Performance Evaluation of 2D Hydrodynamic Model for Lower Narmada River Basin, India

In the current study, a two-dimensional (2D) hydrodynamic (HD) model is developed to investigate the effect of proposed Bhadbhut Barrage on the hydraulics of lower Narmada River, India. The model has been developed for the river stretch of 63 km from Shuklatirth to the Arabian Sea at Gulf of Khambhat. The flood flow, routed from Garudeshwar gauging site to Shuklatirth (ungauged site) using the Muskingum channel (hydrological) routing method, is used as upstream boundary condition, whereas a constant (observed) high tide of 4.69 m above mean sea level is used as a downstream boundary condition in the model. The model is developed for the existing condition, for the flood of year 2006 by considering distributed floodplain roughness coefficient based on land use land cover (LULC) pattern. The performance of the developed model is found satisfactory, against the water level at Golden Bridge, Bharuch, with RMSE of 0.49 m. The calibrated model can be useful to simulate the different scenarios regarding the construction of barrage across lower Narmada River as well as the embankment along the channel and its effect of water level at different locations.