When waves approach the coastline they are refracted ,as the coastline is not a regular shape, and become parallel to the coastline.
Process of Wave Refraction
As each wave approaches the coast, it tends to drag in the shallow water which meets the headland. This increases the wave height and wave steepness and shortens the wavelength.
The part of the wave in deeper water moves forward faster, causing the wave to bend. The overall effect is that the wave energy becomes concentrated on the headland, causing greater erosion.
What does Wave Refraction cause?
The low energy waves spill into the bay, resulting in beach deposition. As the waves pile against the headland, there may be a slight local rise in sea level that results in a longshore current from the headland, moving some of the eroded material towards the bays and contributing to the build-up of the beaches.
