Projects & Programs
Port Dhamra-Chandbali Overall Circulation and Sedimentation Study, International Seaports, Ltd., India
A hydrodynamic and sediment transport analysis was conducted in support of a feasibility study for a port construction project in Dhamra, Orissa, India. The proposed port is to be located at the mouth of the Dhamra River in the Bay of Bengal. The project consists of locating the port and the terminal along the mainland shoreline north of the Dhamra River mouth. This would require development and maintenance of a 19-kilometer-long navigation channel. Due to concerns over the potential for excessive sediment deposition from riverborne sediments, construction of a river training dike to eliminate Dhamra River flow into the navigation channel was proposed. The objectives of this study were to evaluate the feasibility of constructing the navigation channel and the proposed dike in terms of maintenance dredging requirements and oceanographic processes such as overall circulation and sediment transport. The proposed dike would alter the naturally maintained channel that carries nearly 50 percent of the Dhamra River flow and influence the distribution of sediments in the delta. PNNL staff
- Set up a lateral Two-Dimensional(2-D) finite element hydrodynamic model (RMA-2) for the entire study area, which included the Dhamra River inlet, proposed port location and the river delta. The hydrodynamic model was calibrated to existing conditions using field-measured currents.
- Set up and calibrated a sediment transport model (SED2D), that used the calculated currents as input and established baseline sediment transport conditions.
- Used the calibrated models to calculate the effect of proposed modifications (a 20-kilometer-long dredged channel, a turning basin and the presence of a dike across one of the main river channels) on the overall circulation and sedimentation patterns.
- Set up a hydraulic river model (HEC-RAS) over approximately 20 kilometers of the river to estimate the impact of the dike on the water surface elevations upstream from the mouth of the river.
The study results showed that construction of the new navigation channel and the port would likely not result in increased deposition of riverborne sediments. The new channel would function as well as, if not better than, the existing natural channel and would only require dredging in some parts. The study also showed that the proposed dike would not cause a backwater effect on the Dhamra River and that the project was feasible.
Project Highlights:
- Staff conducted a feasibility analysis using 2-D hydrodynamic and sediment transport modeling
- Modeling results showed that the proposed navigation channel would not lead to increased deposition of sediments
- The proposed dike alternative would not lead to significant backwater effects
- Staff demonstrated that maintenance dredging requirements would be acceptable and therefore concluded that the project was feasible.