The Effect of the Permeable and Impermeable Spur Dikes on the Morphology of the Bed

Abstract

Flow becomes more complicated in meandering and natural channel which leads the researchers to focus on the observations of natural and laboratory channels to study the characteristics and hydraulics flow in meandering channel. Three cases for installing impermeable and permeable spur dike with 30o in the entrance of meandering channel (left side, right side and both sides of channel) are used in this study using four levels of discharge (24.096, 27.477, 31.016, 34.71) l/sec for each case. The study concluded that the permeable spur dike reduced the amount of erosion and deposition in the meandering channel and maximum deposition (18.2cm) occurred in the case of impermeable spur dike on both side of channel at 2.5m from the beginning of the curvature of meandering channel and at biggest discharge (34.71) l/sec. The results of experiments showed that the minimum erosion (9cm) occurred in the case of permeable spur dike on right side of channel at 0.3m from the beginning of the curvature of meandering channel and at biggest discharge (34.71) l/sec where the impermeable spur dike has reduced the maximum depth of engraving by (10)%.