Development of Equations for Meander Movement Velocities by SCE Optimization Algorithm based on Experimental Study

Abstract

Meandering rivers have a dynamic planform, which means that rivers move in radial direction with variable velocities. The movement velocities can be estimated from historical maps of specific river or using mathematical approach. There is not explicit method or suitable algebraic equation for estimation of river meander movement velocities. In this study, experiments were carried out in a laboratory flume, to develop novel equations to calculate meandering river movement velocities. We designated these empirical equations as the river resistance equations. The experiments were conducted with non-uniform, nonchosive sediment in a re-circulating flume with changeable slopes. The influence of bankfull discharge, bed slope and channel width on the meander movement velocities were discussed. Based on the experimental data, three novel empirical equations for prediction of Wx and Wexp and Wm were proposed. Moreover, the shuffled complex evolution (SCE) optimization algorithm was used to estimate the unknown parameters of the empirical equations. To validate SCE method, the result was compared with traditional multiple regression analysis. This comparison indicated that the SCE optimization algorithm outperformed the multiple regression analysis method in the empirical equations calibration.