Results of the Sand Fixation Experiments in Mongolia
Dryland ecosystems,represented by steppe,desert landscapes,occupy 41.2％ of the total area of Mongolia. Hence, Mongolia is naturally sensitive to any desertification-driving factors such as climate change,draught and overgrazing (N. Sarantuya,1995,Ts. Adiyasuren,1992). One of the main indicators of desertification is quantification of the sand movement rate, and according to research results, sandy areas, which are widespread in the southern and western parts of Mongolia, are expanding rapidly as evidenced by increasing rates of sand shifting (D. Dash, 1999). The first experiments using mechanical barriers to prevent sand movement were conducted ? in Mongolia in the early 1980s by national scientists,Dr. Sainbayar and Kh. Jalbaa,where they trialed wooden fences. Later,from 2002,experiments using straw,stone and net checkerboards (20-22 cm in height) as well as clay barriers have implemented. For wind blown sands, the dense checkerboard pattern using stones can accumulate approximately 5-6cm depth of sand. Research results conducted over the last two years demonstrate that such kinds of dense barri-ers have to place on slopes of less than 5-10 degrees to be effective. Moreover,it is particularly effective for preventing sand shifting in corners of sand dunes rather than on the windward side of a slope. The capability of sand accumulation of the net barrier is not so dependent on hill slope; hence it can be used on windward side of sand dunes. The other types of such as stone and clay barriers are more efficient for protection of leeward sections of dunes. The height parameter for mechanical barriers in important,thus according to the short-term results we recommend to establish stone bar-riers with heights of 15-17 cm,clay with 20 cm,and net barriers more than 20 cm.
Sand fixation Mongolia Stone and clay barriers Net checkerboards barriers
N. Mandakh
Institute of Geoecology, Mongolia Academy of Sciences Baruun Selbe-15,Ulaanbaatar 211 238,Mongolia
国际会议
银川
英文
35-41
2006-06-20（万方平台首次上网日期，不代表论文的发表时间）