Simulation of flooding in Keta municipal district

https://doi.org/10.13140/RG.2.2.26871.89762

The maps above illustrate the spatial extent of simulated flooding in the Keta, Abutiakope, Dzelukope, Tegbi, and Woe areas along the coast of the Volta Region, Ghana. The simulation employs a raster-based modelling technique to visualise progressive sea-level rise scenarios at 1 m, 2 m, and 3 m elevations above current sea level. This approach provides a visual representation of the potential impacts of coastal inundation due to climate-induced sea-level rise (SLR).

Analysis of the Maps

Map 1 serves as the baseline, showing the existing land cover and settlement pattern without sea-level rise. It highlights the dense coastal settlements and infrastructure in low-lying zones, which are inherently vulnerable to inundation.

Map 2 (Sea Level +1 m) demonstrates the initial stage of flooding, where a 1 m rise leads to noticeable encroachment of seawater inland, particularly around the lagoonal systems and coastal fringes. The inundation is concentrated in the southern portions of Keta and its environs, indicating the beginning of land loss in low-lying communities.

Map 3 (Sea Level +2 m) shows a significant intensification of flooding, with large portions of the coastal stretch submerged. The inundated areas expand northward and westward, threatening key settlements and transport corridors. This stage marks a critical threshold where a 2 m sea-level rise would likely result in displacement of populations, loss of agricultural land, and damage to coastal infrastructure.

Map 4 (Sea Level +3 m) reveals a worst-case scenario in which extensive areas of the Keta Lagoon Complex and surrounding settlements are completely submerged. The spatial extent of the floodplain indicates a near-total loss of habitable and cultivable land in some areas. This simulation underscores the magnitude of potential socio-economic and ecological disruption in the region under accelerated sea-level rise.