Mapping spatial and temporal dynamics in urban growth: the case of secondary cities in Northern Ghana.

Urbanization induced growth of secondary cities presents several issues and challenges for sustainable development. Yet, secondary cities continue to receive less attention from scholars, city planners and policymakers in Africa. Understanding the spatial and temporal dynamics of secondary cities is critical for achieving Sustainable Development Goal 11. This paper examines the emerging spatial and temporal evolution of two secondary cities in Northern Ghana. The paper utilizes raster data (1990–2019) and applied landscape metrics to analyze spatial development in Wa and Bolgatanga municipalities along three concentric rings. The results show significant increase in built areas over the study period. Urban development in the two cities is becoming more or less fragmented, dispersed and contiguous. Inadequate spatial planning, weakly regulated development and uncoordinated land markets account for the fragmentated spatial forms. The two cities exhibit a monocentric form that fluctuates, is dynamic, and discontinuous. The paper reflects on the implications of the findings and suggests the need for a planned extension of secondary cities in Africa to generate efficient urban forms, curtail sprawl and protect the natural environment