Analytical Understanding of Sediment Supply and Calibration on River Width Adjustment in Gravel Bed Rivers

An One of the hydraulic parameters which signify downstream hydraulic geometry is river width. In fact, river width is influenced by a number of parameters among which sediment load is important in gravel bed rivers. In this research, a large data base for the downstream hydraulic geometry of gravel bed rivers is examined by a nonlinear four variables regression analysis. The data base includes gravel bed rivers with meandering to braided in planform geometry. These data points consist of bankfull discharge, mean bed particle size, channel slope and channel width, which were used to predict sediment load transport from bed load and total load functions. Results indicate that the equation derived from regression analysis with four variables include mean bed particle size, channel slope, bankfull discharge and total sediment load transport per unit width of the channel performs better than other regression equations in estimating the channel width. Also, the appropriate total load function for estimating regime width of gravel bed rivers was suggested Engelund and Hansen (1972).