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De la mesure a la modelisation de transferts de produits phytosanitaires a l'echelle du bassin versant : quantification des incertitudes et definition de strategies d'echantillonnage

Abstract : Due to the frequent detection of pesticides in the surface water and groundwater, which constitute a threat to the quality of water masses in France, much attention has been paid to localizing the inputs, in order to target curative actions more efficiently. The catchment is a pertinent scale to manage the pollution and pesticides monitoring programs at the outlet of the catchment aim for the identification of the transfers of the pesticides and the reduction of the water pollution, especially in sensitive agricultural areas as Alsacian piedmont plain, whose groundwater is particularly threatened. But the strategy used to follow the evolution of the concentrations in pesticides conditions the representation which one has of the pollution and by there influence the effectiveness of the actions implemented to reduce this pollution. However, in an operational context, the low number of analyses is often required in priority, for economic reasons, with the detriment of the representativeness of measurements. We thus propose to answer the following question: can one define strategies of measurement of the concentrations in pesticides at the outlet of a small agricultural basin allowing a not skewed representation of the pollution of the surface water with little cost, i.e. with a minimum of analyses? We base ourselves on current knowledge on the dominant processes in the transfer of the pesticides to the outlet of small agricultural basins during a storm event and use two models of transfer, adapted to the quantity and quality of the available data for their parameterization, as well as the analysis of uncertainties of modeling, to define two strategies of sampling. The two strategies are adapted respectively to a global approach and a distributed approach of the system, and make it possible to reproduce a pollutograph of reference starting from the small number of measurements of concentrations proposed by our strategies: the models are used as interpolaters of the measurements. In the actual position, the method supposes perfect models and is not directly applicable to real pollutographs with the versions of models used. These strategies with operational aiming must thus be used with models having better qualities of interpolation. But the efforts of parameterization of these future versions will not have to be higher than the costs (money, time) authorized, in an operational context, for the follow-up of the evolution of the concentrations in pesticides itself. Currently these models do not exist and the lifting of this bolt constitutes one of the prospects for the result of the construction of operational strategies, that this study strongly contributed to prepare.
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https://pastel.archives-ouvertes.fr/pastel-00003803
Contributor : Ecole Agroparistech <>
Submitted on : Thursday, June 5, 2008 - 8:00:00 AM
Last modification on : Monday, October 19, 2020 - 11:07:49 AM
Long-term archiving on: : Friday, September 10, 2010 - 12:41:09 PM

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  • HAL Id : pastel-00003803, version 1

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Stéphanie Madier. De la mesure a la modelisation de transferts de produits phytosanitaires a l'echelle du bassin versant : quantification des incertitudes et definition de strategies d'echantillonnage. Sciences of the Universe [physics]. AgroParisTech, 2007. English. ⟨NNT : 2007AGPT0080⟩. ⟨pastel-00003803⟩

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