Exposure To And Impacts Of Flooding In Selected Urban Communities In Accra, Ghana: Examining The Implications For Building Resilience

ABSTRACT There is increased exposure of people and critical livelihood assets to flooding globally due to climate change and modification of the biophysical system through human activities. Flooding has become an annual phenomenon in Accra in recent decades and has severe impacts on the poor and vulnerable. Using transdisciplinary techniques across the social and biophysical sciences, this study examined the extent of exposure of urban population to flooding, and the assets and structures that are necessary for building resilience in two communities of differing characteristics in the Accra Metropolitan Assembly (AMA) and Adentan Municipal Assembly (AdMA). The data encompassed participatory learning approaches using focus group discussing, transect walk, community workshops, and key informant interviews, as well as Remote Sensing/Geographical Information Systems (GIS) using Landsat imagery. Supervised land use/ land cover (LULC) classification of Landsat imagery, followed by post classification change detection in land cover was undertaken. An exponential projection model was fitted for the defined periods 2030 and 2060 towards evaluation of flood exposure. A digital elevation model was overlaid on the land use maps to examine the influence of elevation on the flood hazard. The Community-based Risk Screen Tool-Adaptation and Livelihoods (CRiSTAL) was adapted from development oriented project management (with few modifications to suit the context) in analyzing the sex and age differentials in access and relevance to livelihoods assets, and the impacts of floods in the two communities. The study sites were Ogbojo and Glefe in the Adentan Municipal (AdMA) and Accra Metropolitan (AMA) Assembles respectively. The results showed increased occupation of previously unoccupied landscapes such as forests and wetlands in low elevation areas, evident in the increasing proportion of the built up urban space between 1991 and 2017. The projections show that close to a quarter of natural land cover in AMA and more than half in AdMA could be lost by 2030 with increased flood hazards. Furthermore, higher proportions of natural landscapes will be lost by 2060. Aside the increase in concretised surfaces, other factors including poor waste management, poor drainage system, poor spatial planning, and the land use in adjoining districts/ communities tend to exacerbate the flood hazard in the study sites. Thus, both external human and environmental/topographical factors influenced the extent of the flood hazard at the study communities. There was nuanced age and sex differential in the access and relevance of livelihood assets, but generally physical assets such as buildings and vehicles were the most relevant, followed by human assets. Glefe’s location as coastal community created exposure to multiple sources of the flood hazard, but also enhanced its socioeconomic resilience due to the availability of additional livelihood options from the sea and lagoon. Flooding had economic, social, and health effects. The economic impacts were the most prominent, as a disruption of all livelihood assets had some economic implications. The communities’ ability to respond to flooding was positively related to the robustness of community assets, adaptive capacity as well as engineering and socioeconomic resilience. Fundamental to the socioeconomic resilience was the capacity to access resources outside the community, engagement of community assets, and participation of diverse groups in responding to flooding. The study therefore recommends the enforcement of laws and regulations on land use practices, cross-regional planning, inter-regional and inter-district planning, and community involvement in planning in the quest to building resilient cities. Finally, the CRiSTAL tool should be amended to increase the number of assets under each asset category in order to enhance its usefulness in the highly heterogeneous urban settings