Investigating the major causes of morphological transformations in the cbd of Accra and the impact on urban heat island intensity

Tropical urban sites are constantly under the threats of the adverse effects of urban heat island (UHI) – a situation which is aggravated by climate change. Urban morphology comprises a large set of factors that play an important role in modifying urban climate and, consequently, the potential energy demand and supply in cities. Ghana has since independence, experienced a rapid population growth, which has resulted in the urbanisation of many of its towns. Being the country’s capital city, the rapid growth of Accra has been fuelled by rural-urban migration, natural population increase, booming economic activities, political factors among others. The influx of people into the urban areas means there is a high demand for more housing, commercial and other infrastructural developments. For Accra however, this drive has resulted in drastic reduction in urban greenery. The aim of this study is to investigate the main causes of morphological transformations that have occurred in Accra over the past few decades, with the view to identifying possible measures for UHI mitigation. This study employs a mixed-methods research approach. First, to gain an in-depth understanding of the underlying causes of the morphological transformation the city has undergone, qualitative data are gathered through desktop studies and face-to-face semi-structured interviews with some experienced Ghanaian built environment professionals. The quantitative study involves the collection of weather data from selected monitoring points in the city. Upon analysing the qualitative data, other major causes of the morphological transformations that have emerged include: poor enforcement of development control, non-adherence to building regulations; inadequacies in the existing building regulations; architects and building designers lacking the motivation for sustainable design etc. It is evident that areas with large expanse of hardscapes and significantly reduced greenery are experiencing high UHI intensities. Recommendations include measures which address the identified challenges as well as urban regeneration.