Clear water scour at J-Hook Vanes in channel bends for stream restorations

J-Hook Vanes are in-stream river grade-control structures to reduce stress along the outside of the river bends and to promote scour in the pools and improving the aquatic habitat. The main purpose of this study is to investigate the effect of the channel curvature on the scour hole characteristics and morphologies downstream of J-Hook structures. The main scour geometry parameters have been analyzed at the hydraulic laboratory of the University of Pisa. Three different channel bends were studied. All experiments have been carried out in clear water conditions. Scour morphologies were surveyed using 3D laser technology. The results showed that an increase of the bend radius causes a decrease in the value of the maximum scour depth. The observations showed that the channel curvature is an important parameter to classify the scour morphology and directly affects the position of the maximum scour depth. Finally, different scour morphology types downstream of J-Hook Vanes are formed.