前密后疏结构林带防风效应的风洞试验  

Wind Tunnel Experiment on Windbreak Efficiency of the Forest Belts with the Structures of Dense in Front Thin in Rear

作　　者：李亚琦 刘虎俊[1,2] 刘开琳[2] 万翔[2] 刘淑娟[2] 李学敏[2] LI Ya-qi;LIU Hu-jun;LIU Kai-lin;WAN Xiang;LIU Shu-juan;LI Xue-min(Gansu Agriculture University,Lanzhou 730070,Gansu,China;Desert Control Research Institute,Lanzhou 730070,Gansu,China)

机构地区：[1]甘肃农业大学,甘肃兰州730070 [2]甘肃省治沙研究所,甘肃兰州730070

出　　处：《西北林学院学报》2023年第2期126-131,共6页Journal of Northwest Forestry University

基　　金：甘肃省林草局项目:“低覆盖度非均匀配置防风固沙林防护效益的风洞实验研究”(ky19-03);甘肃省科技计划项目“河西走廊绿洲生态防护体系健康评价及精准修复技术研究与示范”(21ZD4FA010)共同资助。

摘　　要：通过2种非均匀结构林带对风速效应比较,探索低覆盖度的防护林结构模式,为干旱区防风固沙林建植提供参考。在风洞内布设覆盖度25%和30%的前密后疏结构的仿真防护林带,测定在6 m/s和10 m/s风速的林带水平与垂直方向风速,分析风场变化模式。结果表明,覆盖度30%林带与25%的防风效能差异不显著(P>0.05),相同覆盖度林前与林后的风速降低率差异显著(P<0.05)。覆盖度25%的防护林带对6 m/s风速降低率>10 m/s的分别有88.32%和80.52%的观测点的风速降低;有2个较为明显的减速区,林带前2倍树高,第1个林带的第1行与第2行之间区域,即距第1行之后1~2 H范围的风速降低最大。相同风速下,覆盖度25%的风速减速区较30%的面积大。覆盖度25%的林带降低风速率最大为83.38%,是覆盖度30%的风速降低率的1.11倍,25%覆盖度的前密后疏林带降低风速明显。适宜林带结构可提高低覆盖防护林效能。In order to explore the optimal structural modes of the forest belts with low plant coverage for wend-break and sand fixation,and to provide references for the construction of the belts,the windbreak efficiencies of two kinds of the shelterbelts with heterogeneous structures were measured.The simulated shelterbelts(25%and 30%in coverage)with the structures of dense in front and thin in rear were set up in a wind tunnel.The horizontal and vertical wind speed changes at 6 and 10 m/s were measured to analyze the windbreak efficiency.There was no significant difference between the shelterbelts with the coverage of 25%and 30%(P<0.05),but the wind speed variation rate of the 25%coverage was higher than that of the 30%coverage.The wind speed reduction rate of 6 m/s was greater than that of 10 m/s,and the wind speed of observation points decreased by 88.32%and 80.52%,respectively.There existed two obvious deceleration zones:the first one was located in front of the shelterbelt with the distance of two times of the tree height,and the second was one between the first and second row of the shelterbelt,that was 20-40 cm(1-2 H)after the first row,and the wind speed decreased the most.Under the same wind speed,the deceleration area of 25%coverage was larger than that of 30%.Suitable arrangement of forest belt can promote the windbreak efficacy for the belt with overage rate.

关 键 词：林带结构 仿真防护林 疏密结构 风速 防护效能 风洞实验 

分 类 号：S157.1[农业科学—土壤学]