HR: 0800h
AN: H31D-0436    [Abstracts]
TI: Ground saturation following various harvest patterns: implications of assessing a hydrologic model versus statistical analysis
AU: * Johnson, A C
EM: ajohnson03@fs.fed.us
AF: PNW Forestry Sciences Laboratory, 2770 Sherwood Lane, Suite 2a , Juneau, AK 99801 United States
AU: Vache, K
EM: Kellie.Vache@oregonstate.edu
AF: Oregon State University, Peavy Hall, Corvalis, OR 97331-4316 United States
AU: Edwards, R
EM: rtedwards@fs.fed.us
AF: PNW Forestry Sciences Laboratory, 2770 Sherwood Lane, Suite 2a , Juneau, AK 99801 United States
AB: We assessed groundwater response to various harvest intensities in southeast Alaska. Observations of peak water table heights in 56 groundwater-monitoring wells at two study locations \(Hanus and Portage\) suggest that soil saturation levels on hillslopes differed significantly with harvest intensity only at Portage Bay following 25, 75, and 100% harvest. Before the forest at Portage Bay was cut by 100%, the average rainfall needed for 50% saturation of the soil was 54 mm, but after clearcutting soils reached 50% saturation with only 21 mm. We hypothesize that Hanus Bay sites lacked statistically significant differences in levels of saturation following harvest due to several factors: 1\) location, size, and landform of areas contributing to wells, and 2\) number, species, size, and density of trees in relationship to wells for pre and post-harvesting conditions. To test these hypotheses, we developed a simple hydrologic model to predict saturation. Model results were tested with existing records of saturation for various levels of rainfall to estimate which factors influenced observed patterns.
DE: 1803 Anthropogenic effects
DE: 1824 Geomorphology (1625)
DE: 1836 Hydrologic budget (1655)
DE: 1875 Unsaturated zone
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting