A review of simulated climate change impacts on groundwater resources in Eastern Canada

Abstract

In Eastern Canada, groundwater is the main water supply for most of the rural regions and in many large urban communities. An understanding of the impacts of climate change on this resource is crucial for sustainable water management in this region. The objectives of this paper was to summarize the state of knowledge about possible climate change impacts on groundwater dynamics in Eastern Canada, thus providing a clearer understanding of future conditions. Twenty-two studies are reviewed including Ontario, Québec, New Brunswick, Nova Scotia, and Prince Edward Island, to identify the impacts on groundwater recharge and river baseflows. The studies disagree in their estimates of changes in future recharge conditions, and no trend from West to East was revealed. This could be due to the use of different modelling approaches (model type, climate change scenario, future horizon). Nonetheless, more inter-annual variability during the summer and earlier snowmelt periods causing seasonal shifts in the recharge cycle are expected. The studies show that base flows could decrease, which could induce critical conditions for water supplies and for ecosystems. This review provided new insights that lead to the following recommendations for future studies: 1) use a variety of climate models and emission scenarios; 2) promote the use of integrated models when possible; 3) study long-term climate change impacts on groundwater resources at different scales; 4) simulate the combined effects of climate change and other pressures; and 5) develop models that cover other regions of Eastern Canada as dictated by stakeholders and water managers.