GRADIENTS OF WAVE ENERGY AS THE MAIN FACTOR CONTROLLING THEEVOLUTION OF THE COAST OF RIO GRANDE DO SUL IN SOUTHERN BRAZILDURING THE LATE HOLOCENE

摘要

The 625 km long barrier coast of Rio Grande do Sul is gently undulating and consists of twornlarge subdued and relatively steeper seaward projections where stationary and receded barriers are found,rnand two landward low-gradient reentrances where prograded barriers occur. The type of barrier is relatedrnto wave energy, which in turn is controlled by processes of wave refraction and wave energy dissipationrnalong shelf gradients. This paper suggests that the alternation of contrasting types of barrier (prograded,rnstationary and receded) reflects the existence of a long-term gradient of wave energy along the coast of RiornGrande do Sul.