Wind erosion and aeolian transport processes are under studied compared to rainfall-induced erosion
and sediment transport on burned landscapes. Post-ﬁre wind erosion studies have predominantly
focused on near-surface sediment transport and associated impacts such as on-site soil loss and site fertility. Downwind impacts, including air quality degradation and deposition of dust or contaminants, are also likely post-ﬁre effects; however, quantitative ﬁeld measurements of post-ﬁre dust emissions are needed for assessment of these downwind risks. A wind erosion monitoring system was installed immediately following a desert sagebrush and grass wildﬁre in southeastern Idaho, USA to measure wind erosion from the burned landscape. This paper presents measurements of horizontal sediment ﬂux and PM10 vertical ﬂux from the burned area. We determined threshold wind speeds and corresponding threshold friction velocities to be 6.0 and 20 m s-1, respectively, for the 4 months immediately following the ﬁre
and 10 and 0.55 m s-1 for the following spring months. Several major wind erosion events were measured in the months following the July 2010 Jefferson Fire. The largest wind erosion event occurred in early September 2010 and produced 1495 kg m-1 of horizontal sediment transport within the ﬁrst 2 m
above the soil surface, had a maximum PM10 vertical ﬂux of 100 mg m-2 s-1, and generated a large dust plume that was visible in satellite imagery. The peak PM10 concentration measured on-site at a height of 2 m in the downwind portion of the burned area was 690 mg m-3. Our results indicate that wildﬁre can convert a relatively stable landscape into one that is a major dust source.
Additional Publication Details
Wind erosion from a sagebrush steppe burned by wildfire: measurements of PM10 and total horizontal sediment flux