Dynamics of a headwater system and peatland under current conditions and with climate change

Levison, J.; Larocque, M.; Fournier, V.; Gagné, S.; Pellerin, S. et Ouellet, M.A. (2014). « Dynamics of a headwater system and peatland under current conditions and with climate change ». Hydrological Processes, 28(17), pp. 4808-4822.

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Résumé

Interactions between headwater aquifers and peatlands have received limited scientific attention. Hydrological stresses, including those related to climate change, may adversely impact these interactions. In this study, the dynamics of a southern Québec headwater system where a peatland is present is simulated under current conditions and with climate change. The model is calibrated in steady state on field-measured data and provides satisfactory results for transient-state conditions. Under current conditions, simulations confirm that the peatland is fed by the fractured bedrock aquifer year-round and provides continuous baseflow to its outlets. Climate change is simulated through its impact on groundwater recharge. Predicted precipitation and temperature data from a suite of regional climate model scenarios provide a net precipitation variation range from +10% to −30% for the 2041–2070 horizon. Calibrated recharge is modified within this range to perform a sensitivity analysis of the headwater model to recharge variations (+10%, −15% and −30%). Total contribution from the aquifer to rivers and streams varies from +14% to −44% of the baseline for +10% to −30% recharge changes from spring 2010 data, for example. With higher recharge, the peatland receives more groundwater, which could significantly change its vegetation pattern and eventually ecosystem functions. For a −30% recharge, the peatland becomes perched above the aquifer during the summer, fall and winter. Recharge reductions also induce sharp declines in groundwater levels and drying streams.

Type:	Article de revue scientifique
Informations complémentaires:	This is the peer reviewed version of the following article: Levison, J., Larocque, M., Fournier, V., Gagné, S., Pellerin, S. et Ouellet, M.A. (2014). Dynamics of a headwater system and peatland under current conditions and with climate change. Hydrological Processes, 28(17), 4808-4822. , which has been published in final form at http://dx.doi.org/10.1002/hyp.9978. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
Mots-clés ou Sujets:	Peatland, headwater system, climate change, groundwater flow modelling, Covey Hill, southern Quebec, Canada
Unité d'appartenance:	Centres institutionnels > Centre pour l'étude et la simulation du climat à l'échelle régionale (ESCER) Faculté des sciences > Département des sciences de la Terre et de l'atmosphère
Déposé par:	Marie Larocque
Date de dépôt:	21 mars 2016 14:24
Dernière modification:	19 avr. 2016 18:07
Adresse URL :	http://archipel.uqam.ca/id/eprint/7988

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