Research Of Soil Wind Erosion In Zhundong Of Xinjiang

Wind erosion has a serious impact on the human living environment, is not conducive to the sustainable development of society, in order to prevent the expansion of desertification, scientists has carried out a large number of soil erosion related research. Xinjiang is located in the arid and semi- arid regions of Northwest China. The desertification of soil erosion has become one of the main environmental problems in the region, and the urgent need to reduce and control the spread of wind erosion. The opencast mining of East Junggar Basin in Xinjiang is one of the most serious soil erosion areas because of its arid climate and poor soil, there are also many artificial disturbance in recent years. This paper selects Xinjiang Zhun Dong opencast mine area as the study area, based on detailed field investigation and comprehensive laboratory analysis, the primary research of this paper concentrates mainly on the sand flow structure of sand source area, quantitatively estimate soil erosion and the establishment of suitable soil erosion risk model for the study area. Come to the following conclusion:（1） Sand flow structure characteristics in east of Gurbantünggüt desert was analyzed, results showed that 73.7%⁹7.9%of sand movement mainly in near-surface of the range of 0-40 cm., as the altitude（H） increases, the sand transport profile（Q） with a negative power function（Q=a×H-b） decrements; sand flow grain diameter size between 0.02¹mm, the main texture was fine sand（0.1-0.25mm） followed by medium sand（0.25-0.5mm）, the mean grain-size（M） which calculated by graphical method of Folk and Ward between 120²50μm, With the growth of height, the content of very fine sand increased, medium sand content reduced, the mean grain-size was showing a decreasing trend. Average saltation height of sand was positively correlated with wind speed,, maximum average saltation height can up 32 cm. The different of wind speed and local vegetation distribution caused the variation of sand flow structures and the change of wind direction also due to the difference of distribution of average saltation height between each sand traps.（2） Based on the profile distribution of ¹³⁷ Cs, ¹³⁷ Cs existed in 0-15 cm and 0-20 cm of soil in non-cultivated and cultivated land. In YN2, ¹³⁷ Cs distribution layer of ¹³⁷ Cs were quiet complete and showed negative exponential distribution curve, which can be regarded as an ideal sampling site of ¹³⁷ Cs background value. YN18 distribution in farmers ’ fields, which was farmland profile, exhibits irregular distribution of ¹³⁷ Cs and soil erosion rate was very low（0.240 t?hm-2?a-1） due to the effects of farming activities; YN19, due to its particular soil type, showed an erosion-deposition profile, thickness of accumulation was 0.016 m,whose erosion rate was 197.1 t?hm-2?a-1; YN7 and YN15 were typical soil eroded profiles, YN7 has highest erosion rate of sample point, thickness of erosion was 0.761 m, erosion rate was 10926.1 t?hm-2?a-1,YN15 due to its special land using type, surface small soil grain was easy occurred blow corrosion, so even has high of vegetation cover, soil profiles also was removed 0.378 m, erosion rate was 4392.9 t?hm-2?a-1; YN5 was fixed semi-fixed dunes, was a sedimentary profile, because of its terrain, accumulation of wind-sand all the year round, forming a special accumulation of landforms, thickness of accumulation was 0.187 cm, erosion rate was 2993.4 t?hm-2?a-1.（3） Based on wind erosion theories and GIS technologies, we built a wind erosion hazard degree model with impact factors as follows: the vegetation coverage, land use types, soil erodibility（K）, undulating terrains. Soil wind erosion risk of study area was is divided into 5 levels, no hazard, slight hazard, hazard, severe hazard, intense hazard. The erosion hazard degree of the study area was turned out to be serious with influences of varies factors, and the severe hazard became the main degree in the study area（14593.12km2（65.44%））, followed by slight hazard（5066.56km2（22.72%））, the other grades were less. Based on a GIS platform, we can conclude that there was an increasing trend of erosion hazard degrees from the south to the north and was patchy distributed in large scale.