Impact of Roughness Elements on Reducing the Shear Stress Acting on Soil Particles

Project summary:

Long-term erosion control of construction sites is dependent on vegetation reducing soil detachment by surface runoff. -Greater understanding of the detachment process is important in assessing the effectiveness of different vegetative -species and densities. Fundamentally, vegetal elements protect the soil by dividing the total shear of surface runoff -into components acting on the vegetation and the soil. This partitioning, however, is poorly understood. Research into-partitioning the total shear is currently being conducted for erosion control blankets. This study will extend this -work to consider roughness elements representative of vegetation. A theoretical model developed for wind erosion will -be used as the framework for studying vegetal impacts on shear partitioning. The overall goal of this project is to develop a better understanding of the interactions between overland flow, -vegetation, and erosion. This will be accomplished by 1) measuring the surface shear stress resulting from variations -in vegetal density, placement, and shape in a laboratory flume and 2) determining the effects of vegetation on reducing -surface shear stress over a range of overland flow conditions.