DUST REDUCTION EFFICIENCY OF A SINGLE-ROW VEGETATIVE BARRIER (MACLURA POMIFERA)

摘要

Little is known about the dust removal efficiency of common vegetative barriers. This study of blowing dust reduction was conducted on one of the most common vegetative barriers used for wind erosion control in Kansas and the U.S. Great Plains, the deciduous tree species Maclura pomifera (Osage orange). A dust generator and distributor were fabricated to generate dust particles for determining the dust removal efficiency of a single-row Osage orange barrier. Simultaneous upwind and downwind dust concentrations were measured using mini-vol samplers for total suspended particulates (TSP) at heights of 1.5, 3.0, 4.5, and 6.0 m above the ground. Measurements were made using two towers located at upwind and downwind distances equal to the height of the barrier. Particle size distribution (PSD) analysis of the initial generated dust showed that most particles were large (GMD = 102.8 mu m), while about 5% of the dust was particulate matter less than 2.5 mu m in diameter (PM2.5) and 15% was less than 10 mu m (PM10). Laser diffraction analysis of particles from the sample filters was used to determine the dust reduction efficiency of the barrier. Results showed that dust reduction was significantly related to reduction in wind speed at lower heights, causing an overall decrease in dust concentration as particles passed through the barrier. Concentrations of larger particles (similar to 100 mu m) were also reduced relative to smaller particles when dust passed through the barrier. The data also showed that 4.5 m above the ground, near the crown of the canopy, was most efficient at removing the PM2.5 (15% to 54%) and PM10 (23% to 65%) fractions of the generated dust.