Principal Component Analysis Applied to Geomorphologic Evolution

The study area comprises a sector of the main channel of the entrance to Bahía Blanca system harbour. El Toro channel, characterized by recurrent accumulation processes, had to be dredged periodically to maintain the nominal depth of 10 m. Detailed surveys of the reach are made regularly to check the navigation conditions. A set of survey charts made within two dredging operations and covering about 1 year was analysed by means of principal component analysis (PCA). The first principal component obtained from PCA describes the mean depth of the area, while the second principal component explains the morphological variations over time. From it, the accumulation periodicity can be detected, and, therefore, when dredging becomes necessary. Based on dynamics studies, a large transverse flood current component is observed which is attributed to a postulated helicoidal flow pattern responsible for the large sediment accumulation observed in the south-east of the El Toro channel