Effects of sparse rigid stem vegetation coverage on hydrodynamic characteristics of overland flow in a gentle slope area

Abstract

Vegetation plays a vital role in natural ecosystems, especially in soil and water conservation. The accurate estimation of hydraulic parameters of overland flow is an important means to understand the hydraulic characteristics of overland flow and soil erosion. However, there is limited research on sparse stem vegetation coverage under gentle slope conditions. This study aims to understand the inherent laws that control overland flow structure under sparse vegetation cover. To achieve this, hydraulic characteristics of surface runoff on slopes covered by stem vegetation were quantified for seven flow discharges (Q) (0.0313-0.5203 m 3 /min), four slopes (S) (0.0-3.0%), and six stem coverage degrees (Cr) (0.07-0.72%) through a laboratory flume. The results showed that the same impact factor has different degrees of influence on different hydraulic parameters of overland flow resulting in varied hydrodynamic characteristics. In this study, for the vegetation coverage of sparse stems, under the condition of the flat slope, Cr is the dominant factor affecting Froude number and Manning roughness coefficient, whereas Q is the dominant factor affecting flow velocity and Reynolds number. However, under the condition of the non-flat slope, Cr is the dominant factor affecting Manning roughness coefficient, Q is the dominant factor affecting Reynolds number, and S is the dominant factor affecting the velocity and Froude number.

Research on the Impact of Using a Combination of Rigid and Flexible Vegetation on Slope Hydrological Properties in Loess Regions

“…Slope flow is a thin layer of water that flows along the surface of a slope due to gravity after snowmelt, rainfall, and losses such as infiltration, depression filling, and vegetation interception [3]. It plays a crucial role in slope erosion and sedimentation processes [4], and its hydraulic characteristics directly affect the intensity of slope erosion and its spatial distribution characteristics [5]. However, the hydraulic characteristics of slope flow are, in turn, mainly influenced by factors such as vegetation cover, slope, and flow rate.…”