Abstract:
Changes to coastlines and bathymetry alter tidal dynamics and associated sediment transport process, impacting
upon a number of threats facing coastal regions, including flood risk and erosion. Especially vulnerable are coral atolls such
as those that make up the Maldives archipelago which has undergone significant land reclamation in recent years and decades,
and is also particularly exposed to sea level rise. Here we develop a tidal model of Male’ Atoll, Maldives, and use it to assess
potential 5 changes to sediment grain size distributions under sea level rise and coastline alteration scenarios. The results indicate
that the impact of coastline modification over the last two decades at the island scale is not limited to the immediate vicinity
of the modified island, but can also significantly impact the sediment grain size distribution across the wider atoll basin.
Additionally, the degree of change in sediment distribution which can be associated with sea level rise that is projected to occur
over relatively long time periods is predicted to occur over far shorter time periods with coastline changes, highlighting the
10 need to better understand, predict and mitigate the impact of land reclamation and other coastal modifications before conducting
such activities.
