摘要：The frequency and severity of floods in Ghanaian cities have been increasing. Typically, increased floods have been attributed to climate change with limited evidence. Although this may be true in some cases, it minimizes the role of landscape change as a result of urban growth. Given the complexity of cities, this study characterizes urban morphology types and incorporate them with physiographic data to estimate the peak surface runoff in the Oforikrom Municipality of Ghana. The urban morphology was categorized into high, moderate and low dense human settlements, and further characterized based on the horizontal spacing between buildings, and the size and sanitary condition of storm water drains. The results identify vulnerable areas with information on surface runoff – thus facilitating the spatial targeting of intervention efforts. We found that room for flood waters is inadequate in terms of the capacity of storm water drains, and the land area left after human development. For storm water drains, the size is inadequate, their sanitary condition needs improvement, and their number need increasing based on catchment area. Informal and unstructured human settlements reduce the available room and artificially extend the flow path of runoff, which promotes flow accumulation thereby increasing the volume and destructive impact of flood waters. The study recommends intervention efforts to spatially target the creation of adequate room for flood waters to flow.
