摘要
以生态特征参数不同的植被群落为研究对象,在室内水槽中种植灌木、芦苇和灌木-草本植被混合群落,利用多普勒流速仪沿程测量各测点瞬时流速,基于河流动力学和紊流力学理论,将水流紊动强度表达为植被直径、水流绕流阻力因数、植被直径梯度和水流绕流阻力因数梯度的函数,比较不同类型植被群落之间水流紊动强度垂向分布规律的差异。结果表明,灌木完全淹没时,紊动强度在垂向上最大值位于灌木冠层顶端区域,极小值位于茎杆向冠层过渡区域。植被群落水流紊动强度垂向分布曲线上存在三个拐点,即茎杆向冠层过渡处、植被偏转点和植被冠层顶端。
The flow turbulence density through vegetation communities with different ecological characteristics were studied in a laboratory flume, in which, the shrubs, reeds and shrubs-grasses mixed community and shrubs-reeds mixed community included. The instantaneous velocity of each point was measured by the Doppler flow-meter. Based on river dynamics and turbulent mechanics theories, the turbulent density was expressed as the function of the vegetation diameter, the cylinder drag force factor, the gradient of the vegetation diameter and the gradient of the cylinder drag force iactor. The distributions among different vegetation community were compared. The results show that, while the shrubs are submerged, the maximum turbulence density is located at the top of the canopy and the minimum is in the zone from haulm to canopy, and there are three inflexion points in the distribution curve： the point from haulm to canopy, the vegetation deflect point and the point above the canopy top.
出处
《水力发电》
北大核心
2010年第10期3-6,15,共5页
Water Power
基金
国家自然科学基金资助项目(51009081)
国家杰出青年基金(50925932)
国家科技支撑计划(2009BAB29B09)
国家973重点基础研究发展计划(2006CB403304)
关键词
水流紊动强度垂向分布
植被群落
植被生态特征
vertical distribution of turbulence intensity
vegetation community
vegetation ecological characteristics
