关键词: |
Highway safety, Land use, Southern Plains Region, Blowing dust, Management decisions, Remote sensing, New Mexico, Oklahoma, Texas (state), Chain-reaction traffic accidents, Visibility |
摘要: |
Windblown dust poses a significant hazard to highway safety. Dust contributes to chain-reaction traffic accidents every year in the southwestern US, however, no known studies have specifically investigated this issue in New Mexico, Oklahoma, and Texas. In this study, we used remotely sensed and in situ observations of land cover, soil, and vegetation data to 1) identify the spatial and temporal distribution patterns of hotspots that may contribute dust blowing across highways in the southwestern United States, 2) identify the characteristics of the dust emission hotspots in relation to the distribution of highway, geomorphology, and land use, and 3) classify the hotspotsfor the potential of blowing dust production based upon field observations and dust emission modeling. A total of 620 total hotspots were identified for the period of 2010-2016 in the study area. Among all these dust emission sources, 234 (38%), 164 (27%), and 141 (23%) are located on cropland, shrubland, and grassland, respectively. An analysis relating the distribution of dust sources and drought intensity in the study area showed that the dust points with highest drought intensities are concentrated on the Southern High Plains region, more specifically in a belt extending from the west to the south of Lubbock, Texas. We further investigated 55 of the dust emission sites, which are located <1km to adjacent highways. Field investigations and laboratory analysis showed that soils at these hotspot sites are dominated by sand and silt particles with threshold shear velocities ranging from 0.17-0.78 m s-1. Dust emission modeling showed that 8 hot-spot sites could produce annual emissions of >5.32 kg m-2, yielding highly hazardous dust emissions to ground transportation with visibility <200 m. Results of location, timing, and magnitude of the dust production at the hotspots are critical information for highway authorities to make informed and timely management decisions when wind events strike. |