Urban sprawl and green space depletion: Implications for flood incidence in Kumasi, Ghana

Urban area expansion has often been cited as a flood inducing factor globally. However, there is a dearth of research on how the phenomenon influences the occurrence of floods in Ghana. This paper examines urban sprawl-induced green space depletion and its attendant implications for urban flood incidence in a developing world context. Focusing on Kumasi, the study employed a combined use of geospatial techniques, key informant interviews and direct observations to explain the relationships between urban sprawl and flood occurrence. The study found that impermeable areas have expanded by 54% from 1986 to 2016 while permeable space correspondingly declined by the same rate within the period due to unplanned and unregulated urban expansion. The high proportion of impermeable surface, caused by urban expansion, underlies the worsening flooding situation in Kumasi. But the myriad of other factors such as poor spatial planning, inadequate storm drain infrastructure, poor waste management practices, and law enforcement lax combine to increase the intensity and severity of the floods. Adopting and enforcing smart growth policies are key in addressing the uncontrolled urban expansion and its associated flood challenges. Besides, land use control through legislative enforcement and prioritizing greening by the city authorities and other key stakeholders are essential for effective flood control and mitigation in Kumasi.