Assessing hydroclimatic impacts of climate change in snowy catchments using a physically based hydrological model

This study focuses on 34 snowy catchments in Southern Quebec, Canada, characterized by diverse physiographic and hydrometeorological conditions. The region is particularly vulnerable to climate change due to its cold, snow-dominated hydrology and significant seasonal variability in temperature and precipitation. The study evaluates future hydroclimatic changes using the Water flow and balance Simulation Model (WaSiM), a physically based distributed hydrological model. Hydroclimatic variables, including precipitation, snow water equivalent (SWE), streamflow, evapotranspiration, soil moisture, and groundwater recharge, were analyzed for reference (1981–2010) and future (2070–2099) periods. The findings reveal significant shifts from snowfall to rainfall, reduced snow accumulation, and earlier snowmelt, leading to altered seasonal streamflow patterns, increased winter low flows, and earlier peak flows. Groundwater recharge and evapotranspiration are projected to rise during colder months, while surface runoff is expected to decline. In addition to analyzing individual variables, the study highlights how climate change alters the relationships between key hydrological processes, such as those linking groundwater recharge, soil moisture and evapotranspiration. These interdependencies underscore the importance of adopting a holistic approach to assess climate change impacts on the water cycle. • Identified snow-to-rain shifts and their cascading effects on the water cycle. • Showed the interconnected nature of hydrological processes under climate change. • Offered spatial insights to support adaptive water management in snowy catchments.