模拟刚性植被盖度及配置方式对坡面流水动力参数及紊动特性的影响  

Simulation of the influence of rigid vegetation coverage and configuration on overland flow hydrodynamics and turbulence characteristics

作　　者：贺元 张会兰[1,2] 谷方正 王铃涵 李峰 He Yuan;Zhang Huilan;Gu Fangzheng;Wang Linghan;Li Feng(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Three Gorges Reservoir Area Forest Ecosystem Research Station in Jinyun of Chongqing,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]水土保持国家林业和草原局重点实验室北京林业大学水土保持学院,北京100083 [2]北京林业大学重庆缙云三峡库区森林生态系统国家定位观测研究站,北京100083

出　　处：《水土保持研究》2025年第3期8-17,共10页Research of Soil and Water Conservation

基　　金：国家自然科学基金项目“植被结构影响下的坡面流挟沙力动力机制研究”(52279056)。

摘　　要：[目的]揭示不同植被配置方式对坡面流水动力及其紊动特性的影响,为植被坡面土壤侵蚀机制和植被资源的合理配置提供科学依据。[方法]采用室内水槽冲刷试验的方法,模拟刚性植被近地表盖度(8.9%,4.5%,2.2%,1.1%,0.6%,0.3%)、乔灌配置方式(灌木、乔灌结合、乔木)与空间分布形式(均匀、随机、聚集)在6组不同流量条件下坡面流水动力参数、水流阻力的总体变化特征,并重点关注不同配置因子对坡面流影响程度的大小和局部尺度的促紊作用。[结果](1)植被覆盖使坡面相较于裸坡平均水深雍高了1.3~2.3倍,平均流速降低了16%~48%。不同植被配置方式壅水降速效果为密集>中等>稀疏、灌木>乔灌结合>乔木、随机>均匀>聚集,3种配置因子对坡面流的影响为植被盖度>乔灌配置>空间分布形式。(2)植被的体积阻力系数随着植被盖度的增大呈现线性增大趋势(R^(2)>0.90),且随流量增大,该趋势渐缓;紊流强度随综合植被配置参数的增大呈幂函数关系(R^(2)>0.99)。流速相同条件下,随着盖度增加,植被坡面相较于裸坡有产生尾涡增加紊动的作用;水力坡度相同条件下,植被坡面紊动能水平与裸坡相比,出现先增加后减小的变化特征。[结论]植被盖度对于坡面流阻力及紊动特性的影响要大于乔灌配置方式与空间分布形式。随着盖度增加,植被通过局部促紊作用与宏观增阻作用的相互制衡,共同决定了坡面流紊动能占总动能的比例。[Objective]This study aims to reveal the effects of different vegetation configurations on the hydrodynamics and turbulence characteristics of overland flow.The findings will provide a scientific basis for understanding slope soil erosion mechanisms and optimizing vegetation resource configuration on slopes.[Methods]This study used an indoor flume scouring experiment to simulate various near-surface coverage levels of rigid vegetation(8.9%,4.5%,2.2%,1.1%,0.6%,0.3%),arbor-shrub configurations(shrub only,arbor-shrub combined,and arbor only),and spatial distributions(homogeneous,random,and aggregated)at six sets of different flow rates.It analyzed overland flow hydrodynamic parameters(water depth,flow velocity,flow pattern,and flow regime),the overall changes in flow resistance,and focused on the influence degree of different configuration factors on overland flow and their turbulence-promotion effects at the local scale.[Results](1)Vegetation coverage increased the average water depth of the slope by 1.3~2.3 times and reduced the average flow velocity by 16%~48%compared to the bare slope.The effect of different vegetation configurations on water depth increase and velocity reduction followed the order:dense>medium>sparse,shrub only>arbor-shrub combined>arbor only,random>homogeneous>aggregated,and the effect of the three configurations on overland flow was vegetation coverage>arbor-shrub configuration>spatial distribution.(2)The bulk drag coefficient of the vegetated slope showed a linear increasing trend with the increase of vegetation coverage(R^(2)>0.90),and with the increase of flow rate,the trend was slower;the turbulence intensity showed a power function relationship with the increase of the comprehensive vegetation configuration parameter(R^(2)>0.99).Under the same conditions of flow velocity,with the increase of coverage,the vegetated slope had the effect of generating wake to increase turbulence compared with the bare slope.Under the same conditions of hydraulic gradient,the level of turbulent kinetic energ

关 键 词：坡面流 植被配置方式 模拟试验 水动力参数 紊动特性 

分 类 号：S157.1[农业科学—土壤学]