Field Ovservation of Threshold Frictional Velocity on Different Types of Famland

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To quantize the difficulty level of dust production on the surface of different types of farmland,the Marticorena threshold frictional velocity pattern was used in this study to simulate the dust threshold frictional velocity.The results showed that the dust threshold frictional velocity of desertification farmland was 7.39cm/s,while it was 29.05 cm/s after the wheat harvested and the farmland ploughed; the turning green period was 46.85 cm/s; shooting period was 98.93 cm/s,the uncovered and the establishment period of fruit tree farmland was 26.0 and 139.15 cm/s.It was concluded that,bare desertification farmland could be changed into source of dust release easier. To quantize the difficulty level of dust production on the surface of different types of farmland, the Marticorena threshold frictional velocity pattern was used in this study to simulate the dust threshold frictional velocity. The results showed that the dust threshold frictional velocity of desertification farmland was 7.39 cm / s while it was 29.05 cm / s after the wheat harvested and the farmland ploughed; the turning green period was 46.85 cm / s; shooting period was 98.93 cm / s, the uncovered and the establishment period of fruit tree farmland was 26.0 and 139.15 cm / s .It was done that, bare desertification farmland could be changed into source of dust release easier.
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