Work

Dynamique des marais d'arrière-barrière associée à la passe de Barra Nova (Ria Formosa, Portugal méridional) / Evolution of backbarrier salt marshes related to the Barra Nova inlet dynamics (Ria Formosa, south Portugal)

Year: 2003

Type: article

Abstract: Mapping of salt marsh habitats through time in the western part of the Ria Formosa mesotidal lagoon (south Portugal) highlights the morphological and botanical changes related to an inlet artificially cut through the barrier island system in 1997. Sand transport and deposition pattern within the backbarrier area appear to be linked to the reversal of tidal or wave-dominated conditions through the inlet in response to meteorological variability offshore. Results from two years of sediment monitoring have shown a surface lowering of all plots, particularly in the upper and mature marshes, although short periods of accretion were recorded in the lower Spartina marshes. This unusual pattern of sedimentation can be related both to the asymmetry typical of such shallow-water environments and to the long-term stability of the inlet location. It seems likely that the rate of salt marsh lowering will decline or even revert in the future as confinement of the marsh increases due to an eastward migration of the inlet.

Source: Géomorphologie relief processus environnement

DOI: 10.3406/morfo.2003.1176