| Autor: |
Carole Sinfort, Anne Meillet, Bernard Panneton |
| Rok vydání: |
2011 |
| Předmět: |
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| Zdroj: |
2011 Louisville, Kentucky, August 7 - August 10, 2011. |
| DOI: |
10.13031/2013.37339 |
| Popis: |
The Gibault-Delisle watershed (19 km2) is located in the South-West region of the St Lawrence River, Quebec (Canada). It is mainly occupied by horticultural crops. A recent study revealed that the river was contaminated with pesticides all along the cropping season. Some concentration peaks were not linked to rain episodes and could not be imputed to the leaching of deposits on plants or ground. The objectives of this study were to evaluate if measured concentrations could result from drift during applications and to evaluate the potential of some mitigation measures. A spatio-temporal model was built from drift curves and a transport equation along the streams in the watershed. Model inputs were applied pesticides (depending on the crops), wind direction, size and position of the plot with respect to watercourses and water flowrates. Pesticide application records available from a farmer consortium were used to compute maximum hourly concentrations per week. Results for concentration in water from the model are of the same order of magnitude than measurements so drift could be a main contributor to river contamination. Improving sprayer setup to limit drift decreases concentrations by a factor of 10 while implementing systematic 5m buffer zones yielded a 30% reduction. Monte-Carlo simulations based on a probabilistic description of the input factors of the model was performed for a sensitivity analysis and showed that the river flowrate is the main factor influencing the results. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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