| Study on the aerodynamic roughness of grassland shrub belt |
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| DOI：10.7606/j.issn.1000-7601.2016.06.38 |
| Key Words: shrub belt degenerated grassland wind speed profile aerodynamic roughness |
| Author Name | Affiliation | | XUE Jing | College of Mechanical and Electrical Engineering, Inner Mongolia Agricultural University, Huhhot, Inner Mongolia 010018, China | | HOU Zhan-feng | College of Mechanical and Electrical Engineering, Inner Mongolia Agricultural University, Huhhot, Inner Mongolia 010018, China | | LIU Hai-yang | College of Mechanical and Electrical Engineering, Inner Mongolia Agricultural University, Huhhot, Inner Mongolia 010018, China | | YAN Jian-guo | College of Mechanical and Electrical Engineering, Inner Mongolia Agricultural University, Huhhot, Inner Mongolia 010018, China | | CHEN Zhi | College of Mechanical and Electrical Engineering, Inner Mongolia Agricultural University, Huhhot, Inner Mongolia 010018, China |
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| Abstract: |
| In order to carry out a quantitative research on the mechanism of repairing degraded grassland with shrub belt, the wind erosion sediment and wind speed profile with different heights of shrub belt and degenerated grassland had been collected by sand sampler and wind speed profiler. In addition, the corresponding aerodynamic roughness was calculated using the least squares method to calculate the wind profile data. The results showed that the protective mechanism of shrub for grassland was to enhance the aerodynamic roughness of earth surface and reduce the near-surface wind speed, leading to the improvement of ability to resist wind erosion of shrub compared to degraded grassland. A lot of aeolian deposits were concentrated in the near surface within the scope of 30 cm. Aerodynamic roughness appeared a trend of becoming declined with the farther distance from shrubs. At the same time, through studying shrubs of different heights, it was found that the aerodynamic roughness and the value of degraded grassland tended to agree with each other for shrubs with different heights of 0.3 m, 0.7 m and 1.5 m high when leeward sides were 3 m, 5 m and 6 m, respectively. The distance was an effective wind erosion area of shrub belt, and aerodynamic roughness and effective protective range became enlarged with the increase of the shrub height. This finding has a great significance for the repair of degraded grassland and a reasonable allocation of engineering dimension of shrub belt. |
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