Use of multitracers for the study of water mixing in the Paraíba do Sul River estuary
| Autor: | Zenildo L. Carvalho, José Marcus Godoy, Maria Luiza D.P. Godoy, Carlos Eduardo de Rezende, M. S. M. B. Salomão, Thaísa Abreu Souza, Isabel Moreira |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Wet season
Salinity Silicon Rain Health Toxicology and Mutagenesis chemistry.chemical_element Radium Rivers Dry season Water Movements Environmental Chemistry Seawater Water Pollutants Waste Management and Disposal Hydrology geography Radionuclide geography.geographical_feature_category Geography Pelagic zone Estuary General Medicine Pollution Plume chemistry Barium Uranium Environmental science Seasons Brazil Environmental Monitoring |
| Zdroj: | Journal of Environmental Radioactivity. 101:564-570 |
| ISSN: | 0265-931X |
| DOI: | 10.1016/j.jenvrad.2009.11.001 |
| Popis: | Multitracers were used to study water mixing in the Paraiba do Sul River estuary region in August 2007 (dry season) and March 2008 (rainy season) and to evaluate the reach of the river plume in the direction of the open ocean. Two sampling campaigns were carried out, each in a different season. Based on these results, it was possible to conclude that the multitracers used in this study (salinity, Si, Ba and U, as well as the radium isotopes 223 Ra, 224 Ra, 226 Ra and 228 Ra) presented satisfactory results toward defining the plume reach and determining the residence time and water-mixing processes in the estuary. A strong correlation was observed between tracers and the distance to the coast. During the low river water discharge period, the riverine water took about 10 days to reach open ocean waters (salinity - 35). During the rainy period this value decreased to 6 days. Based on the radium results, it was possible to calculate diffusion coefficients (K h ) of23 km 2 d ―1 and 38 km 2 d ―1 for 224 Ra and 223 Ra, respectively, during the dry season (winter). Values of 65 km 2 d ―1 and 68 km 2 d ―1 for 223 Ra and 224 Ra, respectively, were found for the rainy period (summer). |
| Databáze: | OpenAIRE |
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