Hydraulic jump is one of the important phenomena in open channels and there is a turbulence and twisting in water from the beginning to the end of it. The flow change from the supercritical to the subcritical state is accompanied by a large amount of energy. Hydraulic jumps are used to reduce this energy. In order to reduce the damage caused by hydraulic jumps, structures such as a stilling pools are immediately used after gates or downstream of the weirs. Hydraulic jumps may occur on smooth or sloping surfaces. Many research has been done to economize the stilling basins. In recent years, it has been found that the presence of roughness or slope in the bottom of the basins can be effective in reducing jump dimensions. In this research, changes in hydraulic jump characteristics on trapezoidal roughness and adverse slope have been investigated. Experiments were carried out in a rectangular flume of length 8, width 0.4 and height 0.6 m. In order to create a hydraulic jump a sluice gate was used at the beginning of the channel. A total of 135 experiments were conducted in the range of 4 to 9 Froud numbers. The conjugate depths was measured by limnometer and velocity profiles was measured by pilot tube. In this study, at the bottom of the stilling basins there are piezometers with a spacing of 5 cm apart. The results showed that the secondary depth of the jump was reduced by 18.8% compared to the Key words Hydraulic jump, Trapezoidal roughness, Adverse slope, Secondary depth, Jumping length, Roller length, Energy loss, Cavitation Top of Form Bottom of Form
