SNOWMELT AND LOGGING INFLUENCE ON PIEZOMETRIC LEVELS IN STEEP FORESTED WATERSHEDS IN IDAHO

This study was designed to evaluate the effects of clear-cut logging on piezometric levels caused by subsurface flow on steep granitic slopes in the mountains of Idaho. Data were collected on control and treated watersheds both before and after logging. Wildfire burned over both study watersheds less than 1 year after logging. Data collection included a complete weather station adjacent to the study watersheds plus two snow lysimeters, a sample grid of 52 snow stakes for measuring snow-water equivalent, and 25 crest gauge piezometers located on the study watersheds. Snowmelt was the primary factor influencing piezometric levels. Instantaneous and mean daily snowmelt rates were poor predictors of peak levels. Average ablation rates from the time of maximum snow accumulation to the time of disappearance of the snowpack were closely correlated with maximum and average piezometric levels. Logging influenced levels by increasing snow accumulation and melt rates and by changing snow distribution. Maximum and average piezometric levels were increased 41 and 68 percent, respectively, by logging. The data suggest that the frequency of occurrence of maximum levels was increased by up to 10 times by the clearcut logging activities.

Media Info

  • Media Type: Print
  • Features: Figures; Maps; References; Tables;
  • Pagination: pp 1-8
  • Monograph Title: Soil reinforcement and moisture effects on slope stability
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00394984
  • Record Type: Publication
  • ISBN: 0309037220
  • Files: TRIS, TRB
  • Created Date: Nov 30 1985 12:00AM