Simulation and forecasting of downstream flow top width in a river reach using upstream flows

Abstract

In the present study, a modified Muskingum model incorporating flow and flow top width variables for a river reach and a system of reaches has been developed. The model assumes power form relationship between water discharge and flow top width at a section. The model is used to simulate and forecast flow top width on the basis of upstream flow(s) in Barak basin in India. Flow top width corresponding to different flow depths at the downstream section is estimated using DEM. Parameters in the proposed models are estimated applying NSGA-II. Model results are evaluated with standard statistical criteria. Application of the models show that for the estimated parameters, modified Muskingum models result to predicted downstream flow top width values that closely follow with the observed data. Results also indicate that the modified multiple inflows Muskingum model is more efficient and can be used with multiple upstream flows to simulate and forecast downstream flow top width in a river system.