The Role of Basin Geometry in Mountain Snowpack Responses to Climate Change

Snowmelt contributions to streamflow in mid-latitude mountain basins typically dominate other runoff sources on annual and seasonal timescales. Future increases temperature changes precipitation will affect both snow accumulation timing magnitude, but the underlying fundamental roles of basin geometry hypsometry snowmelt sensitivity have received little attention. To investigate role sensitivity, a linear model Cold Regions Hydrological Modeling (CRHM) platform driven are used estimate how affects basin-wide volumes runoff. Area-elevation distributions for fifty western Canada were extracted, normalized according their elevation statistics, classified into three clusters that represent top-heavy, middle, bottom-heavy basins. Prescribed air alter gradient total energy, leading snowpack volume reductions (10–40%), earlier melt onsets (1–4 weeks) end season (3 weeks), early spring rates areal (up 50%). Basin controls magnitude response. The most sensitive bottom-heavy, greater proportion area at low elevations. least high Basins with similar proportional areas elevations fall between others terms metrics. This work provides context anticipating impacts ongoing hydrological change due climate change, guidance monitoring networks distributed modeling efforts.