Articles | Volume 17, issue 18
Atmos. Chem. Phys., 17, 11389–11401, 2017

Special issue: Anthropogenic dust and its climate impact

Atmos. Chem. Phys., 17, 11389–11401, 2017

Research article 26 Sep 2017

Research article | 26 Sep 2017

Anthropogenic dust emissions due to livestock trampling in a Mongolian temperate grassland

Erdenebayar Munkhtsetseg1, Masato Shinoda2, Masahide Ishizuka3, Masao Mikami4, Reiji Kimura5, and George Nikolich6 Erdenebayar Munkhtsetseg et al.
  • 1Meteorology, Hydrology and Permafrost Laboratory, National University of Mongolia, Ulaanbaatar, Mongolia
  • 2Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan
  • 3Kagawa University, Takamatsu, Japan
  • 4Meteorological Research Institute, Tsukuba, Japan
  • 5Arid Land Research Center, Tottori University, Tottori, Japan
  • 6Desert Research Institute, Nevada University, Las Vegas, USA

Abstract. Mongolian grasslands are a natural dust source region and they contribute to anthropogenic dust due to the long tradition of raising livestock there. Past decades of abrupt changes in a nomadic society necessitate a study on the effects of livestock trampling on dust emissions, so that research studies may help maintain a sustainable ecosystem and well-conditioned atmospheric environment. In this study, we conducted a mini wind tunnel experiment (using a PI-SWERL® device) to measure dust emissions fluxes from trampling (at three disturbance levels of livestock density, N) and zero trampling (natural as the background level) at test areas in a Mongolian temperate grassland. Moreover, we scaled anthropogenic dust emissions to natural dust emissions as a relative consequence of livestock trampling. We found a substantial increase in dust emissions due to livestock trampling. This effect of trampling on dust emissions was persistent throughout all wind friction velocities, u* (varying from 0.44 to 0.82 m s−1). Significantly higher dust loading occurs after a certain disturbance level has been reached by the livestock trampling. Our results suggest that both friction velocity (u*) and disturbance level of livestock density (N) have an enormous combinational effect on dust emissions from the trampling test surface. This means that the effect of livestock trampling on dust emissions can be seen or revealed when wind is strong. Our results also emphasize that better management for livestock allocation coupled with strategies to prevent anthropogenic dust loads are needed. However, there are many uncertainties and assumptions to be improved on in this study.

Short summary
Anthropogenic dust emissions induced by livestock trampling were measured using a mini wind tunnel device in Mongolian temperate grassland. A scale factor in dust emissions revealed an enhanced effect of trampling on dust emissions. The enhancement rate in dust emissions was enlarged by increased friction velocity. Our results emphasize that better livestock management is crucial to prevent dust loads by reducing the effect of trampling on dust emissions in dust seasons driven by strong winds.
Final-revised paper