水土保持学报2017，Vol.31Issue(2)：50-56,78,8.DOI:10.13870/j.cnki.stbcxb.2017.02.010
模拟植被类型及空间配置对坡面流水动力学特性的影响
Effects of Simulated Vegetation Types and Spatial Patterns on Hydrodynamics of Overland Flow
摘要
Abstract
In order to systematically investigate the effects of vegetation types and spatial patterns on hydrodynamics of overland flow,this study was conducted to explore variations of hydrodynamic elements such as depth,velocity,flow regime and roughness through conducting a series of laboratory flume simulation experiments on smooth and vegetated beds under conditions of emerged flow,seven flow discharges,two vegetation types (flexible vegetation,rigid vegetation) and three vegetation spatial patterns at a gentle slope gradient of 1.4 ％.The results showed that:(1) In comparison with bare plot,mean flow depth increased by 1.4 to 2.8 times than bare plot and mean velocity was reduced by 31％ to 65 ％ with vegetation cover,while the combination of flexible vegetation and a banded pattern retarded overland flow best.(2) Flow index m indicated that the flow with rigid vegetation and checkerboard pattern had the roughest turbulence and index k,suggesting that the combination of rigid vegetation and the pattern of a single long strip parallel to slope direction exerted the most efficient influence on flow characteristics.(3) The flow regime was mainly transition state and was mainly controlled by the discharge.With the cover of vegetation,the flow pattern changed from supercritical flow to subcritical flow and was mainly influenced by vegetation patterns.(4) Mean friction coefficient (f) of the whole slope for vegetation treatment was 2.9 to 20.5 times higher than that of the bare slope,demonstrating that f increased more efficiently under subcritical flow.Emerged flexible vegetation with a banded pattern or a checkerboard pattern performed in a more efficient way than other vegetation distributions.While f alone slope distance under the banded pattern fluctuated,but the parameter kept stable with the checkerboard pattern under a better hydrodynamic condition.关键词
坡面流/柔性植被/刚性植被/植被格局/水动力学特性Key words
overland flow/flexible vegetation/rigid vegetation/vegetation patterns/hydrodynamics分类
农业科技引用本文复制引用
孟铖铖,张会兰,杨坪坪..模拟植被类型及空间配置对坡面流水动力学特性的影响[J].水土保持学报,2017,31(2):50-56,78,8.基金项目
国家自然科学基金项目(51309006) （51309006）
