Estudo das tendencias granulometricas na praia de Costa do Sol

Abstract

The Costa de Sol beach, receives sediments from Maputo Bay that is constituted by sandbanks brought by the rivers that flow in the Bay. The beach has been suffering several environmental impacts that stand out the erosion caused by the lack of sediments, the sea protection work (Spurs) that influence in the sedimentary dynamic. For the efetivation of the study, they were collected 10 samples, ½kg for each sample where the carbonate fraction and the organic matter were removed and were continued with the processing laboratorial sift. The carbonate fraction is of biological origin and it presents a maximum variation of 32.82% and minimum of 1.57%. The organic matter, that it is of terrestrial origin, it changes from 45.59% to 2.61% along the beach. The sorting of sediments changes from moderately sorted and badly sorted; the asymmetry is predominantly positive because it presents many fine sediments; the curtose is leptokurtic. The granulometric parameters change along the beach and they affect the longitudinal transport direction that happens at the two senses northeast and southwest, influencing the erosion and deposition.