Vulnerability and risk levels of communities within Ankobra estuary of Ghana

Abstract

Communities in the Ankobra estuary are generally rural and have a high vulnerability and risk to floods. However, there is little scientific evidence on the nature of floods; exposure of communities to floods and a flood risk map to help effective flood risk reduction and management within the estuary. This is as a result of limited attention given to flood occurrences at local scales. This study therefore sought to assess flood risk within the Ankobra estuary. Data were collected through interviews, community participatory mapping, observations and geographic information systems techniques (onscreen digitising, global positioning system mapping and spatial multi-criteria evaluation). Results from the study indicated that the estuary experiences three types of flood namely riverine, coastal and urban. Risk levels derived ranged from extreme, 0.75–1; high, 0.5–0.74; medium 0.25–0.49 to low, 0–0.24. The extreme risk zone covered an area of 46,725m2; high risk zone covered 701,525m2; moderate risk zone, 248,150m2 and low risk zone, 9,167,758m2. The study therefore recommends that people who live within extreme and high risk zones should be relocated to low risk zones while those in medium risk should undertake retrofitting of their buildings to minimize flow of flood water into their houses and rooms.