Numerical Method to Compute Water Surface Profile for Converging Compound Channel

Abstract

Water surface profile prediction is an important task in flood risk management in the urban area. In the present research, based on the principle of the momentum balance a numerical method is investigated to predict the water surface elevations in compound channels with converging floodplains. Experimental data series are collected from literature on converging compound channels for different geometry and flow conditions to test the present model. The developed method requires the percentage of flow in the main channel. To deal with it, various existing flow distributions model is used in the developed numerical method to estimate the water surface elevation. The flow distribution model which provides less error in water surface profile computation for converging part of the compound channel is selected. Finite difference method is used to solve the numerical model using MATLAB tool. The results obtained from the simulation show a good agreement with the experimental datasets. Statistical error analysis has been performed to verify the strength of the present model and the other prevailing water surface profile models. The present model found to provide the minimum error in terms of mean absolute error, mean absolute percentage error and root mean square error.