关键词: 戈壁风蚀面, 植被覆盖面, 粗糙度长度

Abstract: A physical model for determining the roughness length on gobi deflation plane and vegetated surface under different atmospheric stratification stability cases is developed based on the Monin-Obukhov similarity theory and the method of dimensional analysis. Then the relationship among the roughness length, the nature of the roughness units, the character of the passing wind and the atmospheric stratification stability parameter-the bulk Richardson number is studied through the model. The results show that the aerodynamic roughness length of gravel bed is a function of gravel size, coverage, free velocity, friction velocity and the atmospheric stratification stability; the roughness length of vegetation cover surface depends on the type, height, coverage of the vegetation, zero-plane displacement height, free velocity, friction velocity and the atmospheric stratification stability.

Key words: gobi deflation plane, vegetated surface, roughness length