<p>Open channel non-uniform flows with various channel slope are more common in natural rivers and engineering. Variations in channel slope can affect turbulence structure, which in turn leads to changes in turbulence characteristics (turbulence intensity and Reynolds stress) in the vertical direction. Accurate understanding of turbulence characteristics allows prediction of pollutant transport paths and concentration distributions. Experiments with PIV measurements in open channel nonuniform flow with six channel slopes (0.005, 0.002, 0, -0.002, -0.006, and − 0.01) are used to analyze the variation of turbulence intensity and Reynolds stress distributions with channel slope, Reynolds number, and aspect ratio. The variation of shape parameters for these two distributions with pressure gradient parameters is further analyzed to improve the equations for turbulence intensity and Reynolds stress distributions. The equations are compared to the experimental data from this study and some reference data, and their predictions are more than 50% more accurate than other equations in the literature. In comparison to Townsend’s attached eddy model, the equations are more appropriate for turbulence in the outer regions. This is likely the result of a larger than expected eddy size in the outer region at high-Reynolds number condition. Furthermore, this study shows that the dip effect is exacerbated and extends into the fluid’s interior as bed slope decreases. Turbulence characteristic distributions are more susceptible to changes in non-uniformity on positive-slope and less susceptible on adverse-slope.</p>