Climate change effects on the snowmelt hydrology of western North American mountain basins

Several effects of increasing atmospheric CO₂ content on climate are considered-namely, increasing atmospheric temperature, changing snowmelt equivalent at the beginning of the snowmelt, and changing precipitation during the snowmelt runoff season. The effects that these changes would have on runoff from mountain basins were evaluated by use of the snowmelt runoff model (SRM). The major effect on runoff was caused by increasing temperature. An increase in total seasonal runoff resulted, but the more interesting and significant effect was a redistribution of runoff to the months April and May. Depending on whether snowmelt season precipitation and winter snow accumulation increased or decreased, the temperature effect on the hydrograph was magnified or diminished. The model results indicated a potentially serious problem in western North America where climate changes could widen the gap between water supply and water demand as well as causing existing water storage and distribution systems to be ineffective