Experimental investigation on the erosion-deposition characteristics around isolated plants of different shapes in a wind tunnel

Abstract

• Plant shape has an important effect on the patterns of erosion and deposition. • The erosion and deposition areas around plant usually increase with blowing time. • Tree model has a larger erosion area than slender plant under similar frontal area. • Tree with short trunk and dense crown is better for sparse plant erosion control. Accurate description of the characteristics of erosion and deposition around single model plants of different shapes is important to evaluate the protective role of plants in wind erosion control. The variation of bed topography with time was measured in a wind tunnel for two flexible models and two rigid tree-like models. The bed surface height close to the plant decreases forming a deep well, while in the lee, a deposition area generally appears whose shape is affected by plant type. The local wind erosion rate on both sides usually decreases with time, and the deposition area in the lee with the local erosion rate less than zero gradually moves downwind with time while disappears for the tree-like plant model with a long trunk and a large crown. Under similar frontal areas of plants, both the erosion and deposition areas around the tree-like plant with a short trunk and conical crown, and the flexible plant with a large upper part and a small lower part are generally larger than that around the slender flexible plant. The rigid tree-like plant with a short trunk and a dense conical crown is better for erosion control due to the smallest net erosion rate and the erosion area similar to the deposition area, while the other plant models have larger net erosion rate and much larger erosion area.