The effects of vegetation distribution pattern on overland flow

Abstract

Soil erosion is a major environmental problem. Vegetation, on the other hand, plays an important role in controlling soil erosion. The goal of the study is to examine the effects of the distribution pattern of vegetation on water flow. The vegetation parameters involved included the direction of plant rows, plant stem diameter and row spacing. To study how vegetation affects the flow of water on slopes, flume simulation experiments were conducted using three different plant row directions, three different plant diameters and three row spacing. Experimental slope is fixed, slope ratio of 1.0%. The hydraulic characteristics of the slope under the three vegetation distribution patterns are explored. The results showed that the pattern of vegetation distribution significantly affected the resistance of vegetation to water flow and pattern on this slope. When the angle (θ) between plant row and water flow directions decreased, the plant diameter (d) increased, or the row spacing (a × a) decreased, the Darcy–Weisbach resistance coefficient (f) for water flow became larger. Simultaneously, the Reynolds and Froude numbers (Re and Fr) both became smaller. In experimental procedure condition, the change rate of f, Re and Fr were analysed by linear regression, the θ decreased every 10°, the average increase rate of f was 6.6%, the average decrease rate of Re and Fr were 2.0 and 3.0%. The d increased every 0.001 m, the average increase rate of f was 41.6%, the average decrease rate of Re and Fr were 11.2 and 12.2%. The a × a decreased every 0.01 m, the average increase rate of f was 45.2%, the average decrease rate of Re and Fr were 11.7 and 10.7%. The flow depth h increased every 0.01 m, the average increase rate of f and Re were 13.6 and 25.2%, and the average decrease rate of Fr was 10.4%. The experimental procedure results will be valuable for not only revealing the hydraulic characteristics of flow over vegetation land, but also the optimisation of the distribution of vegetation on a slope.

Seed Removal due to Overland Flow on Abandoned Slopes in the Chinese Hilly Gullied Loess Plateau Region

“…Zhang et al . () noted that patches performed more effectively than strips in terms of increasing hydraulic roughness and then reducing soil erosion. Furthermore, plant shoots or stems can act as physical barriers while reducing the flow velocity of seeds transported through overland flows (Breshears et al ., ; Ludwig et al ., ).…”

“…Spatial patterns of vegetation are largely identified as patches or strips of shrubs and grasses that reflect limited water and nutrient availability in arid and semi-arid regions, and they influence the regulation of surface hydrological processes (Aguiar & Sala, 1994;Cerdà, 1997;Vásquez-Méndez et al, 2010). Zhang et al (2014) noted that patches performed more effectively than strips in terms of increasing hydraulic roughness and then reducing soil erosion. Furthermore, plant shoots or stems can act as physical barriers while reducing the flow velocity of seeds transported through overland flows (Breshears et al, 2003;Ludwig et al, 2005).…”

Simplification bias: lessons from laboratory and field experiments on flow through aquatic vegetation

“…Heterogeneous patches, where plant height varies within the array, create different flow patterns (Bai et al, 2015;Hamed et al, 2017;Horstman et al, 2018), and the layout of individual elements within the array (i.e. linear, staggered or random) can result in preferential flow paths (Etminan et al, 2017;Zhang et al 2018) that are not usually present within randomly distributed vegetation patches in the field. The choice of relevant parameters and length scales to be represented in laboratory studies depends on the focus of the study itself, and has been a topic of discussion among researchers (e.g.…”

Effects of Vegetation Pattern and Spontaneous Succession on Remediation of Potential Toxic Metal-Polluted Soil in Mine Dumps

“…Therefore, the growth and quantity of remediation vegetation affects the potential toxic metal remediation of soil in the two different vegetation patterns investigated in this study. Moreover, vegetation pattern affects the surface runoff and influences the soil erosion [46]. After years of developing sloping farmland, the rainfall receptivity and soil microbial community diversity of the farmland could be effectively improved [47].…”