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Submitted to: Encyclopedia of Water Science
Publication Type: Review Article Publication Acceptance Date: 9/13/2005 Publication Date: 3/27/2006 Citation: Van Pelt, R.S. 2006. Wind erosion and water resources. Encyclopedia of Water Science. 1(1). <http://www.dekker.com> 4 pp. Interpretive Summary: Fugitive dust is the most visible evidence of wind erosion. Dust may be transported hundreds or thousands of kilometers on the prevailing winds and affect water quality in watersheds far from the areas of origin. Dust neutralizes acid precipitation, adds nutrients and trace metals to watersheds, and often affects the color and turbidity of precipitation. It may also catalyze photochemical reactions in the atmosphere that affect the solubility of the trace metals. This review of dust effects on water resource quality was an invited entry to the Encyclopedia of Water Science Edited by Dr. Stanley Trimble (Taylor and Francis, New York). Technical Abstract: Wind erosion is the movement and loss of soil resulting from the interaction of a bare, loose, dry soil surface with wind. Although wind erosion occurs on all continents and in all climates it is most prevalent and its effects are most profound in arid and semi arid areas of the northern hemisphere. The most visible evidence of wind erosion is fugitive dust that may be entrained in global circulation patterns and transported hundreds or thousands of kilometers from the source. Global estimates of soil dust flux to the atmosphere range from 250 to 5000 Tg on an annual basis. Estimates of return flux to the surface of land areas range from less than 10 to more than 200 t km-2 yr-1 and estimates of total flux to the world’s oceans range from 532 to 851 Tg yearly. There remains a great deal of uncertainty as to the actual average quantities of dust involved in regional and global transport. Some of the dust returns to the earth by settling of larger particles from the atmosphere, but much more is scavenged by cloud formation and rainfall. Fugitive dust contains higher concentrations of organic carbon, basic cations such as Ca, Mg, and Na, plant nutrients such as N, P, K, and Fe, and numerous trace metals than the soils from which it was derived. These chemical species contained on dust, especially when hydrated, have been documented to react with and catalyze reactions with other atmospheric particulates, colloids, and gasses. Soil dust therefore has a great influence on rainfall chemistry and the chemistry of surface waters. This entry explores the many ways that atmospherically borne soil dust impacts the world’s water resources. |
