摘要
为准确评估大范围绿洲防护林对上层气流动力速度的影响,利用动力平衡法推导上层气流相对动力速度的公式,并在4个不同结构网格进行实测估算,同时利用磴口荒漠生态定位站50 m通量塔风速数据拟合估算,得到4,5月大风时段防护林健全的绿洲区内部上层相对动力速度v'*约为1.3。分析绿洲防护林边缘区和内部上层动力速度变化的力学机制、防护林树高以下动力速度的构成因素,给出绿洲区地面阻力评价的方法,并以贴地层相对风速γ为目标参数构建大范围绿洲区防风效应评价的近似计算公式γ=v'*α(1/2)2l/[2α2l+(1-α2)A2]。阐述透风系数α、以树高倍数表示的林带间距l、树高的对数积分特征值A与林网区整体防风效应的关系。
The dynamic balance method was used to deduce the relative power formula of the upper air flow to accurately assess the impact of a wide range of oasis protection forest on the upper air power speed. Based on the measurement at four different geometric structure grids,and the fitting estimates with the wind speed data collected from a50 m flux tower at the Dengkou Desert Ecological Research Station,it was found the upper relative power speed during April and May gale periods within the oasis region was about 1. 3. The following formula was built to estimate the ground layer relative wind speed（ γ） and further to evaluate the effects of a wide range of oasis area on wind protection： γ = v＇＊α
出处
《林业科学》
EI
CAS
CSCD
北大核心
2013年第10期93-99,共7页
Scientia Silvae Sinicae
基金
"十二五"国家科技支撑计划项目(2012BAD16B0103)
"十一五"国家科技支撑计划重点项目(2006BAD26B0801)
关键词
农田防护林
相对风速
透风系数
林带间距
动力速度
farmland shelterbelts
relative wind speed
permeability of windbreaks
distance between main belts
power speed
