Eolian sediments generated by anthropogenic disturbance of playas: human impacts on the geomorphic system and geomorphic impacts on the human system

• Published in: Geomorphology (Amsterdam) Vol. 17; no. 1; pp. 207 - 228
• Main Author: Gill, Thomas E.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-09-1996; Elsevier
• Subjects: Bgi / Prodig; Biogeography; Earth sciences; Earth, ocean, space; Ecosystems and biological productivity; Exact sciences and technology; Marine and continental quaternary; Physical geography; Surficial geology; Middle East; Asia; United States; Australasia; Africa; California; Australia; North America; Mesozoic; Quaternary; ground water; arid environment; reactivation; climate; clastic sediments; human activity; surface water; sedimentary rocks; drainage basins; suspended materials; Triassic; Eolian transport; winds; climate effects; global change; playas; eolian features; drainage; lakes; particles; semi-arid environment; dust; Human impact; Arid area; Water use; Semi-arid area; Lake; Atmospheric pollution; Aeolian features; Groundwater; Wind erosion; Environmental degradation; Ecosystem; Aeolian dust; Aeolian transport
• ISSN: 0169-555X; 1872-695X
• DOI: 10.1016/0169-555X(95)00104-D

In many of the Earth's arid and semiarid lands, saline lakes, playas, and similar landforms are disturbed as a result of human activity. Diversion and/or consumptive use of surface or groundwaters has created the effect of a climate change in numerous drainage basins, resulting in the desiccation of lakes and reactivation of eolian processes at many locations. Playas are natural sites for extensive eolian activity because of the deposition of clastic and chemical sediments in basins by surface water (via fluvial transport) and groundwater (via efflorescence). Wind erosion and deposition of playa sediments has had a major role in the development of landforms and sedimentary units in the present (lunette fields worldwide; Simpson Desert, Australia) and geological past, from the Triassic (Mercia Mudstone, England) to the Quaternary (Lahontan Basin and Cima Volcanic Field, USA).
Anthropogenic disturbance or desiccation of playa systems has resulted in the eolian transport of sand (e.g. Lop Nor, China; Konya Basin, Turkey; Rajasthan, India; Kappakoola, Australia; several sites in West Africa) and/or dust (e.g. Aral Sea, Kazakhstan/Uzbekistan; Old Wives Lake, Canada; Kara Bogaz Gol, (ex-)USSR; Lake Texcoco, Mexico; Owens (dry) Lake, Mono Lake and other playas, USA). Typically, this is accomplished by abstraction of water and/or removal of vegetation from terminal lake basins. An extensive review of the literature documents many examples and/or potential examples of such phenomena in numerous nations. The reactivation of eolian processes from closed basins produces air pollution in the form of fugitive dust (naturally occurring compounds released into the atmosphere by human actions), and has significant environmental and economic impacts on human activities in the surrounding areas. Restoration or mitigation of degraded land on or surrounding playas has been accomplished at Lake Texcoco, Kara Bogaz Gol and the Konya Basin, and is being actively implemented at Mono Lake, Owens (dry) Lake and the Aral Sea.