http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
宋在偶,朴晟植,勸度炫 弘益大學校 科學技術硏究所 2004 科學技術硏究論文集 Vol.15 No.-
In these days, it could be considered that the vegetation plays important roles of the stabilization of channel bed, as well as of habitats and feed for fauna. So, it has been studied important concern and study subjects that turbulent structure by vegetation, shear stress and transport as well as roughness and average velocity by vegetation. But From a hydraulic point of view, vegetation causes resistance to the flow and can increase the risk of flooding. Therefore, the purpose of this study is to investigate the flow characteristics due to vegetation densities in vegetated open channels through hydraulic model experiments. The velocity is logarithmically distributed from the upper part of vegetation to 0.8 of flow depth(h_(over)) over the vegetation deflected by the flow. The elevation(z_(0)) corresponding to zero velocity is calculated by using measured velocity profiles. In a vegetated open channel, z_(0) is 0.40 of mean height(h_(p)) of deflected vegetation. The roughness height is calculated by using velocity profiles and it is shown that the flow resistance tends to increase with the density of vegetation. The velocity profiles measured in a vegetated open channel is a relatively good agreement with those predicted from formulae proposed by Kouwen et al.(1969), Haber(1982) and El-Hakim et al.(1992).