Annual and Seasonal Variability of the Littoral Drift at Aveiro, Northwestern Coast of Portugal

Abstract

This work characterizes the littoral drift at Aveiro for the last 20 years (2000–2019). Aveiro is located on the Northwest coast of Portugal, fully exposed to the highly energetic wind-wave regime generated in the Northeast Atlantic Ocean. The induced longshore sediment transport (LST) rates affect coastal evolution, and its quantification is often required for many purposes regarding managing coastal zones. The annual and seasonal variability of the LST is estimated from some parameters of the wave climate by applying different empirical formulations. Different wave climate databases are considered in this analysis, namely, data from reanalysis and data from wave buoys. These data help validate the WAVEWATCH III model (WWIII) results, which are subsequently considered to estimate the LST. Computed annual LST values show substantial variability in response to the wave climate seasonality. The littoral drift has a preferential direction from north to south. Higher LST values are obtained in the winter months, which result from a balance between the positive N-S and negative S-N components, and lower in summer months, which are essentially determined by the positive component.