Sea Level Rise

Sea level rise is one of the most significant global consequences of climate change and has become a major focus of international scientific research and coastal management. Rising global temperatures accelerate the melting of glaciers and polar ice sheets. This melting adds freshwater to the oceans, while increasing ocean temperatures cause thermal expansion, reducing seawater density and increasing the overall volume of the world's oceans. Long-term observations from tide gauges around the world consistently demonstrate a rising trend in mean sea level. Numerous scientific studies have projected future sea level rise under various climate change scenarios. One of the most direct consequences for coastal areas is the gradual landward migration of the shoreline. Therefore, accurate shoreline change assessments must consider not only erosion and accretion caused by waves and sediment transport, but also the long-term impacts of global sea level rise.

Numerical modeling provides a comprehensive scientific approach for evaluating the combined effects of global sea level rise and local coastal processes on future shoreline evolution. This integrated approach combines coastal inundation models, which incorporate high-resolution topographic data, with ocean circulation models driven by tides, currents, waves, and wind forcing. Coastal inundation modeling is particularly important for low-gradient (gently sloping) coastal plains, where even a relatively small increase in sea level can result in extensive shoreline retreat and widespread coastal flooding. Long-term simulation scenarios, ranging from several years to multiple decades, enable coastal planners and decision-makers to evaluate future shoreline changes, identify vulnerable areas, and develop effective adaptation and coastal protection strategies.

The modeling framework typically integrates several numerical modeling modules. Hydrodynamic Models simulate tidal circulation, coastal currents, and water level variations. Spectral Wave Models, Wave Analysis Tools, and Boussinesq Wave Models evaluate wave energy, wave setup, and wave-induced water level increases. Overland Flood Models simulate coastal inundation by incorporating topographic data together with projected sea level rise scenarios. Coastal Morphology Models predict long-term shoreline evolution resulting from the combined effects of sea level rise and coastal processes. Finally, all simulation outputs are integrated within a Marine Geographic Information System (Marine GIS) to support spatial analysis, vulnerability mapping, and science-based coastal planning.

The numerical modeling modules commonly applied for sea level rise assessments include: