The endangerment of aeolian sand is one of the most serious eco-environmental problems facing the southern suburb of Beijing. To control wind erosion is thus a matter of great urgency. This paper chooses typical land-...The endangerment of aeolian sand is one of the most serious eco-environmental problems facing the southern suburb of Beijing. To control wind erosion is thus a matter of great urgency. This paper chooses typical land-use types, i.e., cultivated land, wild grassland, drifting sandy land, etc. based on the fixed experimental observation and quantitative analysis, to conduct studies on the principles and characteristics of aeolian activities and measures controlling wind erosion in Daxing District of Beijing, The results show that: the near ground wind velocity yielded the logarithmic distribution with height; there are significant differences among different ground cover roughness; there are significant differences in the corresponding friction velocities caused by different properties of the underlying surface; there are differences in the threshold wind velocities speed in different land .use types; and there are minus exponential relations between the sediment discharge percentage and the height at a range of 0-20 cm air flow layer, Different land use types result in various degrees of coarse component. There is a significant exponential relation between sediment transport concentration and wind velocity.展开更多
基金The national "Tenth-Five Year Plan" Key Program of Science and Technology, No.2002BA517A14 Beijing Sand Desertification and Wind Sand Countermeasure Demonstration Area Project, No.H020720110330 Key Project of Natural Science Foundation of Beijing, No.8011003
文摘The endangerment of aeolian sand is one of the most serious eco-environmental problems facing the southern suburb of Beijing. To control wind erosion is thus a matter of great urgency. This paper chooses typical land-use types, i.e., cultivated land, wild grassland, drifting sandy land, etc. based on the fixed experimental observation and quantitative analysis, to conduct studies on the principles and characteristics of aeolian activities and measures controlling wind erosion in Daxing District of Beijing, The results show that: the near ground wind velocity yielded the logarithmic distribution with height; there are significant differences among different ground cover roughness; there are significant differences in the corresponding friction velocities caused by different properties of the underlying surface; there are differences in the threshold wind velocities speed in different land .use types; and there are minus exponential relations between the sediment discharge percentage and the height at a range of 0-20 cm air flow layer, Different land use types result in various degrees of coarse component. There is a significant exponential relation between sediment transport concentration and wind velocity.