A watershed-scale study of climate change impacts on groundwater recharge (Annapolis Valley, Nova Scotia, Canada)

Abstract

The potential impacts of future climate change on the evolution of groundwater recharge are examined at a local scale for a 546-km 2 watershed in eastern Canada. Recharge is estimated using the infiltration model Hydrologic Evaluation of Landfill Performance (HELP), with inputs derived from five climate runs generated by a regional climate model in combination with the A2 greenhouse gas emissions scenario. The model runs project an increase in annual recharge over the 2041-2070 period. On a seasonal basis, however, a marked decrease in recharge during the summer and a marked increase during the winter are observed. The results suggest that increased evapotranspiration resulting from higher temperatures does not offset the large increase in winter infiltration. In terms of individual water budget components, clear differences are obtained for the different climate change scenarios. Monthly recharge values are also found to be quite variable, even for a given climate scenario. These findings are compared with results from two regional-scale studies.

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

“…Therefore, the future recharge dynamics determined for the Annapolis Valley are assumed to be similar to those of the present study sites. Rivard et al (2014) found that all scenarios predict an annual recharge to the aquifer within the range of +14 to +45 % higher than at present by 2041-2071. They also predict, on a seasonal basis, that recharge will undergo (i) a marked decrease in summer (from 4 to 33 %) and (ii) a spectacular increase in winter (more than 200 %), due to an earlier melt period starting date.…”

“…Over this period, recharge is adjusted to fit the calculated lake isotopic compositions to those measured. In the second step, the results of Rivard et al (2014) was chosen for the simulation of recharge scenarios, since this study focusses on the Annapolis Valley (Nova Scotia, Canada), not far from southern Quebec and with a similar latitude, geology, and climate. Therefore, the future recharge dynamics determined for the Annapolis Valley are assumed to be similar to those of the present study sites.…”

“…The impact of climate change on groundwater recharge is not easy to determine, because of the complexity of interactions and processes involved, and can vary vastly depending on regions (Rivard et al, 2014;Crosbie 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).…”

“…While aquifer recharge is crucial to supporting sustainable management of regional groundwater resources, it is difficult to accurately estimate, owing mainly to limited data availability, as well as limitations inherent to estimation methods and field measurements (Rivard et al, 2013). Recharge rates are controlled by geology, soil characteristics, topography, land cover, land use, and climate (Rivard et al, 2014). Thorough literature reviews of the various techniques that exist to quantify groundwater recharge are provided in Scanlon et al (2002) and Healy (2011).…”

“…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).…”