Data/hora: 01/06/2024 08:49:45

Provedor de dados: | 5
País: | France
Título: | Etude du fonctionnement hydrosédimentaire d'un écosystème lagunaire sur des échelles de temps multiples. Application au complexe lagunaire "étangs Palavasiens - étang de l'Or - canal du Rhône à Sète"
Autores: | Castaings, Jerome.
Data: | 2012-12-13
Ano: | 2012
Palavras-chave: | Dynamique sédimentaire; Géochronologie; Hydrodynamique; Échelles temporelles; Lagunes; Sediment dynamic; Geochronology; Hydrodynamic; Time scales; Lagoons.
Resumo: | The sedimentary evolution of coastal lagoons is a complex phenomenon involving both short term extreme processes (floods, storms) and long term processes (mean sea level variations, climate change). If general mechanisms of these phenomena are well known, their spatial and temporal variability makes them difficult to assess at the local scale. The diversity of lagoonal environments and human influence makes this even more risky. I have focussed this study on the case of a Mediterranean lagoon system : “Palavasian lagoons, Or lagoon, and Rhône-Sète waterway” which is located in the Gulf of Lion (South of France). A ultidisciplinary approach was used to assess sediment dynamics on multiple time scales. An average filling rate of 1.3 mm.year-1 over the two last centuries was assessed using a both historical maps and geochronology (210Pb, 137Cs). An area loss due for half to anthropogenic impacts was also highlighted in the twentieth century. A short term (2 years) and high frequency monitoring of in situ hydro-sedimentary dynamics was performed to determine the influence of physical forcing over internal processes (erosion, resuspension, deposition). The main characteristics thresholds were estimated and related to weather conditions. The observed net balance during this monitoring shows a loss of sediment. This assessment, opposite of historical trends, is probably related to the conditions of reduced river contribution. The implementation of a numerical model is going on in order to explain the dynamics on a larger spatial and temporal scales
Tipo: | Text
Idioma: | Francês
Identificador: | http://archimer.ifremer.fr/doc/00193/30436/28853.pdf
Editor: | Université de Montpellier II
Relação: | http://archimer.ifremer.fr/doc/00193/30436/
Formato: | application/pdf
Fonte: | 2012 Univ Montpellier