winter river
May 19, 2014

How Does Snowfall Affect A River’s Flow?

Gerard LeBlond for - Your Universe Online

New research has shown that the amount of water flowing through rivers is directly affected by the amount of snowfall received.

Less snowfall means the rivers will discharge less water, according to a recent study by PhD student Wouter Berghuijs and Dr Ross Woods, senior lecturer in Water and Environmental Engineering in the Department of Civil Engineering at the University of Bristol. Along with a colleague from Delft University of Technology, they published the research online in Nature Climate Change.

By using historical data gathered from several hundred river basins across the United States, the researchers were able to determine the effect of snowfall on the amount water discharged by the rivers. Previous studies focused on the snowfall within the same year’s stream flow and how much water was in the river that particular year. The new study concentrated on the role of snowfall affecting the flow of water on average in these rivers.

The researchers determined that snowfall is an important factor in the average river discharge and global warming is likely to reduce the amount of snowfall. Even if temperatures rise by only two degrees, the study suggests the amount of water in rivers will decrease as snowfall decreases with warmer temperatures.

“With more than one-sixth of the Earth's population depending on meltwater for their water supply, and ecosystems that can be sensitive to streamflow alterations, the socio-economic consequences of a reduction in streamflow can be substantial. Our finding is particularly relevant to regions where societally important functions, such ecosystem stability, hydropower, irrigation, and industrial or domestic water supply are derived from snowmelt,” the authors of the study said.

The researchers propose that further studies be conducted to respond to the consequences of rising temperatures that cause precipitation to change from snow to rain.