A convolution method is developed for computing the bottom stress in a vertically integrated hydrodynamic numerical model. By this means the bottom stress is no longer related to the depth mean current as in a ''conventional'' vertically integrated model, and an enhanced representation of the bottom stress is possible (an ''enhanced'' vertically integrated model). Consequently, the enhanced model can reproduce phase lags and differences in direction between bed stress and depth mean current, which cannot be taken into account in conventional vertically integrated models. A linear of quadratic frictional formulation can be used with the method. Idealized calculations of wind-induced flow in a rectangular basin show that the bed stress computed by the convolution method is in full three-dimensional model. However, significant differences in the bed stress between the three-dimensional and conventional two-dimensional model are evident. Also in this paper, a method is developed for extracting current profiles from vertically integrated models. Current profiles extracted from the enhanced two-dimensional model, for a range of frictional effects, are found to be in good agreement with those computed using a full three-dimensional model. ¿ American Geophysical Union 1988