Vulnerability of northern water supply lakes to changing climate and demand

Michael Bakaic,Andrew S Medeiros

doi:10.1139/as-2016-0029

Abstract

Arctic regions face a unique vulnerability to shifts in seasonality, which influences the summer recharge potential of freshwater reservoirs caused by decreased precipitation and increased evaporative stress. This pressure puts small remote northern communities at risk due to limited existing freshwater supply. The lack of baseline knowledge of existing supply, demand, or reservoir recharge potential increases this risk. We therefore address this knowledge gap through a water resource assessment of municipal supply over a 20 year planning horizon in two communities in Arctic Canada using a novel heuristic model and existing data sources. We generated climate and demand scenarios to identify the mechanisms of drawdown as well as examine the influences on replenishment. We found a pronounced vulnerability to reduced winter precipitation and (or) increased ice thickness of reservoirs. Our heuristic supply forecasts indicate an immediate need for freshwater management strategies for northern communities in Canada.

Highlights

Expanding populations, resource development, and limited infrastructure and capacity has made sustainable water resources a primary issue for northern peoples
While warming in northern regions is generally predicted to coincide with an increase in precipitation (Rawlins et al 2010), there is a large variability between northern regions in model predictions and observations (Prowse et al 2006; Bring and Destouni 2014)
While a 1.8 %/dec increase of snowfall was observed in Iqaluit, summer precipitation decreased by 6.9 %/dec

Summary

Introduction

Resource development, and limited infrastructure and capacity has made sustainable water resources a primary issue for northern peoples. Draft historically experience relatively small amounts of runoff or recharge during the dry summer months due to low precipitation (Schindler and Smol 2006; Woo et al 2006) the natural reservoir capacity of these regions to support human populations is environmentally limited. Recent environmental change has further strained northern water supplies due to observed reductions in precipitation, reduced long term snow cover, and an increase in the high sun season leading to evaporative drawdown (Woo 2010; Carrol et al 2011). The influence of environmental change on the sustainability of northern water supplies is a concern (Alessa et al 2008; Evengard et al 2011). Since water governance systems in northern regions are at an early-stage of evolution, especially in the Canadian Arctic, we seek to examine key vulnerabilities and facilitate the development of freshwater policy for accessible freshwater

Results

Discussion

Conclusion