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Journal of Desert Research ›› 2019, Vol. 39 ›› Issue (5): 29-36.DOI: 10.7522/j.issn.1000-694X.2018.00095

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Influence of Vegetation Coverage on Sand Flow Structure and Wind Erosion Yield with Wind Tunnel Experiment as a Case

Yu Peidong1, Chen Yinping1, Li Yuqiang2, Yan Zhiqiang1, Wang Xuyang2,3, Niu Yayi2,3, Gong Xiangwen2,3   

  1. 1. School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China;
    2. Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China;
    3. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2018-09-15 Revised:2018-10-17 Online:2019-09-29 Published:2019-09-29

Abstract: Based on the sandy dunes with different vegetation cover in Horqin Sandy Land, the in-situ test was carried out by the movable wind tunnel in the field. In order to explore the quantitative relationship between the surface wind erosion yield and the wind speed and vegetation coverage, the effects of vegetation coverage on the sediment transport rate of sand flow were studied. The results showed that aerodynamic roughness changed with the increase of vegetation coverage, with firstly gentle and then steep trend, the correlation of them showed a cubic function growth; The sediment transport rate of each layer decreased with increasing height for each vegetation coverage, and increased with increasing wind speed; The wind erosion yield increased with increasing wind speed at the same vegetation coverage, and the correlation can be described by power function or quadratic function. Moreover, the quadratic function correlation was superior to the power function; At the same wind speed, the amount of wind erosion decreases stepwise with the increase of vegetation coverage, the wind erosion yield decreased gently with vegetation coverage less than 27%, when the coverage ranged from 27% to 43%, the wind erosion yield decreased sharply, and the wind erosion yield decreased slowly and tended to be stable when the coverage was over 43%; The relative interception rate decreased with the increase of wind speed, and increased with the increase of vegetation coverage. It would exhibit good wind and sand fixation effects when the coverage of the dune herbs more than 43%, the average relative interception rate reached 88.02%.

Key words: dunes, vegetation coverage, wind erosion, movable wind tunnel

CLC Number: