Combining surface mapping and process data to assess, predict, and manage dust emissions from natural and disturbed land surfaces

Abstract

The impact of dust emission on air quality is a significant health and environmental concern. Accurately determining the source (natural versus anthropogenic) and load of dust is an important component of any mitigation effort. We develop an approach to assess dust emission potential based on study of Nellis Dunes Recreation Area, a popular off-road vehicle area close to Las Vegas, Nevada. A mapping approach to assess dust emission potential is presented, which may serve as a template to assess other areas for this hazard. A 1:10,000 map delineating units based upon surficial characteristics affecting dust emission (e.g., soil texture, rock cover, surface crusts, and vegetation) was created. Seventeen surface units are grouped into four major classes (sand, silt and clay, rock covered, and active drainages). A >500 km network of trackways was digitized into a geographic information system (GIS) to determine the distribution of tracks across surface types to assess the density of disturbance. Wind-erosion measurements and off-road experiments using different vehicles (four-wheeler, motorcycle, and dune buggy) were performed on the various surface types to assess the amount of dust generated. Dust emission risk maps for Nellis Dunes Recreation Area are presented for two types of processes: off-road vehicular (ORV) activity and wind erosion. Highest dust emissions for ORV activity occur on map units composed of silt and clay, and on desert pavements. These areas can also produce large amounts of dust through natural wind erosion when disturbed. In contrast, the sandy units produce high emissions through natural wind erosion, and therefore limiting ORV use in those areas provides no benefit to air quality. © 2011 Geological Society of America.