Mapping Vulnerability and Risk of Ghana's Coastline to Sea Level Rise

Abstract

Coastal erosion and flooding are major threats to coastal dwellers, and the situation is predicted to worsen as a result of the impacts of climate change and associated sea level rise. In order to identify the level of vulnerability of various sections of Ghana's coastline for planning and future hazard management, a coastal vulnerability index approach was adopted for the creation of the relative vulnerability map. The coastal vulnerability variables used include geomorphology, coastal elevation, geology, local subsidence, sea level rise, shoreline change rates, mean tidal range, mean wave height and population density of the coastal areas. Risk factors were assigned to the various variables and all the factors were combined to calculate the coastal vulnerability for the coastal front of each administrative district along the coast. The outcome was used to produce a vulnerability index map of coastal districts in Ghana. The results revealed that parts of the central coast and the eastern coasts of Ghana were the most vulnerable. It was identified that about 50% of the 540 km shoreline of Ghana is

Physical Forcing Induced Coastal Vulnerability along the Gulf of Guinea

“…The coastal vulnerability index computed for the twelve coastal sections of GG These results confirm those obtained by [2] [9] and [11]. The vulnerability of these coastal sections is controlled by geomorphology, rainfall index and tidal range as reported by [3].…”

“…The strong vulnerability of these sections is linked to This coastal area lies between Ankobra River to Prampram and Benin border to Benin River. [2] and [9] have classified the central coast of Ghana in the moderate risk category, but in this study, this coastal section falls in the high-risk category of vulnerability. The difference observed could be attributed to the rainfall index which has been taken into account in this study.…”

“…The coastline is dynamic and is, therefore, an area of constant change. The changes depend on geology and geomorphology; the natural processes such as tidal, swell and wind sea waves exacerbated by sea-level rise [1] and annual rainfall change [2]. The changes of the coastline also depend largely on human activities such as urbanization, ports defense construction, removal of sand and vegetation and construction of barrage [3].…”

“…[9] has integrated coastal relief, subsidence, extensive, shoreline retreat, and high wave/tide energies into coastal vulnerability index defined by [10] to show that western part of Accra is highly vulnerable than the centre and the Eastern part. [2] has developed an index based on geomorphology, coastal elevation, geology, local subsidence, sea-level rise, shoreline change rates, mean tidal range, mean wave height and population density. This The study carried out by [11], based on processes (relative sea-level rise, tidal range, and wave height) and state factors (geomorphology, coastal slope, and coastline change rate) showed that vulnerability of the Ivorian coastal section increases eastward and, depends strongly on geomorphology and swell wave energy coming from southern Atlantic.…”

An assessment of the contribution of fluvial sediment discharge to coastal stability: A case study of Western Region of Ghana

“…The oceanographic climate in the study area shows an average significant wave height of about 1.2 m and a significant wave period between 10 and 12 s (Wellens-Mensah et al, 2002). Prevailing wave direction is south-southwest with a local sea level rise rate of between 2 and 3 mm/year (Boateng et al, 2017). Relatively low tides are observed in the study area with the neap and spring tidal ranges between 0.6 and 1.3 m, respectively (Wiafe et al, 2013).…”