HR: 0800h
AN: NG41C-0670    [Abstracts]
TI: Post-fire Wind Erosion in a Semiarid Shrub Steppe
AU: * Glenn, N
EM: glennanc@isu.edu
AF: Idaho State University, Dept of Geosciences, 322 E. Front St. Suite 240, Boise, ID 83702, United States
AU: Sankey, J
EM: sankjoel@isu.edu
AF: Idaho State University, Dept of Geosciences, 921 S. 8th Ave, MS 8072, Pocatello, ID 83209, United States
AU: Germino, M
AF: Idaho State University, Dept of Biological Sciences, 921 S. 8th Ave, MS 8007, Pocatello, ID 83209, United States
AB: The objective of this project is to determine and describe the effects of fire on the potential for soil erosion by wind in a semiarid shrub steppe in southeastern Idaho. We apply a previously developed method for determining the threshold wind speed (critical threshold) required to initiate saltation of soil particles at several sampling locations within wildfires that burned in summers 2006 and 2007. Sampling locations have data collection stations with anemometers, a piezoelectric sensor mounted at 5 cm above the ground surface that records impacts from saltating soil particles, temperature and relative humidity sensors mounted at ground level, soil moisture sensors, and soil erosion bridges. Analysis is intended to identify key controlling variables of post- wildfire eolian transport with the intention of continued monitoring over longer time periods with the incorporation of LiDAR data for surface characterization. Initial field results indicate substantial differences in wind erosion potential between burned and unburned sites. Saltation activity is greater and more frequently detected at the burned sites in comparison to the unburned sites. Comparison between the burned sites indicates periods of similar saltation activity and threshold wind speeds. Comparison also shows periods when saltation is detected at one burned site but not the other, and periods when greater wind speeds are required at one burned site to initiate saltation. This suggests that within-burn variability exists in wind erosion potential and requires more complete characterization to accurately model and predict post-fire eolian transport. In parallel to the field-based research, we are developing remote sensing techniques to characterize the soil surface and vegetation communities at a scale appropriate for wind erosion modeling. These techniques include hyperspectral and LiDAR analysis of the soil surface and structural information of the vegetation. Soil and vegetation surface roughness information from LiDAR will be used to compare wind speed thresholds in the field areas. This work has important implications for land rehabilitation, soil conservation efforts, and human health.
DE: 0486 Soils/pedology (1865)
DE: 1625 Geomorphology and weathering (0790, 1824, 1825, 1826, 1886)
DE: 1632 Land cover change
DE: 1809 Desertification
DE: 1855 Remote sensing (1640)
SC: Nonlinear Geophysics [NG]
MN: 2007 Fall Meeting