Coastline Change

Coastline change is driven by both natural processes—such as wave action, storms, and sea level rise—and human activities, including sand mining, coastal reclamation, and other forms of shoreline development. These changes can have significant strategic, economic, and environmental consequences. From a strategic perspective, shoreline change may alter the extent of coastal land and affect territorial boundaries, infrastructure, and land use. Environmentally, it can lead to habitat loss or expansion, changes in sediment dynamics, and degradation of coastal ecosystems.

The primary processes responsible for shoreline change are coastal erosion, coastal accretion, and global sea level rise. Coastal erosion is the landward retreat of the shoreline caused by the removal of sediment, while coastal accretion is the seaward advance of the shoreline resulting from sediment deposition. Rising sea levels cause shorelines to migrate landward as increasing ocean water volumes inundate low-lying coastal areas. In addition, erosion and accretion are strongly influenced by tidal dynamics, which affect sediment transport and shoreline evolution.

Numerical coastal modeling provides a reliable scientific tool for predicting shoreline changes associated with erosion and accretion. In contrast, projections of global sea level rise are typically produced using coupled global atmosphere–ocean climate models because their impacts extend beyond regional and national boundaries. Therefore, accurate assessments of shoreline change at the local scale require an integrated approach that combines local coastal processes—including waves, storms, and sediment transport—with global sea level rise projections. This integrated methodology provides more realistic predictions of future shoreline evolution and supports effective coastal planning, infrastructure design, and climate adaptation strategies.

Typical applications of numerical modeling for coastline change include: