凸型坡面植被空间配置调控坡面流水动力学特性的机制OA

[Objective]This study aims to determine the optimal location of vegetation belts for preventing soil erosion on convex slopes in the Loess Plateau,clarify how the coupling between slope morphology and vegetation layout regulates surface runoff hydrodynamics,and provide theoretical support for optimizing vegetation configurations in soil and water conservation practices.[Methods]An indoor flume experiment was conducted using three convex slopes with curvature radii of r1=6.1951 m,r2=9.2301 m,and r3=18.3853 m,and a flat slope as the control.Under five conditions of single-width flow rates of 3.1,4.2,5.3,6.4 and 7.5 L/(m·s),the hydrodynamic characteristics were systematically observed at different vegetation belt locations:the upper part of the slope(L1),the middle and upper part of the slope(L2),the middle part of the slope(L3),the middle and lower part of the slope(L4)and the lower part of the slope(L5).[Results](1)Vegetation cover significantly changed the overland flow regime.Compared with bare slopes,water level increased by 0.93～1.35 times,while flow velocity decreased by 2.6%～27.5%.On convex slopes,water depth along the longitudinal direction showed a nonlinear distribution pattern of first decreasing and then increasing,with a maximum decrease of 83.2%,and spatial heterogeneity was significantly higher than that on flat slopes.(2)The Reynolds number(Re)showed a strong positive linear correlation with flow rate(R2>0.99),but the influence of slope shape was not significant.Vegetation belts increased the resistance coefficient(f),promoting a transition to a tranquil flow regime.f and Re followed a power function relationship(R2>0.82).(3)Vegetation belt location influenced flow velocity regulation with significant spatial heterogeneity(p<0.01).Under flat slope conditions,the vegetation belt at L2 location showed the best deceleration effect,while on convex slopes,the L4 location exhibited the highest flow deceleration rate,with a maximum delay rate of 27.5%.[Conclusion]On convex slopes of the Loess Plateau,placing vegetation belts at the middle and lower part of the slope(L4)can significantly improve soil and water conservation effectiveness.Slope curvature can alter the distribution of flow potential energy along the slope,thereby strengthening the flow resistance effect of the vegetation belts.In practical applications,the location of vegetation belts should be optimized based on topographic characteristics.