INNOVATION March-April 2014

f ea t u r e s

Westerman Award Winner Pioneers Climate Change Modelling in Groundwater

Jean Sorensen

Approximately 25 – 30% of the Canada’s population relies upon groundwater and in some parts of the globe that dependency for life- sustaining water is 100%, says Dr. Diana Allen, P.Geo., this year’s recipi- ent of the C.J. WestermanMemorial Award, and a pioneer and leader in modelling the impact of climate change on groundwater supplies. “In cities such as Vancouver, we don’t think about water,” says Allen. “But, in Langley, a good percentage of water is groundwater still drawn fromwells. In rural areas of BC (particularly in the Okanagan) and in some parts of Canada, this percentage increases. Prince Edward Island, for example, relies 100% on groundwater.” Groundwater has not yet been noticeably impacted in Canada by climate change but without an appreciation of how groundwater is formed and stored, there is a fear that “mining” the natural resource by industry and agriculture will over-tax it in some areas. There is the need to understand how to make it sustainable, she says. Mining underground water refers to withdrawing more water from a settlement area known as an aquifer, than the annual precipitation or natural flows can recharge. Parts of the world such as Northern India and Africa now have population growth that is leading to a decline in groundwater levels, reaching beyond what is sustainable. “For countries such as India and Africa where there is no other source of water, it is a social dilemma,” says Allen. Population growth combined with industry and agriculture all compete. It’s a growing concern that “in 20 to 30 years, groundwater will no longer be available.”

Knowledge of how climate change will impact groundwater supplies and demands allows for early conservation planning in high-risk areas, including identifying alternative sources. BC groundwater resources aren’t expected to see a huge decline due to climate change, as the Province hosts snow-covered mountains and has a wet coastal climate that may buffer the impact in most populated areas, says Allen. But, spot problems may occur. It’s these potential areas that first lead Allen to begin her computer modelling of groundwater supplies. “I became interested in climate change impacts on groundwater about 15 years ago by pure happenstance. I had done some work for the BCMinistry of Environment on the Grand Forks aquifer. I had developed a model of the aquifer to answer specific questions relating to well capture zones and interaction between groundwater and sur- face water,” she says. The model was responsive to changing variables. “I had spent all this time on the model and wanted to do something interesting with it afterwards. I wondered what would happen if I looked at climate change in the future and the impact on sustainability. I published the work and the topic of climate change impact became a huge part of my research.” Amisconception, says Allen, is that groundwater moves rapidly through caverns or pools below the earth’s surface. This is true for areas known as karsts, but generally groundwater moves slowly and is held in place much like in a garden pot. Water, whether it is sourced from a melting snowpack or rainfall, seeps into the soil, fractured rock or gravel and finds its way through crevices or pours to drains into

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