On wind and shear stress profiles above a change in surface roughness

The problem of determining the distribution of velocity and shear stress in the flow above a surface with an abrupt change in roughness is considered by using the ‘mixing‐length’ theory to relate the shear stress to the velocity profile and solving the resulting system of partial differential equations numerically. The results are compared with those obtained by Panofsky and Townsend (1964) and Taylor (1967), by assuming special forms for the velocity or shear stress profiles.