Experiment Study On Topsoil Aerodynamics Roughness Characteristics In The North Of Mount Yin

Aerodynamics roughness length is one of important indexes for estimating topsoil erosion. Through field experiments combining mechanics got aerodynamics roughness length of bare soil surface of the North of Mount Yin in winter and spring. The aerodynamics roughness length of farmland surface was different in winter and spring. The surface aerodynamic roughness length of winter is about 8~23.2 times more than spring's. Analysing the relationship between aerodynamic roughness length and physical properties of topsoil in farmland, some conclusions could be drawn from it. Then the physical indexes in the circumstances, water content of topsoil and aerodynamic roughness length was positive correlation. REG regression of SAS 8.2 were used to analyse the relationship among particles percentage of particles more than 2.0mm, particles between 0.05 and 0.5mm, and particles less than 0.05mm in topsoil with aerodynamic roughness length and get multiple linear regression model of particles percentage with aerodynamic roughness length. The model show particles percentage of particles more than 2.0mm in topsoil, which aerodynamic roughness length was positive correlation, particles percentage of particles less than 0.05mm in topsoil, which aerodynamic roughness length was negative correlation. Aerodynamic roughness length in spring is smaller than in winter's which provide conditions to spring fierce wind erosion. The large particles percentage of particles less than 0.05mm in farmland topsoil providing rich material basis to spring fierce wind erosion.Adapted numerical methods and Matlab Software simulated aerodynamic roughness length (ARL) and displacement height of grassland in Siziwangqi of Inner Mongolia. Surfaces including 8 vegetation densities and 6 vegetation height have been simulated. Through comparing the simulated results and field data, the simulated results could be a good reflection of the nature kinetic parameters. The study got some models, such as vegetation density, wind speed and friction speed model; vegetation density, wind speed and aerodynamic roughness length (ARL) model; vegetation height, wind speed and friction speed model; vegetation height, wind speed and aerodynamic roughness length (ARL) model.