1 / 8

Major Factors of Wind Erosion and Road Dust

Major Factors of Wind Erosion and Road Dust. Robert Surrago. Background. Fugitive/natural sources make up the majority of PM-10 and PM-2.5 emissions Two main fugitive/natural sources are wind erosion and road dust (mainly from unpaved roads). Wind Erosion - Factors. Wind speed

jace
Download Presentation

Major Factors of Wind Erosion and Road Dust

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Major Factors of Wind Erosion and Road Dust Robert Surrago

  2. Background • Fugitive/natural sources make up the majority of PM-10 and PM-2.5 emissions • Two main fugitive/natural sources are wind erosion and road dust (mainly from unpaved roads)

  3. Wind Erosion - Factors • Wind speed • Wind gusts are more important than average wind speed - best indicator is fastest mile • Used in conjunction with reference height to calculate the friction velocity (u = (u*/0.4) ln(z/zo))

  4. Wind Erosion - Factors • Erosion potential (P) • A function of the friction velocity (u*) & the threshold friction velocity (ut*[observed experimentally]) • If u* < ut*, then there is no chance of wind erosion (cannot overcome friction) • Each event must be treated separately

  5. Road Dust - Factors • Mean vehicle weight - the average weight of all the vehicles that traverse a given road • The more weight, the more force acting on the road  more dust can be created • Surface material silt content - dust emissions vary directly with the % of silt in the road surface material • Varies with geographic location

  6. Road Dust - Factors • Moisture content - more moisture = more particle cohesiveness  less dust created • Can be affected by precipitation • Mean vehicle speed/mean # of wheels • Faster = more force applied to surface = more dust created • More wheels = more opportunities to create more dust • Both are minor factors

  7. Wind and Road Relations • Both emission types have ways to account for frequency of disturbances • Wind - total P is sum of all disturbances • Road - mean vehicle conditions • Both types take into account material properties • Wind - threshold friction velocity • Road - silt and moisture contents

  8. Summary • Factors are similar for fugitive dust emissions • Different applications of factors yields different equations/constants • What does the future hold? • Apply to present data? • Generate emissions projections? • Questions/comments/suggestions

More Related