The present study describes the methods of bed shear stress estimation, numerical estimate of velocity distribution and quadrant events on different hydraulic roughness. Quadrant events of velocity signify the contribution of velocity to generate shear. Experimental data sets of velocities were collected over bed with different hydraulic roughness. In the present work, a turbulent kinetic energy method is anticipated as more reliable to describe the bed shear stress in open channels. These data analysis express that the quadrant events associated with flow is influenced inherently by the bed roughness. Percentage distribution of first and fourth quadrant looks like a wine cup which is wider in the case of hydraulically smooth conditions and getting narrower as the bed roughness increased. It is also a sign of increasing randomness throughout the depth with increased roughness. It is found that at same relative depth for three different roughness conditions, eddy motions are displaying more uncertainty for hydraulically rough condition. Increase in bed roughness augments randomness of Reynolds stress at relative depth 0.05-0.4. The analysis relies on relative depth, which can for imply the local phenomenon and this local phenomenon of velocity on different bed roughness condition was also investigated in this paper. © 2015 Indian Society for Hydraulics.