Modelling the Effects of Climate and Landcover Change on the Hydrologic Regime of a Snowmelt‐Dominated Montane Catchment

Climate change poses risks to society through the potential to alter streamflow, and wildfires are projected to increase; however, little is known about their combined effects on hydrology. Using the Raven Hydrological Modelling Framework, we investigate the impacts of climate and landcover changes on the hydrology of a montane forested catchment in southern British Columbia, Canada. The combination of climate change and stand‐replacing landcover disturbance in middle and high elevations is predicted to advance the timing of peak flow by two to nine times (depending on climate projection) more than the advance from disturbance alone (7 days). The combined effects of climate and landcover disturbance on peak flow magnitude are predicted to be offsetting for frequent events, but additive for extreme events. There appears to be a dependency of extreme peak flows on the distribution of landcover. Extreme summer low flows are predicted to become commonplace by the 2050s. Low annual yield is predicted to become more prevalent by the 2050s, but then largely recover by the 2080s. The modelling suggests that landcover disturbance can have a mitigative influence on annual water yield, but minimally for summer low flow. The results highlight the importance of a multifaceted examination of complexity incorporating climate change, landcover change and a large range of hydrological indicators. Moreover, the results indicate that management strategies must assess the interplay of future climate, landcover condition and societal values on watershed risk.