Physical Modeling of the Scour Volume Upstream of a Slit Weir Using Uniform and Non-Uniform Mobile Beds

This study presents new laboratory data on the time-varying scour upstream of a slit weir used for sediment release near hydropower intake. The governing parameters in temporal and spatial hole development under steady unsteady flow conditions were experimentally investigated. includes 40 scenarios at center side weirs uniform non-uniform with median sizes d50 = 0.24, 0.55 mm four different intensities. steel built rectangular brick concrete flume dimensions 1.25 m wide, 8.0 long 1.0 deep. dimensional analysis supports recent studies. demonstrates an increment resulted volume fine sands about 2 times value coarse sand measured sands. However, was recorded as 2.5 that sand. There dramatic increase 4 3–3.5 when rate increased by times.