Predicting post-fire hillslope erosion in forest lands of the western United States
Miller, M.E.; MacDonald, L.H.; Robichaud, P.R.; Elliot, W.J. 2011.
Predicting post-fire hillslope erosion in forest lands of the western United States.
International Journal of Wildland Fire 20:982-999.
http://dx.doi.org/10.1071/WF09142
Keywords: ground cover, modelling, sensitivity analysis, WEPP
Links:
Abstract:
Many forests and their associated water resources are at increasing risk from large and severe wildfires due to
high fuel accumulations and climate change. Extensive fuel treatments are being proposed, but it is not clear where such
treatments should be focussed. The goals of this project were to:
(1) predict potential post-fire erosion rates for forests and
shrublands in the western United States to help prioritise fuel treatments; and
(2) assess model sensitivity and accuracy.
Post-fire ground cover was predicted using historical fire weather data and the First Order Fire Effects Model. Parameter
files from the Disturbed Water Erosion Prediction Project (WEPP) were combined with GeoWEPP to predict post-fire
erosion at the hillslope scale. Predicted median annual erosion rates were 0.1–2 Mg ha-1 year -1
for most of the intermountain west, ~ 10–40 Mg ha-1 year -1 for wetter areas along the
Pacific Coast and up to 100 Mg ha-1 year -1 for north-western California.
Sensitivity analyses showed the predicted erosion rates were predominantly controlled by the
amount of precipitation rather than surface cover. The limited validation dataset showed a reasonable correlation between
predicted and measured erosion rates (R2=0.61), although predictions were much less than measured values. Our results
demonstrate the feasibility of predicting post-fire erosion rates on a large scale. The validation and sensitivity analysis
indicated that the predictions are most useful for prioritising fuel reduction treatments on a local rather than interregional
scale, and they also helped identify model improvements and research needs.
Moscow FSL publication no. 2011m
|