The influence of combined vegetation stalk thickness on water flow resistance.

Vegetation that exists in the natural environment often involves a combination of plants with different stalk thicknesses. This combination affects the hydrodynamic properties of the ground surface, which in turn changes the velocity and distribution of run‐off. Current research on the influence of vegetation stalk thickness on water flow resistance is mostly focused on uniform vegetation. There have been few studies on the influence of non‐uniform vegetation on water flow resistance, and most have been qualitative in nature. In order to study the quantitative relationship between combinations of different stalk thicknesses and the water flow resistance of slope vegetation, a laboratory experiment was performed using a flume. The results show that when two different plant stalk thicknesses are staggered and combined, the diameters of the plants exhibit a power function relationship with the Darcy‐Weisbach resistance coefficient. When the diameter of the stem of one of the plants remains constant, at the same water depth, the coefficient of water flow resistance increases with the diameter of the stem of the other plant. Additionally, the coefficient of the vegetation flow resistance increases with increasing water depth. In the non‐submerged state, as the water depth increases, the rate at which the water flow resistance coefficient increases gradually declines, and as the diameter of any plant stem increases, the rate at which the water flow resistance coefficient increases also declines gradually. These findings provide a theoretical basis for the prevention and control of soil erosion and have important practical implications for maintaining water and soil resources. [ABSTRACT FROM AUTHOR]