Coastal Erosion Management in Ghana: Combining Local Knowledge with Empirical Research.

Abstract

Coastal erosion along the Accra coast has become a chronic phenomenon that threatens both life and property. The issue has assumed a center stage of national debate in recent times due to its impact on the coastal communities. Lack of reliable geospatial data hinders effective scientific investigations into the changing trends in the shoreline position. However, perception about coastal erosion by the local people and how far the shoreline has migrated inland over time is high in the coastal communities in Accra. This opens a new chapter in coastal erosion research approach to include local knowledge of the local settlers in developing sustainable coastal management. This paper adopted a scientific approach to estimate rate of erosion and tested the results against perceived erosion trend by the local settlers. The study used 1974 digital topographic map and 1996 aerial photograph. The end point rate statistical method in DSAS was used to compute the rates of change. The short term rate of change for the 22 years period under study was estimated as -0.91 ± 0.49 meters per annum. It was revealed that about 79 % of the shoreline is eroding while the remaining 21 % is either stabilized or accreting. It emerged from semi-structured interviews with inhabitants in the Accra coastal communities that an average of about 30 meters of coastal lands are perceived to have been lost to erosion for a period of about 20 years. This translates to historic rate of change of about 1.5 meters per year, which corroborate the results of the scientific study. Again this study has established that the local knowledge of the inhabitants about coastal erosion can serve as reliable information under scarcity of scientific data for coastal management analyses in developing countries.