Sand Transport in the Mojave Desert, by James King
The Sediment Transport to White-Margined Penstemon project investigates the potential pathways of nutrients that sustain and propagate the white-margined penstemon community. This species is found in the vicinity of several areas being studied within Southern Nevada and only two other locations in neighboring California and Arizona.
The project’s goals are to characterize the biological and physical features of the white-margined penstemon, its habitat, and how geomorphic processes can affect its sustainability. As Nevada has a large proportion of the land that the white-margined penstemon community occupies, it is the responsibility of land managers to protect it.
Within the Mojave Desert, sand transport by wind frequently follows distinct pathways (sand corridors) that can be compared to the path followed by a tributary stream as it makes its way toward a higher order primary river (Zimbelman et al., 1995). Typically in the Mojave, sand deposition occurs on the windward side of mountain ranges where sand ramps accumulate as the saltation process moves sand up the gentle windward slope of the ramps. It is likely that this type of sand transport system is operating within the identified areas of concern for the Penstemon albomarginatus (i.e., Hidden, Jean Lake, and Ivanpah, and Amargosa Valleys).
To characterize this type of sand transport system, a monitoring approach is proposed which will be undertaken by establishing seven measurement sites within the study area to characterize the regional wind flow in the area and the frequency and magnitude of sand transport events. Instrumentation to measure the important meteorological parameters (e.g., anemometers and wind vanes) will be placed at all of the monitoring sites. The instruments to measure sediment transport parameters will be state-of-the-art commercially available piezo-electric saltation sensors (Safires) that resolve the saltation activity in real-time and custom designed sand traps that collect sand for estimating the time-integrated mass flux. This network of instruments will collect data for quantifying the threshold winds for sand transport, the sediment flux from source areas to the respective downwind habitat areas, the frequency of these events, their temporal distribution, and relationships with climatic variables.
Research results will be used by both Clark County and the Bureau of Land Management as part of their environmental impact statement for the planning and construction of a new airport along the I-15 corridor. Along with other species habitat within the corridor, the EIS requires full inclusion of any potential impacts from any new construction.
This project compliments one of the research group’s general research objectives to understand vegetation dynamics in relation to sediment transport and dust emission controls. The group is currently seeking funding to extend this research by looking at the controls that solar faculties might have on reducing fugitive dust emissions if properly located, as they can act very similarly to vegetation to block the wind.
