Projecting sea-level rise and assessing its impacts on the mainland of Saint Vincent for the year 2300.

Supervisor: Phil Goodwin (NOCS, Southampton).
The islands of the Caribbean are predominantly associated with high coastal populations, small sizes and limited resources. Along with these characteristics, the region is frequently affected by storms. This makes it highly vulnerable to both the impacts of resulting storm surges and sea level rise. Current sea level rise projections until 2100 do not indicate any stabilization by this time, but rather show a continual increase. In order to assess the impacts of sea level rise and storm surges beyond 2100, this study first used an extended Earth System Model to project global sea level rise values until the year 2300. These global projections were then scaled to the mainland of Saint Vincent and the Grenadines and the integer values of the upper limits of each RCP scenario were extracted. The storm surge values were taken from a recent report of two locations on the island. Using these values, the impacts on the island were assessed using a bathtub approach whereby the areas that had lower values were considered to be flooded. The impacts were further divided among the census divisions of the mainland and reported. For the projections, the averages of the local projections for the periods 2081-2100 and 2281-2300 were significantly higher than the averages of the global projections. With the primary focus on Saint Vincent, the census division of Calliaqua would suffer the greatest in terms of the total area, numbers in population, road and building infrastructure and agriculture from the impacts of sea level rise and storm surges. However, when percentages relative to each census division were taken into consideration, Kingstown would have the largest percentage of area affected, and Georgetown would be most impacted in terms of its population percentage. Furthermore, the mangroves would be highly impacted under any scenario. Notably, storm surges with the sea level rise had significantly higher impacts than sea level rise on its own. It was also observed that sea level rise from RCP 2.6 with a storm surge from a Category 4 Hurricane would have the same impact as sea level rise from RCP 8.5 alone, while a storm surge from a 1 in 150 year storm with the lowest sea level rise of RCP 2.6 would have the same impact as sea level rise of RCP 6 combined with a storm surge from a Category 4 Hurricane.