VIII Jornadas de Geomorfología Litoral Geo-temas 15 ISSN 1576-517273 Análisis de los cambios geomorfológicos ocurridos en la flecha de Los Alfaques (Delta del Ebro, Tarragona)
- I. Rodríguez-Santalla 1
- F.Javier Gracia 2
- C. Pérez-Morales 1
- J. Serra 3
- A. Medialdea 4
- F. Barrio 1
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1
Universidad Rey Juan Carlos
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2
Universidad de Cádiz
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3
Universitat de Barcelona
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4
Technical University of Denmark
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ISSN: 1576-5172
Argitalpen urtea: 2015
Zenbakien izenburua: VIII Jornadas de Geomorfología Litoral
Zenbakia: 15
Orrialdeak: 73-76
Mota: Artikulua
Beste argitalpen batzuk: Geotemas (Madrid)
Laburpena
Los Alfaques spit, located south of the Ebro river mouth, is a sandy formation developed by the joining of littoral bars, which are oriented and modeled by waves coming from the East. The greatest development of the Ebro Delta took place in the 14th and 15th centuries, due to intense deforestation in the river basin, which led to the formation of both El Fangar spit (Nort) and Los Alfaques spit (South). Los Alfaques spit includes the remains of several historical beach ridges that suggest the delta evolution in the last centuries. OSL dating suggests that the first ridge was originated about 1700 A.D. This finding is coherent with different evolutionary studies previously made by other authors from cartographic reconstructions, and also from high resolution seismic geophysical data.The comparison of geomorphological maps derived from aerial photographs taken along the last 50 years, show how the initial ridges run parallel to the coast. Above them small dune developed, with their crests oriented parallel to the dominant wind. At the time the ridges were abandoned by shoreface progradation, due to the joining of new bars, the dunes were colonized by vegetation, resulting in the present foredune surrounding the delta wetlands.