Modelling hydrologic system change in a paraglacial catchment in the Northern Rocky Mountains

The Northern Rocky Mountains, home to the highest concentration of glaciers in the American West, are undergoing increased rates of climate warming, resulting in previously unseen ecological and hydrological outcomes. Globally, many glacier basins have experienced glacial recession to the threshold point of surpassing peak basin runoff, resulting in substantial decreases in local hydrological yield. Such findings call for models that do not alone examine glacial runoff but a complete examination of changes in the water budget. Alpine catchments are increasingly vulnerable to evapotranspirative losses due to climatic warming, and the rates of vegetation succession are often unable to keep up with the rate of warming. Basin scale analyses of glacial recession on streamflow are then confounded by ecohydrologic dynamics created by primary succession and the associated increase in evapotranspiration. In this study, I present a conceptual framework for modelling basin runoff in landscapes responding to paraglacial adjustment. The study goal was achieved by calibrating and running the Hydrologiska Byråns Vattenbalansavdelning (HBV) model in Swiftcurrent basin and investigating change across the basin water balance through baseflow analysis. The research findings indicate catchment scale changes in the timing and magnitude of the flow regime in the deglaciating Swiftcurrent basin, by employing HBV and empirical baseflow analysis. While most components of the water balance appear consistent across the study period, late summer baseflow values suggest the basin hydrology is undergoing changes, possibly a result of melt occurring earlier in the season. Ultimately, I advocate for an adaptable and accessible approach to understanding paraglacial basins by constructing an estimation of basin-scale water budgets.