عنوان مقاله [English]
The entrance of ports, deltas and estuary are always subjected to wave attack, obstruction and erosion effects of th environment. The coastal structures of jetty type are erected to protect the facilities of importance and to increase safety of navigation. The contradictory effects of these structures on the environment are considered in this study and for the purpose of application, the Jetty Type structures for the marine environment of Kiashar Port on the North of Iran is selected in this paper.To investigate the effect of jetty structure on Kiashahr port of Guilan provience in Iran, Mike 21 software is used in this study. Wave heights are computed for port entrance for two distinct cases of prior and after the construction of jetty. It has been observed that the wave heights are reduced considerably for the port entrance after its completion. Further, due to the direction of jetty, the port is impressed by north east waves rather than the north-west waves. The wave height reduction is bounded between 0.15 to 1.2 m inside the protected coastal area. In total, the port entrance has more tranquility compared to the original condition. Finally the comparison of wave height of two modules of BW and NSW indicate that due to the refraction effect of port entrance, the results of wave height analysis for BW module are much higher than NSW module.