Study on Influence of Non-submerged Rigid Vegetation Array Spacing on Surface Water Flow

Artificial planting vegetation can slow down water erosion and promote material deposition, which has the significance of ecological civilization construction. In order to explore the effect of vegetation array spacing on flow pattern and hydraulic characteristics in surface water flow, a non-submerged rigid vegetation hydraulics model with 5% coverage (210 plants) was established based on the actual situation. The vegetation with the ratio of the width of the vegetation area d to the width of the gap area D of 1 was evenly arranged as the control group, and the d/D was 0.625,0.401,0.25,0.142 and 0.0626 as the experimental group. Based on the experimental analysis and Fluent numerical simulation, the vegetation with the same coverage is analyzed as the width of the vegetation area becomes larger and larger, that is, the vegetation arrangement tends to be uniform, the results showed : Frictional head loss along the way and Darcy-Weisbach resistance coefficient increase, water blocking effect is obvious; under the influence of water depth, the flow velocity decreases and the Reynolds stress increases in the lower half of water depth; surface velocity decreases and turbulent kinetic energy increases on non-submerged vegetation; water blocking effect of vegetation zone is better than gap zone. It consumes water energy to achieve water blocking effect and prevents the surface of water flow from being excessively washed, which has certain value for flood control and disaster reduction.