A hydrological modeling framework for defining achievable performance standards for pesticides.
This paper proposes a hydrological modeling framework to define achievable performance standards (APSs) for pesticides that could be attained after implementation of recommended management actions, agricultural practices, and available technologies (i.e., beneficial management practices [BMPs]). An integrated hydrological modeling system, Gestion Intégrée des Bassins versants à l'aide d'un Système Informatisé, was used to quantify APSs for six Canadian watersheds for eight pesticides: atrazine, carbofuran, dicamba, glyphosate, MCPB, MCPA, metolachlor, and 2,4-D. Outputs from simulation runs to predict pesticide concentration under current conditions and in response to implementation of two types of beneficial management practices (reduced pesticide application rate and 1- to 10-m-wide edge-of-field and/or riparian buffer strips, implemented singly or in combination) showed that APS values for scenarios with BMPs were less than those for current conditions. Moreover, APS values at the outlet of watersheds were usually less than ecological thresholds of good condition, when available. Upstream river reaches were at greater risk of having concentrations above a given ecological thresholds because of limited stream flows and overland loads of pesticides. Our integrated approach of "hydrological modeling-APS estimation-ecotoxicological significance" provides the most effective interpretation possible, for management and education purposes, of the potential biological impact of predicted pesticide concentrations in rivers.
Institut National de la Recherche Scientifique-Centre Eau, Terre et Environnement, Québec, Canada. alain.rousseau@ete.inrs.ca
Alain N
AN
Rousseau
Pierre
P
Lafrance
Martin-Pierre
MP
Lavigne
Stéphane
S
Savary
Brou
B
Konan
Renaud
R
Quilbé
Paul
P
Jiapizian
Mohamed
M
Amrani
D002170:Canada; D003198:Computer Simulation; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods / Q000592:standards*; D008962:Models, Theoretical; D010575:Pesticides / Q000737:chemistry*; D013997:Time Factors; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014877:Water Pollution, Chemical / Q000517:prevention & control*
D010575:Pesticides; D014874:Water Pollutants, Chemical