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

Abstract

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. Copyright © 2013 John Wiley & Sons, Ltd.

Long-term trends in groundwater recharge and discharge in a fractured bedrock aquifer – past and future conditions

“…baseflow, spring flow, peatland-aquifer interactions) stemming from different future recharge scenarios (e.g. Scibek and Allen 2006;Jyrkama and Sykes 2007;Scibek et al 2007;Toews and Allen 2009;Sulis et al 2011;Bourgault et al 2014;Kurylyk et al 2014;Levison et al 2014a;Levison et al 2014b;Rivard et al 2014) or historical data sets (e.g. Chen et al 2004;Rivard et al 2009).…”

Impacts of changes in groundwater recharge on the isotopic composition and geochemistry of seasonally ice-covered lakes: insights for sustainable management

“…The model includes a terrain-following vertical coordinate based on hydrostatic pressure (Laprise, 1991;Alexandru and Sushama, 2015), and an horizontal discretization on a rotated latitude-longitude, Arakawa C grid (Arakawa and Lamb, 1977;Alexandru and Sushama, 2015). Following CRCM4, changes that have been introduced into CRCM5 include, for example, evolution in the planetary boundary layer parameterization to suppress both turbulent vertical fluxes under very stable conditions and the interactively coupled one-dimensional lake model (Flake; Mironov et al, 2010;Martynov et al, 2012;Šeparović et al, 2013).…”

“…In addition, it is predicted to shift differentially under various climate scenarios and models (Jyrkama and Sykes, 2007;Levison et al, 2014). In Canada, highly variable recharge rates have been proposed in previous studies, for example, for the 2050 horizon (mainly the period 2041-2070) relative to modern (2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015) or past recharge rates , depending on study site, scenario, and model: +10 to +53 % in the Grand River watershed, Ontario (Jyrkama and Sykes, 2007), −41 to +15 % in the Chateauguay River watershed, Quebec (Croteau et al, 2010), −6 to +58 % in the Otter Brook watershed, New Brunswick (Kurylyk and MacQuarrie, 2013), −4 to +15 % at Covey Hill, Quebec (Levison et al, 2014), +14 to +45 % in the Annapolis Valley, Nova Scotia (Rivard et al, 2014), and −28 to +18 % for the Magdalen Islands, Quebec (Lemieux et al, 2015).…”

Modeling cross-scale relationships between climate, hydrology, and individual animals: generating scenarios for stream salamanders

“…Conversely, no real consensus can be observed during the summer and autumn, where precipitation changes vary from −19 to +33%. More details on the climate scenarios can be found in Levison et al (2014a).…”

“…Climate change impacts on groundwater resources at a regional scale are increasingly studied (Jyrkama and Sykes, 2007;Scibek et al, 2007), but the magnitude of these changes is highly uncertain (Green et al, 2011). In particular, headwater basins have been the focus of only limited research (Levison et al, 2014a) and the impacts of climate change on habitat suitability for spring-restricted animals, such as many salamanders, remain largely unknown. However, depending on the extent and timing of the changes with respect to the species' life cycle, the impact could be very different from one part of the species' geographic range to another.…”