Contributors to Sustainability of Public Open Spaces in Nairobi, Kenya: An Evolutionary Approach

Abstract

Public open spaces play a significant role in the life, form, and human experience of cities. Growth of towns and cities results in greater urbanization within countries. Urban growth means increased numbers of people in cities who require access to social amenities. These social amenities include public open spaces in cities such as Nairobi. In Nairobi’s case, multiple public open spaces in its Central Business District (CBD) are under-utilized. These spaces do not fully perform their role as publicly accessible areas for commerce, transportation, transit, and recreation. There is therefore a dichotomy comprising an increased demand for public open spaces on one hand and a non-optimal use of such existing spaces on the other. This research focused on elements of urban form and usage that entailed study of public open spaces and surrounding environments. Fifteen public open spaces in the Nairobi CBD were investigated. Six key variables were identified for analysis namely connectivity, density, enclosure, land use, space size, and tree cover. Through these, the research established the spatial evolution of public open spaces in the CBD from 1963-2015. It then established the social, economic, environmental, and governance factors that influence the sustainability of public open spaces. Thirdly it established the relationship between spatial evolution and sustainability of public open spaces in the CBD. The thesis hypothesized that the sustainability of public open spaces in Nairobi CBD is influenced by social, economic, environmental, and governance factors. A descriptive and quantitative approach was employed in this research. Therein, social, economic, environmental, and governance variables were used to measure characteristics of public open spaces. Observation forms and interview schedules were the instruments used for data collection. Maximum variation sampling was used to determine sample size and selection of subjects of study. Photographs and maps were reviewed to pattern spatial changes over the 1963-2015 timeframe. From these, base maps, figure-ground maps, land use maps, and 3-Dimensional (3D) models were developed and analysed for each space. Research results indicate that from 1963-2015, CBD public open spaces have become more sustainable with regards to connectivity, enclosure, density, mixed use, and tree cover. They have

however become less sustainable in terms of space size. Results also indicate that social sustainability is influenced by spatial and economic factors. The specific predictors of sustainability are the number of services in ground floors of buildings facing space, number of connectors to the space, and number of users of sidewalks surrounding the space. Results further indicate that environmental sustainability and governance sustainability are influenced by spatial factors. The former predictors are the area of the space and the longest distance of the space, while the latter predictors are proximity of space to the public transport hub, the number of parking spaces in the space, and area of paved pathways in the space. Lastly, results indicate that economic sustainability is influenced by social and economic factors. The number of users of the space, number of service businesses in the space, and number of retail shops in ground floors of buildings facing the space are its predictors. Research conclusions indicate that the social, economic, and environmental sustainability are not necessarily concurrent but that one aspect of sustainability can be dominant at a time. In addition, improvement in social sustainability means economic, environmental, and social improvement of public open spaces in Nairobi CBD. Also concluded was that achievement of socially sustainable spaces is the most complex and comprehensive of the four aspects of sustainability. Research recommendations are that more mixture and diversity of uses be encouraged around public open spaces. In addition, in order to enhance social sustainability, creation of environments that enhance economic activities are recommended. Also recommended is that efforts to enhance sustainability of spaces can be undertaken in phases. Lastly, as spatial factors are significant predictors of three aspects of sustainability, spatial interventions should be prioritized in improvement of the sustainability of public open spaces.