Isaac Boateng

An assessment of the physical impacts of sea-level rise and coastal adaptation: a case study of the eastern coast of Ghana

Sea-level rise is a major coastal issue in the 21st century because many of the world’s built assets are located in the coastal zone. Coastal erosion and flooding are serious threats along the coast of Ghana, particularly, the eastern coast where the Volta delta is located. Past human interventions, climate change and the resultant rise in sea-levels, increased storm intensity and torrential rainfall have been blamed for these problems. Accelerated sea-level rise and storm surge pose serious threat to coastal habitat, bio-diversity and socio-economic activities in the coastal zone of Ghana and elsewhere. There is the need for an holistic assessment of the impacts of sea-level rise on the coast zone in order to formulate appropriate adaptation policies and strategies to mitigate the possible effects. Using the eastern coast of Ghana as a case study, this paper assesses the physical impacts of accelerated sea level rise and storm surge on the coastal environment. It evaluates adaptation policies and plans that could be implemented to accommodate the present and any future impacts. Field investigation and Geographic Information System (GIS) are among the methods used for the assessment. The outcome of the assessment has provided comprehensive knowledge of the potential impacts of accelerated sea-level rise and storm surge on the eastern coast. It has facilitated identification of management units, the appraisal of alternate adaptation policies and the selection of the best policy options based upon the local conditions and environmental sustainability. Among other things, this paper reveals that the eastern coast of Ghana is highly vulnerable to accelerated sea-level rise and therefore, requires sustainable adaptation policies and plans to manage the potential impacts. It recommends that various accommodation policies, which enable areas to be occupied for longer before eventual retreat, could be adapted to accommodate vulnerable settlements in the eastern coast of Ghana.

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 Ghanas 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 540km shoreline of Ghana is vulnerable. This assessment will facilitate the long-term adaptation planning and hazard mitigation to inform the management of Ghanas coast.

An Assessment of Vulnerability and Adaptation of Coastal Mangroves of West Africa in the Face of Climate Change

This chapter seeks to evaluate the current status of West Africa’s mangroves. It assesses Climate Change vulnerability and adaptation options for mangroves in West Africa. West African mangroves contribute a wide range of environmental services, economic goods and social services. In spite of the important contributions of mangroves in the region, they experiencing high rate of degradation. It is estimated that the degradation and the deforestation of mangroves in the region have resulted from their uncontrolled anthropogenic exploitation due to urbanisation, population growth, salt production, industrial pollution and the cutting of mangroves for firewood. Besides the afore-mentioned anthropogenic impacts on the mangroves, the anticipated effects of climate change such as increased temperatures, sea level rise, increased intensity of storm and precipitation are likely to have the most severe impacts on mangrove ecosystems. Climate change and the anthropogenic driven variations of these environmental forces will inevitably have a profound effect on coastal zones and mangroves. The challenge of reversing the degradation of mangrove ecosystems in the face of uncontrolled exploitation and impacts of climate change seems to be a very complex problem. This assessment has identified that both the past and the present vulnerability were more controlled by anthropogenic activities than the effects of climate change, though it is expected that climate change may be the major driving force in the long-term. However, many adaptation options exist to enhance specific ecosystem services in ways that reduce negative trade-offs, but these involve changes in policies, institutional framework and better practices for exploitation, and good management strategies. The chapter concludes that West Africa should implement adaptation policy options including reducing anthropogenic impacts, maintaining coastal buffer zones, restoration of mangroves, catchment management, establishing regional monitoring and regulations and education and local participation to enhance sustainability.