Data/hora: 06/06/2024 07:49:38

Provedor de dados: | 5
País: | France
Título: | Devenir de l'atrazine dans le bassin de Marennes-Oléron. Approche par la modélisation hydrodynamique, hydrosédimentaire et biogéochimique
Autores: | Vanhoutte Brunier, Alice.
Data: | 2001
Ano: | 2001
Palavras-chave: | Produits phytosanitaires; Atrazine; Cycle biogéochimique; Modélisation; Dynamique sédimentaire; Vasières intertidales; Pesticides; Atrazine; Biogeochemical cycle; Models; Sediment transport; Intertidal muflats.
Resumo: | Atrazine is the most widely used herbicide on cultured areas. This pesticide is degraded during its transport in rivers and streams, to the coastal area. Marennes Oléron is the main french oyster farming area, receiving the fresh water from the Charente river and ail the drainage coming from the coastal cultivated marshlands. Agriculture is thus claimed to be responsible for shellfish mortality in the aquaculture area. To simulate the changing fate of atrazine in the environment, a modelling strategy has been selected. a) First, using a two-way hydrodynamic model developped by IFREMER, the atrazine dilution trail in the Marennes Oléron area was simulated.Combined with larvae bioassays of Crassostrea gigas (Japanese oyster), the results show atrazine rates above 800 µg/l in the northern part of the area, inducing larval mortalities from 22 to 48%. a) A one way model perpendicular to the shore and incorporating far more processes than the preceding area was designed.Here, equations for sediment transport, diffusion and degradation in sediment were added to the advection model. Under simulations conditions, the modelled us to the conclusion that atrazine transfer fluxs in the sediment (deposit and diffusion) are low in comparaison with advective fluxs (in the order of 1/400th). The degradation represents 3% of the flux entering the sediment. These preliminary results could be improved by additions to the sediment part of the model and by including phenomena affecting water currents speed
Tipo: | Text
Idioma: | Francês

Identificador:

http://archimer.ifremer.fr/doc/00412/52312/53082.pdf

http://archimer.ifremer.fr/doc/00412/52312/

Formato: | application/pdf

Fonte:

2001 Ifremer, Université de La Rochelle

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