Historical Evolution and Morphological Analysis of "EI Puntal" Spit, Santander (Spain)

Abstract

The historical evolution of'EI PuntaI' Spit in Santander, Spain, is herein presented. Field measurements of tides, currents and bathymetric profiles carried out to design a new navigation channel for the harbor of Santander, are used to explain the morphodynamics of the tidal channel and the spit. The Empirical Orthogonal Function (EOF) method is applied to analyze the longshore changes of the spit caused by storm and tide activities. Results of the EOF analysis show that the spit can be divided into a tide dominated section and a storm dominated section. The intertidal shoreface slope of these sections shows a distinct pattern of behavior under storm conditions: while the tidal sections accreties, the storm sections erode; during wave calm periods the opposite occurs. Dredging activity in the navigation channel (tide section) during the last fifty years has led to an overall non-equilibrium of the spit.