Abstract
Sand beaches and spits of the southern embankment of the inner Tagus estuary indicate the influence of locally generated wind waves. The aim of this study is to evaluate the ability of these waves to resuspend bottom sediments, and sustain the longshore transport. For this purpose, local wave climates were obtained by running a wave forecasting numerical model for three selected target areas.
Results suggest that local wave climate is largely responsible for sand movement and accumulation in the marginal zones of the inner estuary facing the longest effective fetch. Two main areas of longshore transport were identified in the inner Tagus estuary with similar annual gross transport rates, of about 12 000 m3 yr−1. Results obtained for the annual net drift amount and direction are in agreement with geomorphology and accretion direction of the beaches. Wave-induced longshore transport rates agree with field observations and erosional evolution of the Alfeite sand beach during the last century.
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Freire, P., Andrade, C. Wind-induced sand transport in Tagus estuarine beaches – First results. Aquatic Ecology 33, 225–233 (1999). https://doi.org/10.1023/A:1009911012260
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DOI: https://doi.org/10.1023/A:1009911012260