Effect of Longitudinal and Side Slope of Flood Plain on Sediment Erosion in Compound Channel

The study of floods has always been important for researchers due to the great loss of life and property. Investigation of flood bed can provide appropriate solutions to reduce this phenomenon to managers and researchers. In this research, the compound channel (with flood plain on one side of the main channel) Been paid, Therefore, two experimental models of compound channel in laboratory flume were examined by considering dimensional analysis. With the goal Investigation of lateral slope of flood wall in laboratory model In the first model, transverse slope 0 And in the second model, a value equal to 50% Was considered. Also in order to investigate the effect of longitudinal slope of river bed sediments Longitudinal slope in three steps 0.00 2, 0.004 and 0.006 Was changed. Examining the ADV speedometer data, the results showed that with increasing the longitudinal and transverse slope (slope of the flood wall) of the channel, the maximum longitudinal velocity changes to the floor of the channel. In order to investigate the effect of average sediment diameter on the scouring process during experiments Mm was used. The results showed that increasing the longitudinal and transverse slope had a great effect on increasing the volume of washed sediments 3 and 0.9 of sandy sediments with a diameter Along the canal and with the increase of these longitudinal and transverse slopes in the channel, more sediment transport volume occurs. In the following, using Investigation of dimensionless numbers obtained from dimensional analysis, dimensionless weight landing number was introduced to evaluate this value value of other hydraulic parameters and Was introduced. A relationship based on nonlinear regression with correlation coefficient Acceptable was introduced at around 0.88.