*3.1. Turbulence Characteristics*

The distribution of the turbulent quantities, such as the sediment transport, is affected by the interaction between the bridge pier and flow. Chavan et al. [9,31] observed that the velocity and Reynolds stresses are negative upstream of the pier and close to bed, and downstream of the pier and close to the free surface, because of reversal flow, which causes a horseshoe vortex at the bed and a wake vortex at the free surface. In this paper, in order to deeply analyze the turbulent quantities and sediment transport around a bridge pier, upstream (U), downstream (D) and laterally against (S1 and S2) the pier, the distributions of the higher order moments (i.e., turbulence intensity and skewness), turbulent kinetic energy budget, and fluxes of turbulent kinetic energy, have been experimentally studied. In particular, as in the lateral sections, the turbulence quantities' distributions are similar [9]; hereafter, only the lateral section S1 will be considered, in order to avoid the repetition of results.
