Hillslope and groundwater contributions to streamflow in a Rocky Mountain watershed underlain by glacial till and fractured sedimentary bedrock

Abstract. Permeable sedimentary bedrock overlain by glacial till leads to large storage capacities and complex subsurface flow pathways in the Canadian Rocky Mountain region. While some inferences on release of water can be drawn from conceptualizations runoff generation (e.g., thresholds hydrologic connectivity) physically similar watersheds, relatively little research has been conducted snow-dominated watersheds with multilayered permeable substrates that are characteristic Mountains. Stream source (rain, snowmelt, soil water, hillslope groundwater, groundwater) were sampled four sub-watersheds (Star West Lower, Star Upper, East Upper) Creek, SW Alberta, characterize spatial temporal variation contributions streamflow upper lower reaches this watershed. Principal component analysis was used determine relative dominance timing over 2014 2015 seasons. An initial displacement stored winter (reacted rather than unreacted snowmelt rainfall) occurred at onset before stream discharge responded significantly. This followed a dilution effect as saturated landscape, recharged connected hillslopes stream. Fall baseflows dominated either riparian or groundwater West. Conversely, East, composition August but plotted outside boundary measured sources September October. The chemical seeps same trend consistently cold temperatures suggested deep likely late fall streamflow. Temperature signatures also suggest highly pathways. insights gained help improve our understanding processes which is released structures.