Barrier island

Abstract

Morphogenesis and evolution of barrier islands are complicated processes. It is clear that the formation of a barrier island is the result of multiple processes and no simple hierarchical relationship can be deduced among the processes in influencing barrier island development. Among different processes that may affect the morphological development of a barrier island, some are found to be of critical importance and act as universal boundary constraints. The history of tectonics and eustatic sea-level change seems largely to determine whether a barrier island can be formed. With favorable tectonics and sea-level change for barrier island formation, a combination of shoreface slope, wave-tide regime, and sediment source determines how a barrier island is formed. Wind-wave climate, as well as the rate and composition of sediment supply, subsequently affects the migration and development of the island. In most areas, vegetation properties (e.g., species, coverage) are important in shaping the island morphology. In areas with a thick and compressible substrate, local consolidation through self-loading of underlying substrate also plays a role in barrier island evolution. Numerical modeling provides a way to quantify the effects of different processes on barrier island morphogenesis and evolution. However, one should always be aware of the limitations when constructing a model for a specific research object, and simulation results should be carefully interpreted. Much progress is still needed to develop robust models for better understanding of the origin and development of barrier islands.