Tuesday, November 14, 2006 - 10:15 AM
138-4

Deposition of Road Dust on Vegetation.

Dick Gebhart, U.S. Army Eng. Res. and Dev. Cntr, 2902 Newmark Dr., Champaign, IL 61826-9005

  Vehicle movement during training activities on unpaved surfaces at U.S. Army installations generates significant particulate matter (PM) emissions consisting mostly of fugitive dust.  However, localized terrain features, topography, groundcover, wind, and other atmospheric conditions can have significant impact in limiting the portion of PM/dust emissions that are regionally transportable.  In particular, recent dust plume profiling tests show that vegetative groundcover (oak and cedar trees) bordering an emission source captures fugitive dust at rates that significantly exceed the levels represented in standard air plume dispersion models used for regulatory compliance purposes.  The purpose of the field testing and modeling representation described in this paper was to assess the effectiveness of tall prairie grass in capturing particulate matter (PM) emissions from military training exercises.  Field testing was performed in 2005 at two locations: Fort Riley, Kansas, and the Midwest Research Institute (MRI) Deramus Field Station in Grandview, Missouri.  In this testing, the effectiveness of particle capture on tall grass and mowed grass was determined using a standard plume profiling method.  The types of grasses tested, in addition to the trees previously tested, provide a range of vegetative characteristics that are thought to relate to dust capture efficiency.  The efficiency of dust control is a function of vegetative height, leaf area index, vegetative density, and wind speed.