DESIGN OF AN OFFSHORE PORT BASED ON COASTAL SEDIMENT AND ENVIRONMENTAL ASPECTS

Sand deposition at the port entrance and erosion along the down-drift side of the port are the most important points to be taken into consideration for designing the layout of small fishing ports constructed on sandy beaches [1]. Breakwaters trap sediment moving along the coast, and at least in the first year after construction of the port, no (or hardly any) sediment will pass the breakwater and serious erosion may occurs at this side of the fishing port. On the other hand, sediment will deposit just after the construction of the port at the up-drift side and sand deposition at the approach channel and at the entrance of the port will occur [2]. Cage culture is one the most commonly used methods which recently has been considered for fish farming in many countries. In this regard, Iran Fisheries Organization has a plan to develop fish cage cultures at some locations in the Caspian Sea. Larim site which is located at the 30km east of the Babolsar port is one of these selected locations. Marine section of each site is going to have two main parts: 1- An offshore part including cage, feeding barge, … and 2- An onshore port which supports the service and feeding vessels. Many small ports constructed along the southern coasts of the Caspian Sea suffer from different modes of sediment problems. An offshore port connected to the shore by an open bridge which doesn t block the littoral drift and so could be proposed as an alternative for connected small nearshore ports and a solution for relative sediment problems. The purpose of this study is to propose an offshore port layout to reduce the sedimentation problems for the Larim service port located in Mazandaran province, north of Iran. service port located in Mazandaran province, north of Iran. To achieve this goal, a series of numerical modeling of waves, currents, sediment transport and coastline evolution have been conducted by LITPACK and Mike21 for 1D and 2D simulation respectively. Also the functional design and dimensional ratios of main parts have been controlled by the relative design references advice.