Performanceofgroynonthe Shoreline Changes

Erosion control in coastal areas, is imperative.Lian coastal area near the Bushehr nuclear power plant, which has a beautiful natural landscape, is being destroyed.The aim of this study is to evaluate the performance of groyn structures in the area.Using software MIKE21, Lian Shoreline is modeled. Trial and error method, groyn structures with different lengths in different areas of the site have been placed and sedimentation and erosion has been studied in each case.The results of this study indicate that the use of the groyn protecting the coastal beaches, if not done with careful study, can cause detrimental effects on downstream structures.The location of the groyn and the shoreline motion and position relative to each other, will affect on sedimentation and erosion and it’s volume.Modeling helps to choose the appropriate structures and it’s location for the site depending onareausage. For example, in point x=150 of the coastal line, after placing two groyn with length of 500 m, approximately 120 m of erosion will occur after 20 years.Although increasing the length of the breakwater to 850 meters, the erosion rate in this point reaches 23 meters. In point x=85 of the coastal line, after placing two groyn with length of 500 m, we have almost 275 meters deposition after 20 years. Although increasing the length of the breakwater to 850 meters, deposition will be 285 meters.