brazilian engineering company, has designed a nourishment of which execution started in July 2008. The main goal of this study is investigate erosion at Piçarras beach and to design a nourishment to counteract the effects of the current erosion. A model has been built to represent the situation at Piçarras beach. With the model the evolution of the nourishment and the evolution of the existing plan of Prosul could be evaluated. The bathymetry has been composed of recent profile measurements and old nautical maps. They have all been related to the reference level of IBGE. To investigate the erosion at Piçarras beach the wave climate has been schematised. The available wave data was given for four direction (NE, E, SE, S) in the form of wave heights and periods. To be able to compare what the results of the incoming wave energy from these four directions were on the erosion and accretion on the beach, a schematisation has been made. A representative average wave per direction has been determined, th
Hydraulic Engineering
Civil Engineering and Geosciences