Experimental study on the relationship between wind erosion rate and microtopography around tree-like vegetation

Abstract

Vegetation affects wind erosion rate and microtopography by modifying the near-surface airflow field, but the relationship between wind erosion rate and the characteristic parameters of microtopography remains unclear. In this paper, the wind erosion rate and microtopography around rigid tree-like plant models in staggered and square arrangements were measured in a wind tunnel. The results show that under the same plant density and incoming wind speed, the average wind erosion rate in staggered arrangement is 0.26–0.61 times higher than in square arrangement. The erosional distance upwind of plant, the width, depth and area of erosion pit increase with the increase of incoming wind speed and decrease with the increase of plant density. The width and area of pit increase linearly with the increase of erosional distance upwind of plant. The average wind erosion rate is significantly affected by microtopography and increases with the increase of standard deviation of change rate of microtopography height. The experiments found that there are two types of surface erosion around plants: local and global surface erosions. In local surface erosion, the average wind erosion rate increases with the increase of erosional distance upwind of plant, the depth, area and shape factor of pit.