Urbanization leads to the occupation of green areas, directly contributing to a high level of fragmentation of urban green spaces, which, in turn, results in numerous socioeconomic and environmental problems. Consequently, an understanding of the relationships between patterns of urban green spaces and urbanization processes is essential. Although previous quantitative studies have examined this relationship, they have not included an exploration of spatial heterogeneities in the effects of urbanization on the spatial patterns of urban green areas. We therefore applied a spatiotemporal perspective to examine the above relationship, while considering the wider planning context. First, we quantified the extent of fragmentation of urban green spaces using landscape metrics comprising the largest patch index (LPI) and landscape shape index (LSI). Next, using the calculated spatial metrics and nighttime light data (NTL) for central Beijing for the period 1992–2016, we applied a geographically weighted regression model to assess variations in the spatiotemporal effects of urbanization on the fragmentation of urban green spaces. The results showed that urbanization initially occurred mainly in the northern parts of Beijing, whereas urbanization of southern urban fringe areas occurred after 2008. The reduction in green spaces along with increasing fragmentation and complex spatial patterns are indicative of issues relating to Beijing’s rapid urbanization and planning policies. This study contributes to an understanding of how urbanization influences fragmentation of urban green spaces and offers insights for the planning of urban green spaces from the perspective of promoting sustainability.

Urban renewal provides valuable opportunities for sustainable development. Sustainability assessment is considered a useful tool in ensuring sustainable development in practice. Although a number of studies have been conducted to evaluate the potential of urban renewal, studies on sustainability assessment in urban renewal at a neighborhood scale are often ignored. However, urban renewal is normally accompanied by many social, economic, and environmental conflicts among various stakeholders. The present paper proposes a framework for assessing neighborhood sustainability to support urban renewal decision making in high-density cities such as Hong Kong. This framework includes two components: (1) sustainability and building condition and (2) a decision-making matrix for urban renewal strategies. A case study was conducted to illustrate how this framework can be applied in the decision-making process of urban renewal projects. The results are expected to provide references for urban renewal decision making in high-density cities.

In China, urban housing demolition increasingly challenges the maintenance of social sustainability. Social sustainability is a multi-dimensional concept that contains complex implications. Therefore, an assessment system that considers a range of key social indicators could substantially simplify this concept and improve decision-making pertaining to sustainability practices. However, no such system exists in studies on housing demolition. To bridge this gap, this study sought to develop an assessment system for measuring the social sustainability of urban housing demolition. Firstly, an interview-based pilot study was conducted with scholars and practitioners to develop an optional list of indicators that reflect social sustainability. Subsequently, these indicators were validated via focus group meetings with key stakeholders in housing demolition programs. In addition, a two-wave questionnaire was designed to collect data to quantitatively analyze these sustainability indicators. Based on the questionnaire data, the indicators were ranked according to their relative importance and classified into five categories. Finally, the score of social sustainability of Shanghai was calculated to examine the impact of current housing demolition practices. The results showed that health and safety, social equality, and adherence to the law were the most critical dimensions that determined the social sustainability of urban housing demolition in Shanghai. The authors also found that to achieve greater social sustainability, existing housing demolition practices should be modified to reduce the negative impacts on the daily lives of residents that lived near demolition sites.Department of Building and Real Estat