Prospective Climates, and Water Availabilities under Different Projections of Environmental Changes in Prince Edward Island, Canada

Climate change impacts on temperatures, precipitations, streamflows, and recharges were studied across eastern, central, and western Prince Edward Island (PEI) between climate normals in 1991-2020, 2021-2050, and 2051-2080 using observed and projected data, and SWAT modeling. Average annual temperature can significantly rise from the existing 5.90-6.86 degrees C to 8.26-11.09 degrees C in different parts during the next 30-60 years under different RCP scenarios. Average annual precipitations would not significantly change except in western PEI where a 17% likely increase would offset further warming impact; therefore, current streamflows (~650 mm/year) and recharges (~320 mm/year) would not be much affected there. However, warming and increased pumping together in its Wilmot River watershed could reduce streamflows up to 9%, and 13% during 2021-2050, and 2051-2080, respectively. In the eastern forest-dominated Bear River watershed, no significant reductions in current streamflows (~692 mm/year) or recharges (~597 mm/year) are expected. Nevertheless, near constant precipitation and warming could cumulatively reduce streamflows/recharges up to 8% there, as pumping will be negligible. In the central zone, precipitation could insignificantly increase up to 5%, but current streamflows (~737 mm/year) and recharges (~446 mm/year) would not be significantly affected, except for RCP8.5 under which streamflows could reduce by ~16% during 2051-2080. Overall, more attenuated streamflows and recharges are likely with higher quantities in late winter and early spring, and somewhat lesser ones in summer, which could reduce water supplies during the growing season. Besides, precipitation uncertainty of ~300 mm/year between dry and wet years continues to be a major water management challenge. Adapting policies and regulations to the changing environment would ensure sustainable water management in PEI.

Automated summary

This study investigates the impacts of climate change on temperatures, precipitations, streamflows, and recharges in different regions of Prince Edward Island. The results show that average annual temperatures are projected to significantly rise in the next few decades, with a potential increase in precipitation in western PEI offsetting further warming impacts. Streamflows and recharges are expected to be affected differently across the regions, with some areas experiencing a decrease. The uncertainty of precipitation between dry and wet years remains a major challenge for water management.