Innovative Technique of Predicting Shoreline Change in Developing Countries: Case of Accra Erosion and Causal Factors
The world over, coastal zones are known to support a wide range of critical habitats, unique biodiversity, host 50% of human populations and site development projects. These make coastal zones quite complex, dynamic and fragile and therefore challenging t
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Innovative Technique of Predicting Shoreline Change in Developing Countries: Case of Accra Erosion and Causal Factors Kwasi Appeaning-Addo and Emmanuel Lamptey
Abstract The world over, coastal zones are known to support a wide range of critical habitats, unique biodiversity, host 50% of human populations and site development projects. These make coastal zones quite complex, dynamic and fragile and therefore challenging to manage. Shoreline status assessment is an invaluable tool for coastal resource management given the escalating impacts of emerging global geophysical changes, such as rising sea levels, and rapid coastal development. In this contribution, shoreline change detection of Accra, Ghana was modeled with an innovative technique that combined dated historic maps, aerial photography, satellite imagery, conventional or global position system (GPS) ground surveys and laser altimetry data. Such a technique shows the relative response of coastal geomorphic features and geology to coastal processes. The results of the assessment revealed that the Accra shoreline has receded at an average rate of 1.13 m/year, which is attributable to several factors. This rate of change poses a looming threat to coastal lands and infrastructure in the zone. Essentially, this study demonstrate that reliable historic erosion rates can be estimated using the proposed technique for developing nations where geospatial data is scarce. These findings have important implications for formulating reliable and sustainable coastal management strategies in developing countries.
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Introduction
The coastal zone, the world over, constitutes one of the highly invested and populated areas. Coastal zones harbour many major cities and as such support about 25% of global productivity (Al-Tahir and Ali 2004) and home to about 50%
K. Appeaning-Addo (*) • E. Lamptey Department of Marine and Fisheries Sciences, University of Ghana, P. O. Box LG 99, Legon, Ghana e-mail: [email protected]; [email protected] C.W. Finkl (ed.), Coastal Hazards, Coastal Research Library 6, 367 DOI 10.1007/978-94-007-5234-4_14, # Springer Science+Business Media Dordrecht 2013
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of global total population (Woodroffe 2003). Increasing levels of industrialization and fast growing economy in most coastal areas poses looming threats to the ecology and economy of the zone. Threats to the coastal environment have reached an alarming proportion where it is estimated that about 38% of Africa’s coastal ecosystem is highly threatened (FAO 1998). This has called for urgent need to sustainably manage the resources of the coastal zone. Among the many benefits derived from coastal resources include provision of habitats for valuable biodiversity (e.g., wildlife); dunes create excellent natural flood barriers and natural filter for drinking water; salt marshes absorb wave energy during storm surges and minimises erosion; and beaches are an essential asset for generating revenue from the tourism industry. Ostensibly, sustainable managemen
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