An analytical and field study on influence of breakwaters on beach morphological evolution: a case study (Astara Port)

Addressing the interaction of the presence of coastal structures, breakwaters for instance, and morphological changes is of great importance. The purpose of this paper is to investigate the influences of the extended breakwaters of Astara Port on sediment transport and beach morphological evolution in the vicinity of them so as to identify how the extension of breakwaters altered the sea bed topography. In order to describe evolving cross-shore profiles in the study area, beach profile surveys were conducted by a single-beam echo sounder. Results showed that the breakwaters considerably affected their surroundings, and scouring in front of them was obvious. Furthermore, comparisons of measured beach profiles with Dean's profile model for the equilibrium beach profile illustrated that the Dean's profile was not able to precisely represent the time- mean profiles. As a result, Dean's equilibrium profile was modified and a new model was developed so that it can represent more correctly cross-shore morphodynamics of the study area. The results revealed that modified equilibrium profile can be a better representative for the cross-shore profiles of the study area.