Title: Anthropogenic Environments Authors
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: December 20, 2011
Publication Date: May 9, 2013
Citation: Zobeck, T.M., Baddock, M.C., Van Pelt, R.S. 2013. Anthropogenic Environments. In: Shroder, J.F., Lancaster, N., Sherman, D.J., Baas, A.C.W. Treatise on Geomorphology. Vol 11, Aeolian Geomorphology. San Diego, CA: Academic Press. p. 395-413. Technical Abstract: Aerosols or airborne dust can originate from sources unrelated to anthropogenic activity but may also be initiated or exacerbated by anthropogenic actions. Anthropogenic dust refers to dust activity (emission and suppression) that is present due to human activity. Wind erosion in the U.S. is a significant problem in agricultural mineral soils in irrigated arid and semiarid dryland farming regions and in some humid areas with very sandy or organic soils. Approximately 700 million metric tons of soils are eroded by wind in the U.S. annually. The principal anthropogenic factors affecting wind erosion relate to the soil surface and vegetation characteristics. Besides agricultural production and land drainage, wind erosion can also be accelerated due to fire, over-grazing, both potentially human-induced, and other anthropogenic activity. Wind erosion is accelerated after fire on erodible soils due to the great reduction in protective vegetation on the soil surface. Although agricultural and grazing lands, roads, recreational areas, and other land use contribute to the overall anthropogenic dust load, this chapter focuses mainly on wind erosion caused by agricultural activities. Perhaps the greatest surface stabilizing influence comes from vegetation and crop residues. Standing residues and growing crops provide greater protection than flat residues because they absorb much of the effects of the wind and thus keep it from impacting the soil surface. Tillage is used to prepare the soil for planting a crop, for weed control, to incorporate chemicals, to control erosion, and to disturb a surface crust in order to improve crop establishment, water infiltration, and erosion control. Wind erosion produces a number of environmental concerns that are discussed in the chapter. The often deleterious environmental effects of wind erosion may be divided most conveniently into on-site effects, those affecting the eroding soil surface and structures on and adjacent to the eroding surface, and offsite effects, those affecting environments at some distance from the eroding surface. Various wind erosion studies and methods to control wind erosion are also discussed. In areas where it is difficult to maintain adequate residue on the soil surface other practices such as emergency tillage may be employed. Tilling the surface in the direction perpendicular to the prevailing wind direction increases the aerodynamic roughness and provides micro-relief to protect a portion of the surface.