Potential trends in snowmelt-generated peak streamflows in a warming climate

Abstract

Previously reported impacts of climate warming on streamflow peaks are varied, and the controls on the variations remain unclear. Using physically based linked snowpack and watershed hydrological models, we evaluated the potential changes in seasonal snowmelt-generated streamflow peak (Qmax) due to warming in a small semiarid mountain watershed. Results suggest that the trend in Qmax with warming is strongly governed by the conversion of precipitation phase, accumulated snow amount prior to the melt season, and snowmelt rate during the ablation period. Under a warming climate, the trend in Qmax is expected to be decreasing for relatively warm regions but increasing for cold regions. Climate regimes that are most susceptible to dominant precipitation phase transitions from snow to rain are likely to experience larger decreases in Qmax with warming. This study serves as a first step toward assessing the varied impacts on Qmax due to warming vis-a-vis the specific catchment hydroclimatology.