Three years of hillslope sediment yields following the Valley Complex fires, western Montana

Robichaud, Peter R.; Wagenbrenner, Joseph W.; Brown, Robert E.; Spigel, Kevin M. 2009. Three years of hillslope sediment yields following the Valley Complex fires, western Montana. Res. Pap. RMRS-RP-77. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 8 p.

Keywords: erosion, rainfall intensity, soil water repellency, vegetative recovery, post-fire, sediement yield, Montana

Links: PDF [815 KB]

Abstract: The 2000 Bitterroot Valley wildfires provided an opportunity to measure post-fire effects and recovery rates. We established 24 small (0.01 ha [0.02 acre]) plots in four high-severity burn sites. We measured sediment yields at each site with silt fences. We also measured rainfall characteristics, soil water repellency, vegetative cover, and other site characteristics. The median sediment yield in post-fire year 1 was 8 Mg ha^-1 yr^-1 (3.6 ton acre^-1 yr^-1), and values ranged from 0.3 to 47 Mg ha^-1 yr^-1 (0.1 to 21 ton acre^-1 yr^-1). Sediment yields were lower in post-fire years 2 and 3, with medians of 2 and 0.3 Mg ha^-1 yr^-1 (0.9 and 0.1 ton acre^-1 yr^-1), respectively. The high variability in sediment yields was related to 10-minute maximum rainfall intensity (I₁₀), but not to soil water repellency or vegetative cover. The results of this study may assist in decisions about post-wildfire land management.

Moscow FSL publication no. 2009q