低覆盖度下单个粗糙元保护作用的变化特征  

On Variation Character of Protecting Role of SingleRoughness Element in Low Coverage

作　　者：傅林涛 FU Lintao(School of Architecture and Civil Engineering,Chengdu University,Chengdu 610106,China)

机构地区：[1]成都大学建筑与土木工程学院,四川成都610106

出　　处：《成都大学学报（自然科学版）》2022年第4期423-431,共9页Journal of Chengdu University（Natural Science Edition）

基　　金：成都大学高层次人才培育项目(2081921086)。

摘　　要：圆柱体和长方体是地表风蚀相关研究中最常见的2种粗糙元.基于已有关于这2种粗糙元流向风速变化模型,推导了低覆盖度下均匀分布的单个粗糙元的保护区域最大流向长度、保护区域面积和保护效率的表达式,并考察和比较了采用这2种粗糙元时,这些物理量随面率和粗糙密度的变化规律.结果表明,随着粗糙密度的增加,单个粗糙元保护区域最大流向长度先增加后减小,最后逐渐趋于稳定;粗糙元保护效率随宽度呈单调减小后逐渐趋于稳定,而随着高度的增加呈现先增大后减小而后趋于稳定;相同面率和粗糙密度情况下,长方体粗糙元的保护效率比圆柱体粗糙元的更高.这些结果可为防治地表侵蚀提供理论指导.The circular cylinder and rectangular solid are two commonly used roughness elements in aeolian research.Based on the existing models of wind distribution around the two roughness elements,the maximum protecting length in stream-wise direction,protecting area,and protecting efficiency were theoretically derived for uniformly distributed roughness cases under low coverage conditions.The variations of these three physical quantities with area ratio and roughness density were evaluated and compared between the two roughness elements of different shapes.The research result reveals that the maximum protecting length increases firstly and then decreases gradually with the increase in roughness density.The protecting efficiency decreases gradually with the increase in roughness width,while it increases firstly and then decreases gradually with the increase in roughness height.Under identical area ratio and roughness density,rectangular solid elements have a higher protecting efficiency than circular cylinder elements.These results may provide theoretical guide for the control of erosion on the surface of earth.

关 键 词：面率 粗糙密度 最大保护长度 保护效率 保护面积 

分 类 号：X513[环境科学与工程—环境工程]