Urban Land and Development Management in a Challenged Developing World: An Overview of New Reflections

The urban development and management challenges of the developing world are well documented in the literature. However, the global built environment landscape is undergoing rapid changes. These changes are steeped in three fundamental imperatives, which have serious implications for the developing world. These imperatives are population growth and rising urbanisation; environmental challenges, particularly climate change and the quest to embrace sustainability as a panacea; and advances in technological development. This paper discusses these three imperatives with the view to teasing out their implications for urban development and management in the developing world. Consistent with the literature, the paper establishes that most of the population growth and rising urbanisation are occurring in the developing world, particularly Africa and Asia, and although these phenomena have the tendency to increase economic density and promote both private and public investment in urban development, especially construction/housing and related infrastructure activities, there are and will be several problems with them. These include land tenure insecurity, lack of access to decent affordable housing and the threat of destruction to heritage sites. Furthermore, environmental challenges such as poor waste management, and climate change are and will remain pressing issues requiring the adoption of sustainability credentials because of legislative requirements, moral suasion, and value addition. Despite the potential disruptive nature of technology with respect to some aspects of the built environment, it is recognised that advances in technology are essential to the achievement of optimal urban development and management outcomes in the developing world. The paper, therefore, recommends better understanding of the socio-economic, cultural, and political forces underlying urban growth in the developing world, factoring in technology and sustainability in urban development and management, and collaboration among relevant actors, particularly government and the private sector, for optimal outcomes.

PCA-Based Identification of Built Environment Factors Reducing PM2.5 Pollution in Neighborhoods of Five Chinese Megacities

Air pollution, especially PM2.5 pollution, still seriously endangers the health of urban residents in China. The built environment is an important factor affecting PM2.5; however, the key factors remain unclear. Based on 37 neighborhoods located in five Chinese megacities, three relative indicators (the range, duration, and rate of change in PM2.5 concentration) at four pollution levels were calculated as dependent variables to exclude the background levels of PM2.5 in different cities. Nineteen built environment factors extracted from green space and gray space and three meteorological factors were used as independent variables. Principal component analysis was adopted to reveal the relationship between built environment factors, meteorological factors, and PM2.5. Accordingly, 24 models were built using 32 training neighborhood samples. The results showed that the adj_R2 of most models was between 0.6 and 0.8, and the highest adj_R2 was 0.813. Four principal factors were the most important factors that significantly affected the growth and reduction of PM2.5, reflecting the differences in green and gray spaces, building height and its differences, relative humidity, openness, and other characteristics of the neighborhood. Furthermore, the relative error was used to test the error of the predicted values of five verification neighborhood samples, finding that these models had a high fitting degree and can better predict the growth and reduction of PM2.5 based on these built environment factors.