Investigation of shoreline recession at Amity Point, North Stradbroke Island.

The Amity Point region on North Stradbroke Island, QLD, is an area of dynamic coastal change. The township of Amity Point is situated on the northern-most point of North Stradbroke Island and overlooks the South Passage, a primary tidal exit of Moreton Bay. In recent years, Amity Point has become a focal point for coastal investigations due to the westward encroachment of Rainbow Channel and the regular occurrence of submarine flow slides along its banks. Along the northern reach of Amity Point, significant, ongoing shoreline recession of up to 4.5 m per year is currently impacting private and council-owned land, prompting local landowners to erect a rock seawall to reduce further land loss. This study has been conducted to investigate the mechanism of long-term coastal recession along the northern reach and connect the observed shoreline change with broad-scale coastal processes in the area. Previous coastal investigations at Amity Point have identified several drivers of coastal recession along the northern reach, including wave shadowing and encroachment of the Rainbow channel. A revised theory is proposed incorporating these drivers, along with the most recent shoreline and ocean data and updated, site-specific coastal modelling to assess coastal erosion in the study area. This study has associated ongoing recession in the area with periodic fluctuations in sand supply from a wave-dominated spit formation to the site's east and cyclical erosion from tidal currents exiting through the South Passage. The findings of this study will be used to inform coastal erosion mitigation options for the northern reach area. [ABSTRACT FROM AUTHOR]