Recent evolution of the river mouth intertidal zone at the Río San Pedro tidal channel (Cádiz Bay, SW Spain): controlling factors of geomorphologic and depositional changes
- Autores: José Manuel Gutiérrez Mas, Santiago García López
- Localización: Geologica acta: an international earth science journal, ISSN 1695-6133, Vol. 13, Nº. Extra 2, 2015 (Ejemplar dedicado a: Special Issue: Selected contributions from the 7th Iberian Conference on Coastal Geomorphology.), págs. 123-136
- Idioma: inglés
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Resumen
Sedimentary and photogrammetric analysis of a sector of Cádiz Bay (SW Spain), including the intertidal zone onthe left bank of the Río San Pedro tidal channel, were performed to understand its environmental evolution andthe main factors that controled it. The study of this especially vulnerable environment has allowed to establishits depositional and morphological responses to the dynamic processes caused by recent environmental orclimate changes. In the bank of the Río San Pedro tidal channel, there is a well-developed saltmarsh, whichalternates with sandy beaches the data indicate erosional processes. The saltmarsh retreat rate was estimated in0.65m/yr from 1977 to 2008. In this time-period, the tidal channel experienced a lateral displacement towardthe SE of 1.24m/yr, and the beach width decreased from 50 to 21m. Three evolutionary stages were established:a youth stage, represented by a relatively high water energy beach environments; a maturity stage: representedby saltmarsh with deposition of mud and halophyte vegetation; a reactivation stage: represented by erosivefeatures in the saltmarsh, such as tidal pools, tidal channel, etc. The geological location of Cádiz, close tothe Eurasian–African plate boundary, account for its relatively high seismic and tsunami activity, that causedsignificant depositional changes in the area. Others important factors controlling the sedimentation are: firstthe tides, followed by the waves and the proximity to a sand source, such as the sandy mantle of La Algaida.
