USGS Washington Water Science Center
|Project Home | Publications and Products | Project Summaries | Partnerships ||
Runoff from rain falling on snow has been associated with mass-wasting of hill slopes, damage to river banks, downstream flooding, and associated damage and loss of life. In Washington, forest managers, among others, are concerned about the effects that timber harvesting may have on runoff during rain-on-snow events. Available data indicate that rain falling on snow in open areas produces more water available for runoff than does rain falling in forested areas.
Forest managers and others would like to know how much water is available for runoff when various types of storms drop rain on various types of snowpack in open areas, and how frequently specific storm conditions are expected in the rain-on-snow zone of western Oregon and Washington.
To help forest managers and others better understand runoff from rain on snow, the USGS is using a numerical computer model to investigate the effects of different rain-storm and snowpack conditions in open areas on the amount of water available for runoff in the western Cascades of Washington and Oregon. Hydrologists are comparing the results with information on the amount and frequency of water available for runoff from rainfall only, and determining the frequency of occurrence of different rain storms in snow areas.