AN INTERDISCIPLINARY APPROACH TO ASSESS WATER RESOURCES ORIGINATING FROM GLACIATED WATERSHEDS

Glacier meltwater contributions to downstream water supply has been increasing in much of the Arctic, likely from higher recent air temperatures. For mountain glaciers that contribute a large portion to downstream discharge, a sustained negative glacier mass balance is concerning to Arctic communities because the water budget will ultimately decline when glacier ice disappears. Glacierized watersheds are complex because the hydrological budget is influenced by precipitation across the entire area, snow melt from both on and off glacier, glacier ice melt, and from water stored at the surface or within the subsurface. In regions where permafrost is prevalent, sub-surface water storage capacity and flow is heavily controlled. This storage capacity and flow is also changing due to thawing permafrost in the rapidly warming Arctic. Unfortunately, glaciological, geological, permafrost, and hydrological studies are typically treated as separate research topics. However, it has become obvious that understanding the complex relationships between these dynamic systems is important for predicting future hydrological budgets, from a water resources perspective. Herein, we discuss the combined use of ground and airborne geophysics, glaciology, meteorology, hydrology, chemistry, and numerical modeling to predict future changes to the water supply originating from a partially glacierized and permafrost-laden watershed. Our study site is Jarvis Creek Watershed in Eastern Alaska which contains a 6-km long glacier that has been in retreat since the 1950’s. Despite its retreat, Jarvis accounts for 15% of the annual downstream discharge into Jarvis Creek. Our results suggest that Jarvis Glacier will entirely disappear by 2100. This prediction, combined with observed decreased local precipitation rates and thawing permafrost, suggest that downstream water budgets will be a significant local community concern in the near-future. We propose that this interdisciplinary approach should be considered by other Arctic communities to develop more accurate water resource predictions in the future.