Study of Current- and Wave-Induced Sediment Transport in the Nowshahr Port Entrance Channel by Using Numerical Modeling and Field Measurements

Abstract

The Nowshahr port in the southern coastlines of the Caspian Sea is among the oldest northern ports of Iran, first commissioned in the year 1939. In recent years, this port has been faced with severe sedimentation issues in and around its entrance that has had negative impacts on the operability of the port. The present study aims at identifying major reasons for severe sedimentation in the port entrance. First, field measurements were evaluated to gain an in-depth view of the hydrodynamics of the study area. Numerical models then were calibrated and validated against existing field measurements. Results of numerical modeling indicated that wind-induced current is dominant in the Caspian Sea. The numerical results also indicated that in the case of an eastward current direction, the interaction between current and the western breakwater arm would lead to the formation of a separation zone and a recirculation zone to the east of the port entrance region. This eddying circulation could transport suspend settled sediments from eastern shoreline towards the port entrance and its access channel. The results of this paper are mostly based on the study of current patterns around the port in the storm conditions incorporate with the identification of sediment sources.