Influence of wave force direction on cliff profiles: formulation and observation in a case of horizontally layered cliffs in the northern coast of Gulf of Oman

Abstract

Many parameters can affect the profile of rocky coastlines. One of these parameters is wave orientation with respect to coastline direction which has been considered to be assessed mathematically in this study. Wave force can be resolved into two components, in a manner that one of them is perpendicular to the coastline. It was supposed that the perpendicular force of wave is responsible for hammer destroyer effect which makes cracks inside cliffs especially in parallel direction to coastline. Cliffs start to slide from these cracks and consequently the unstable slide zone increases. Hence, an inverse relation between the gradient of cliffs and perpendicular component of waves is expected. Perpendicular force, itself, depends on wave parameters and coastline direction with respect to coming wave orientation. Based on this conception, in this paper, a mathematical formulation was developed to correlate the wave orientation and the gradient of cliff on rocky coastlines. The conceptions and formulations were validated in horizontally layered cliffs in the northern coastline of Gulf of Oman.