Influence of Roughness Density and Plant Distribution on Wind Flow Patterns within a Complex Vegetated Surface
This thesis investigated the interaction of complex vegetation with wind flow and sediment transport at a creosote shrubland located in New Mexico and formed part of a larger on-going study to improve wind erosion modeling techniques. Directionally dependent roughness densities, λ, were computed and compared to mean wind speed ratios (WSRs) derived from anemometry data. A significant relationship existed among decreasing WSRs and increasing λ, indicating that shelter to the ground changed depending on the orientation of the wind. WSRs were larger on the west, more sparsely vegetated side, than in the east, demonstrating that distribution and plant size have a significant effect on near surface winds. Comparison of these data to a similar study completed in a mesquite coppice dune field demonstrated weaknesses in the roughness density parameter. These results have application for improving the understanding of interactions between wind flow and vegetation in complex rangeland environments.