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SNOWPACK CHANGES RESULTING FROM TIMBER HARVEST INTERCEPTION, REDISTRIBUTION, AND EVAPORATION 1
Author(s) -
Stegman Steven V
Publication year - 1996
Publication title -
jawra journal of the american water resources association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.957
H-Index - 105
eISSN - 1752-1688
pISSN - 1093-474X
DOI - 10.1111/j.1752-1688.1996.tb03503.x
Subject(s) - snowpack , snow , interception , environmental science , surface runoff , canopy , atmospheric sciences , wind speed , hydrology (agriculture) , throughfall , evaporation , tree canopy , snowmelt , canopy interception , soil science , meteorology , soil water , geology , ecology , geography , geotechnical engineering , biology
Three processes were examined as causing snowpack changes in forest clearings. Two of the three contribute to increases and one counteracts by reducing snowpack. The two that increase snowpack are redistribution and decreased loss to interception. Snow evaporation from a clearing counteracts snowpack increases. Research has indicated that as vegetation density increases, so too does the loss to interception. As snow in the canopy reaches the limit that the canopy can hold (the threshold amount) evaporation increases. Aerodynamics of the forest canopy were studied as well. As timber is cut, wind patterns are disturbed, creating disruptions in the wind velocity gradient depositing snow in openings. This redistribution leads to an increased snow water equivalent and augments runoff. Snow evaporation was shown to increase proportionally with opening size. Evaporation offsets the water yield gains derived from forest cut. It was found that this offset is inclusive to the measurements of water yield changes in experimental forests. An optimal size of harvest block may be five tree heights in width as suggested by numerous studies.