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TitreGroundwater nitrate concentration evolution under climate change and agricultural adaptation scenarios: Prince Edward Island, Canada
AuteurVigneault, H; Paradis, D; Lefebvre, R; Savard, M M; Ballard, J M; Quian, B
SourceEarth System Dynamics vol. 7, 2016 p. 183-202, https://doi.org/10.5194/esd-7-183-2016 (Accès ouvert)
Année2016
Séries alt.Secteur des sciences de la Terre, Contribution externe 20150425
ÉditeurCopernicus GmbH
Documentpublication en série
Lang.anglais
DOIhttps://doi.org/10.5194/esd-7-183-2016
Mediapapier; en ligne; numérique
Formatspdf
ProvinceÎle-du-Prince-Édouard
Lat/Long OENS -64.5000 -62.0000 47.2500 46.0000
Sujetseau souterraine; établissement de modèles; nitrate; analyses de l'eau; géochimie de l'eau; qualité de l'eau; écoulement de la nappe d'eau souterraine; simulations par ordinateur; azote; essais de perméabilité; changement climatique; Économie et industrie; Nature et environnement
Illustrationslocation maps; tables; schematic diagrams
Diffusé2016 03 09
Résumé(disponible en anglais seulement)
Nitrate (N-NO3) concentration in groundwater, the sole source of potable water in Prince Edward Island (PEI, Canada), currently exceeds the 10 mg L-1 (N-NO3) health threshold for drinking water in 6 % of domestic wells. Increasing climatic and socio-economic pressures on PEI agriculture may further deteriorate groundwater quality. This study assesses how groundwater nitrate concentration could evolve due to the forecasted climate change and its related potential changes in agricultural practices. For this purpose, a tridimensional numerical groundwater flow and mass transport model was developed for the aquifer system of the entire Island (5660 km2). A number of different groundwater flow and mass transport simulations were made to evaluate the potential impact of the projected climate change and agricultural adaptation. According to the simulations for year 2050, N-NO3 concentration would increase due to two main causes: (1) the progressive attainment of steady-state conditions related to present-day nitrogen loadings, and (2) the increase in nitrogen loadings due to changes in agricultural practices provoked by future climatic conditions. The combined effects of equilibration with loadings, climate and agricultural adaptation would lead to a 25 to 32 % increase in N-NO3 concentration over the Island aquifer system. The change in groundwater recharge regime induced by climate change (with current agricultural practices) would only contribute 0 to 6 % of that increase for the various climate scenarios. Moreover, simulated trends in groundwater N-NO3 concentration suggest that an increased number of domestic wells (more than doubling) would exceed the nitrate drinking water criteria. This study underlines the need to develop and apply better agricultural management practices to ensure sustainability of long-term groundwater resources. The simulations also show that observable benefits from positive changes in agricultural practices would be delayed in time due to the slow dynamics of nitrate transport within the aquifer system.
Résumé(Résumé en langage clair et simple, non publié)
Cette étude analyse l'impact des changements climatiques et des pratiques agricoles sur la qualité de l'eau souterraine de l'Île-du-Prince-Édouard, Canada. En particulier, la qualité liée aux niveaux de nitrates dans l'eau souterraine est étudiée. Les nitrates sont un produit de dégradation des fertilisants naturels et chimiques qui sont utilisés pour la fertilisation agricole. Les résultats de cette étude démontre que les changements de pratiques agricoles et les processus physiques qui contrôle le transport des nitrates dans l'aquifère de l'Île-du-Prince-Édouard, sont beaucoup plus importants que l'effet des changements climatiques eux-mêmes. La mise-en-place de meilleure pratiques agricoles serait donc essentielle pour assurer l'équilibre environnemental et économique de la province.
GEOSCAN ID297575