摘要: |
采用概化水槽试验研究了在不同植物间距、水流条件下,含淹没植被明渠水位、曼宁糙率系数的变化特征,给出了含淹没植被明渠的糙率经验公式.试验结果表明:相同的流量、水深条件下,明渠的水位壅高值和水面比降均随植物间距的减小而逐渐增大,当植物枝叶相互间贴近或交叉时,植物对明渠水位、比降的影响程度相对较大;水深基本相同、植物排列方式相同的情况下,随着流量的增加,水面比降基本呈线性增大趋势;水深相同的条件下,含淹没植被明渠糙率受水流流速的影响较小. |
关键词: 明渠 淹没植被 水位 比降 曼宁糙率系数 |
DOI: |
分类号:TV133 |
基金项目:水文水资源与水利工程科学国家重点实验室基本科研业务费重点项目(Y20809) |
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Variation characteristics of water level and roughness of an open channel with submerged vegetation |
JI Chang-hui, HONG Da-lin, DING Rui, SHEN Xia
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State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Nanjing Hydraulic Research Institute
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Abstract: |
Variation characteristics of water level and Manning roughness coefficients of an open channel with submerged vegetation are studied with flume experiments under different plant spacing and different flow conditions. An empirical formula for the Manning roughness coefficient of the open channel with submerged vegetation is obtained. The results show that the backwater and surface slope of the open channel increase with the decrease of plant spacing under the conditions of the same discharge and water depth. Influence of the submerged vegetation on the water level and surface slope is relatively larger when plant leaves touch or cross each other. Under the conditions of the same water depth and plant spacing, surface slope presents linear increases with the increase of flow. The influence of flow velocity on roughness of the open channel with the submerged vegetation is little under the same water depth. |
Key words: open channel submerged vegetation water level surface slope Manning roughness coefficient |