Mapping seasonal hazards for flood management in Accra, Ghana using GIS

The Greater Accra Metropolitan area experiences seasonal floods almost every year. Widespread rains characteristic of the May-July wet season, Accra's low elevation, the clayish nature of its soil, inadequate and undersized drains, the dumping of refuse into drains and water bodies, and the development of environmentally sensitive areas are the major causes of flooding in the city. This paper reports an investigation into the application of the geographic information systems (GIS) and other technologies for mapping urban flood zones in Accra for managing urban flood hazards. GIS-based software was used to process and analyse the slope. The results revealed notable flood risk zones and watercourses in the study area. The identification of flood-prone zones will assist city planners and managers in locating where to establish measures to deal with: the problem. It will also help emergency response teams identify areas in which to focus their operations during times of flooding.