چكيده به لاتين
Abstract:
Coastal erosion is one of the most crucial factors that damage the northern coast of our country. The main cause of coastal erosion is the disruption of natural conditions due to port construction and longshore sediment transport. The coast of Amir-Abad in Mazandaran province is out of equilibrium and hydrodynamic stability caused by construction of the Amir-Abad port, so that the drastic erosion is observed in the eastern side of the port. In order to prevent erosion in this area of the port, a sea wall has been built which also causes more erosion at the the end part of this wall.
The aim of this research is to simulate the hydraulic and sediment transport processes in the mentioned-above part of the port and represent proper solutions to prevent erosion in this area. For this purpose, MIKE-21 software package is used to simulate alternative solutions to confront erosion in the eastern coast of Amir-Abad port and finally, four plans have been presented for confronting erosion in the intended area. First, by using the SW and HD module, pattern of coastal waves and flows have been studied, respectively, to simulate the hydrodynamic of the model area. Then, by using the ST module of MIKE-21 software package, the way of longshore sediment transport in the aforesaid coast has been studied. At last, with accurate study of simulation cases, suitable structural solutions were designed to prevent erosion in the eastern coast of Amir Abad port and the results of the proposed solutions were analyzed by the use of the software package. The simulation results indicate that the dynamical equilibrium solution yields the least amount of sediment accumulation for the target area in one year, and the second solution which is using the groin and static equilibrium model, respectively, accumulate more sediment over a year. But the combination solution, which is using the groin structure and the static equilibrium, simultaneously, achieves the desired result in the shortest time. On the other hand, using the collective groins solution will have the least cost due to the fact that in this solution there is no need for beach nourishment.
Keywords: Coastal erosion, shore protection structures, beach nourishment, Amirabad port, MIKE 21
