Applying wind erosion and air dispersion models to characterize dust hazard to highway safety at Lordsburg Playa, New Mexico, USA

Authors: EIBEDINGIL, IYASU - University Of Texas - El Paso; GILL, THOMAS - University Of Texas - El Paso; Van Pelt, Robert - Scott; Tatarko, John; LI, JUNRAN - University Of Tulsa; LI, WENEHAI - University Of Texas - El Paso

Submitted to: Atmosphere
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/5/2022
Publication Date: 10/9/2022
Citation: Eibedingil, I.G., Gill, T.E., Van Pelt, R.S., Tatarko, J., Li, J., Li, W. 2022. Applying wind erosion and air dispersion models to characterize dust hazard to highway safety at Lordsburg Playa, New Mexico, USA. Atmosphere. 13(10). https://doi.org/10.3390/atmos13101646.
DOI: https://doi.org/10.3390/atmos13101646

Interpretive Summary: Periodically dry playa lakebeds are potent sources of dust in semi-arid and arid regions globally. One such dry lakebed, Lordsburg Playa in southwestern New Mexico, is bisected by an interstate highway and dust emanating from the dry lakebed has caused visibility-related crashes that have claimed dozens of lives since the highway was built 50 years ago. Two USDA scientists from different research units along with university personnel from two universities applied computer models of dust emission (SWEEP) and dust transport (AERMOD) to attempt to recreate dust events using meteorological data from local weather stations owned and operated by the New Mexico Department of Transportation (TXDOT). We found that the models did a good job of predicting the emission and transport of dust from two potential dust sources and two dates when compared with webcam footage of traffic on the highway and visibility data from the meteorological stations. These results indicate the utility of using computer models of dust emissivity and transport to predict and proactively mitigate potentially lethal dust hazards.

Technical Abstract: Lordsburg Playa, a dry lakebed in the Chihuahuan Desert of southwestern New Mexico (USA), is crossed by Interstate Highway 10 (I-10). Clouds of dust blowing from the playa across the road threaten highway safety and have caused dozens of fatal accidents. We used two numerical models in combination- the U.S. Department of Agriculture’s Single-Event Wind Erosion Evaluation Program (SWEEP) and the American Meteorological Society and U.S. Environmental Protection Agency Regulatory Model (AERMOD), to simulate and predict the generation and dispersion of windblown soil, dust and PM10 from playa hotspots and estimate PM10 concentrations experienced downwind. The combined models predicted dust plumes originating on the playa- including large, highly emissive areas away from the highway as well as smaller, less emissive sites directly upwind of the interstate- can lead to PM10 concentrations at the hourly scale of tens to hundreds of thousands of micrograms per cubic meter. The results from the modeling were consistent with observations from traffic webcam photos and visibility records from the meteorological sites. Lordsburg Playa sediment contains metals, as will its dust, but exposures to humans will be short-term and infrequent. This study was the first to successfully combine the SWEEP wind erosion model and the AERMOD air dispersion model to evaluate PM10 dispersion in a playa environment. With this information, land managers can optimize their land management practices to mitigate particulate matter emissions and reduce exposure to dust.