Erosion processes and prediction in NW U.S. forests.

Elliot, W.J.;Robichaud, P.R.; Foltz, R.B. 2011. Erosion processes and prediction in NW U.S. forests. ISELE Paper Number 11002. International Symposium on Erosion and Landscape Evolution. 18-21 September 2011, Anchorage, Alaska. ASABE Publication Number 711P0311cd. 8 p.

Keywords: Forest fire, Forest roads, Slope stability, WEPP

Links: PDF [204 KB]

Abstract: The greatest amounts of forest erosion usually follow infrequent wildfires. Sediment from these fires is gradually routed through the stream system. The forest road network is usually the second greatest source of sediment, generating sediment annually. Erosion rates associated with timber harvest, biomass removal, and prescribed fire are generally minimal with current management practices. Landslides and debris flows can contribute significant amounts of sediment during infrequent wet years, or following wildfire. A relatively new source of sediment in forested watersheds is from recreation, particularly all-terrain vehicle trails. Stream channels store and route sediment, but in the absence of channel disturbance, tend to reach an equilibrium condition where sediment entering a given reach is balanced by sediment carried on downstream. At times this sediment from roads, wildfire or landslides may accumulate in channels until higher flow rates, often associated with rainfall on melting snow, flush it downstream. Predictive tools to aid in estimating long term, low level sedimentation from undisturbed forests, and erosion from sediment delivery from roads, and short term, event driven sediment from disturbed forests have been developed. The Water Erosion Prediction Project (WEPP) model has been parameterized for these surface erosion processes, and soil and vegetation databases for these conditions are distributed with the WEPP Windows interface, and our online and GIS interfaces. The internet interfaces were developed to allow users to more easily predict soil erosion for a wide range of climatic and forest conditions, including roads, fires, and timber harvest. The interfaces have been designed to allow users to compare the effects of the most common management practices for each application.

Moscow FSL publication no. 2011g