Mountain Groundwater data from Canada and the US

This data and R code accompanies a submitted journal article. The manuscript abstract is as follows:

Mountains have a critical role in freshwater supply for downstream populations. As the climate changes, groundwater stored in mountains may help buffer the impacts to declining water resources caused by decreased snowpack and glacier recession. However, rising air temperatures can alter the timing and quantity of snow and increase ice melt, potentially affecting mountain groundwater recharge. Given the scarcity of groundwater observation wells in mountain regions, it remains unclear how mountain groundwater is being impacted by climate change and how this response may differ across ecoregions.

This study quantifies temporal trends in mountain groundwater levels and explores how various climatic, physiographic, and anthropogenic factors affect these trends. This assessment is accomplished by compiling data from observation well networks across Canada and the United States. The resulting dataset contains 171 mountain wells with at least 20 years of continuous monthly data. The Mann-Kendall test for monotonic trend revealed that 54% of these wells have statistically significant temporal trends (p < 0.05) over the period of record, of which 69% were negative and therefore indicating declining groundwater storage. Wells in the western mountain ranges showed stronger trends (both positive and negative) than the eastern mountain ranges, and higher elevation wells showed fewer negative trends than the low elevation wells (p < 0.05). Correlation, regression, and Kruskal-Wallis tests revealed that lower-elevation mountain regions with higher average annual temperatures and lower average annual precipitation are seeing the greatest declines in groundwater storage under climate change. The findings demonstrate that the impact of climate change on mountain water resources extends to the subsurface, with important implications for global water resources.