Dust Emission 'Hotspots' Along the Highway Systems in the Southwestern United States: An Integrated Measuring, Modeling, and Predictive Stud

Threshold Shear Velocity (TSV), the velocity required for soil surface dust particles to become airborne, was calculated from the in-situ measurements of the soil surface and subsurface soils from these hotspots. These in-situ measurements were soil texture, soil volumetric moisture content, gaps between vegetation, vegetative canopy heights, and soil surface crusting.;Nearly 500 dust emission "hotspots" were identified along with their associated geomorphic and land cover features. Five buffer ranges were used, 500m, 1 km, 2 km, 5km, and 10 km to categorize these hotspots. With each increase in buffer range more hotspots were identified but for this project only hotspots close in proximity to major highways were considered. A close examination of all the hotspots revealed that as the buffer ranges increased clustering of hotspots became more evident making it more difficult to differentiate individual hotspots. This lead to the decision to let 1 km be the optimum buffer range that would be used for the project. Within the 1 km buffer, 55 dust emission hotspots and 4 playas met the criteria to be further studied.;The results and findings of this project will be released to land managers, policy makers, and highway authorities with the sincere hope that these results would aid them in making timely, critical life-saving decisions pertaining to highway safety and traffic management. This research may not only be relevant in the southwestern United States but have worldwide implications wherever blowing dust may present a hazard to highway safety.