Beach erosion is one of the leading problems that coastal regions face worldwide, and coastline evolution studies show how much it affects the coastal system. Usually these studies are site-specific and lack an integrated approach to either a large spatial domain or quantification using a single measurement. The first global Portuguese study on low-lying sandy beaches was developed with an integrated approach and provides an openly accessible database to support knowledge on the coastline evolution of Portuguese low-lying sandy coasts in the last 50 years (https://doi.pangaea.de/10.1594/PANGAEA.859136).
Results show erosion as the dominant trend (−0.24 m year−1), but sandy beach–dune systems display a variable evolution, both in signal and intensity, along and within the eight coastal sediment cells of the studied coast. The study identifies Espinho–Torreira, Costa Nova–Praia de Mira, Cova da Gala–Leirosa, and Cova do Vapor–Costa da Caparica coastal stretches as the most significant beach erosion issues found in the Portuguese coastline. These coastal segments adjacent coastal zone is linked with major human interventions, which interfered with the coastal system, and many of which originated and maintained a sediment deficit. In contrast, the coastal segments Troia–Sines and Sines–Cape S. Vicente have experienced less intervention and show stable or moderate accretion behaviour.
These results brings to light the importance of coastal change evaluation and quantification, but also the importance of understanding the underlying causes of such change, which is intertwined with sediment budgets and sediment practices taking place within the coastal zone and adjacent watersheds.
The study is freely available at http://www.earth-syst-sci-data.net/8/265/2016/ and further information can be obtained by contacting fclira@fc.ul.pt.
(Source: SedNet, http://sednet.org/)