Editing Soil erosion (section)

===Wind erosion===
[[File:Im Salar de Uyuni.jpg|thumb|[[Árbol de Piedra]], a rock formation in the [[Altiplano]], [[Bolivia]], sculpted by wind erosion]]
{{main|Aeolian processes}}
Wind erosion is a major [[geomorphological]] force, especially in [[arid]] and [[Semi-arid climate|semi-arid]] regions. It is also a major source of land degradation, evaporation, desertification, harmful airborne dust, and crop damage—especially after being increased far above natural rates by human activities such as [[deforestation]], [[urbanization]], and [[agriculture]].<ref>{{Cite book|author=Zheng, Xiaojing|author2=Huang, Ning|name-list-style=amp|title=Mechanics of Wind-Blown Sand Movements|publisher=Springer|year=2009|isbn=978-3-540-88253-4|pages=7–8|url=https://books.google.com/books?id=R6kYrbA3XSAC&pg=PA7}}</ref><ref>{{cite book|author=Cornelis, Wim S.|chapter=Hydroclimatology of wind erosion in arid and semi-arid environments|editor=D'Odorico, Paolo|editor2=Porporato, Amilcare|title=Dryland Ecohydrology|publisher=Springer|year=2006|isbn=978-1-4020-4261-4|page=141|chapter-url=https://books.google.com/books?id=rUsUPZbFHK8C&pg=PA141}}</ref>

Wind erosion is of two primary varieties: ''[[Aeolian processes#Wind erosion|deflation]]'', where the wind picks up and carries away loose particles; and ''[[Abrasion (geology)|abrasion]]'', where surfaces are worn down as they are struck by airborne particles carried by wind. Deflation is divided into three categories: (1) ''[[Downhill creep|surface creep]]'', where larger, heavier particles slide or roll along the ground; (2) ''[[Saltation (geology)|saltation]]'', where particles are lifted a short height into the air, and bounce and saltate across the surface of the soil; and (3) ''[[Suspension (chemistry)|suspension]]'', where very small and light particles are lifted into the air by the wind, and are often carried for long distances. Saltation is responsible for the majority (50–70%) of wind erosion, followed by suspension (30–40%), and then surface creep (5–25%).<ref>{{cite book|author=Blanco, Humberto|author2=Lal, Rattan|name-list-style=amp|chapter=Wind erosion|title=Principles of Soil Conservation and Management|publisher=Springer|year=2010|isbn=978-90-481-8529-0|pages=56–57|chapter-url=https://books.google.com/books?id=Wj3690PbDY0C&pg=PA57}}</ref><ref>{{Cite book|author=Balba, A. Monem|chapter=Desertification: Wind erosion|title=Management of Problem Soils in Arid Ecosystems|publisher=CRC Press|year=1995|isbn=978-0-87371-811-0|page=214|chapter-url=https://books.google.com/books?id=uS62XNzDZDsC&pg=PA214}}</ref> Silty soils tend to be the most affected by wind erosion; silt particles are relatively easily detached and carried away.<ref>Jefferson, I.F., Smalley>I.J. 1999. Saltating sand erodes metastable loess ground: events in the impact zone. https://infosys.ars.usda.gov/WindErosion/Symposium/proceedings/jefferso.pdf {{Webarchive|url=https://web.archive.org/web/20170211122659/https://infosys.ars.usda.gov/WindErosion/symposium/proceedings/jefferso.pdf |date=2017-02-11 }}</ref>

Wind erosion is much more severe in arid areas and during times of drought. For example, in the [[Great Plains]], it is estimated that soil loss due to wind erosion can be as much as 6100 times greater in drought years than in wet years.<ref>{{Cite book|author=Wiggs, Giles F.S.|chapter=Geomorphological hazards in drylands|editor=Thomas, David S.G.|title=Arid Zone Geomorphology: Process, Form and Change in Drylands|publisher=John Wiley & Sons|year=2011|isbn=978-0-470-71076-0|page=588|chapter-url=https://books.google.com/books?id=swz4rh4KaLYC&pg=PA588}}</ref>