Time-dependent local scour downstream of adverse stilling basin

The paper describes the evolution of local scour hole downstream of an adverse stilling basin. The research was conducted using a wide range of Froude number, sediment size, tailwater depth, length and slope of stilling basin. The maximum depth of scour and its distance from the stilling basin attained 87.5% in the first 24 hours and 86.3% when the experiment was continued for 54 hours. A power equation was adopted describe the characteristic dimensions of scour hole, time scale as well as geometry of stilling basin and sluice gate. The results showed a certain similarity among the scour profiles developed at different times. However, the shape of the holes was influenced with the change in length and slope of stilling basin. As the slope of stilling basin increased by 15%, the volume of sediment removed from the unit width of the hole, was increased by 30%.