Alteration of Mean Streamflow and Evaporation Under Snow Loss

Abstract:

In a warming climate, precipitation is less likely to occur as snowfall. A shift from a snow-dominated regime towards a rain-dominated regime is currently assumed to change the seasonal distribution of stream flow, but not to influence the mean stream flow significantly. Contradicting the current paradigm, we argue that mean stream flow is likely to reduce for catchments that experience significant reductions in the fraction of precipitation falling as snow. With more than one-sixth of the Earth’s population depending on melt water for their water supply and ecosystems that can be sensitive to stream flow alterations, the socio-economic consequences of a reduction in stream flow can be substantial.