impact of groyne construction on beach; case study anzali & astara coasts

 the groyne is an important sea engineering adopted much to protect beaches and the silt project in the present coast of many countries. the object of construction a groyne or groyne system is to stabilize a stretch of beach against erosion where that erosion is due primarily to a net alongshore loss of sand. the design and construction of groins requires the services of a professional engineer and a contractor to construct the coastal protective structures, it is necessary to estimate the scouring depth and bed level changing in the vicinity of such structures. due to the construction on the caspian sea coastals especially anzali and astara beaches in the gilan province, which are used as commercial banks and recreational beaches, groynes application can have an important role in stabilizing these beaches. first in the article the groyne impact on beach was investigated, however design criteria in to other coastal's books has been observed, the scour criteria at this structure is paid less. at the end of the paper to the scour risk of anzali and astara coast predicted, considering the results found scour risk of anzali coast be observed to a greater degree.