Sustainable urban mobility: Flexible bus service network design in the post-pandemic era

Urban green vitalization and its impact on green exposure equity: A case study of Shanghai city, China

Urban green space (UGS) provides multiple ecosystem services to enhance the residents' well-being in the cities. As a characterization of differences in the degree of interaction between residents and UGS, Green exposure equity, has been recognized as an environmental justice issue. In this study, we propose the concept of urban green space' vitalization (UGV) as a primary criterion for assessing whether the UGS' functions or services are realized. Taking Shanghai, China as a case study, we developed an assessment system for UGV, and quantified UGV's availability to examine the impact on green exposure equity. Our research shows that 1000 m is the optimal service radius to determine whether UGS vitality is realized. All UGS in the central regions of Shanghai have realized their vitality, while areas devoid of vitality are mainly located in the non-central. Compared to UGS, the availability of UGV in Shanghai was cumulatively reduced by 321.07 km2, 10,812.61 km2, and 197,496.54 km2 for walking, public transport, and driving modes, respectively. In the non-central regions, the minimum green availability per capita for walking and public transport modes was reduced to 0 ha. The influence of UGV on green exposure equity varies depending on research scales and travel modes, as it is affected by heterogeneity in the distribution of UGS and population. Our research confirmed that UGV significantly reduces green availability and influences green exposure equity. Green exposure equity could be significantly improved by UGV under public transport mode and the district scale. Therefore, UGV is an essential factor in quantifying the equity of green exposure. Our research can serve as a basis for more realistic measurements of green exposure equity, providing insights for improving environmental justice in sustainable cities.

A significance of smart city pilot policies in China for enhancing carbon emission efficiency in construction

The Chinese government seeks to promote economic growth and sustainable development while achieving carbon neutrality by establishing phased smart city pilots. Therefore, it is important to study whether smart city pilots can promote carbon emission efficiency (CEE). This paper constructs a multi-period difference-in-difference (DID) model based on panel data from 241 prefecture-level cities in China from 2007 to 2019, aiming to investigate the mechanism of the impact of smart city pilot policies (SCPP) on CEE and whether there is a rebound effect. The study found that smart city construction (SCC) significantly improves carbon efficiency, with pilot cities increasing their CEE by 1.4% compared to non-pilot cities. The conclusions remain robust under a variety of scenarios including the introduction of placebo tests, counterfactual tests, sample data screening, and omitted variable tests. The results of the mechanism test show that although the rebound effect can inhibit the improvement of CEE, the environment can be improved and the CEE can be enhanced through green technology innovation, industrial structure upgrading, energy structure optimization, environmental regulation effect, information technology support, and resource allocation effect. The heterogeneity results indicate that the SCPP is more effective in promoting CEE in cities in the eastern region, southern cities, environmentally friendly cities, large cities, and medium-sized cities. This study contributes to the existing literature in clarifying the environmental benefits of SCPP and provides valuable policy insights for cities to address climate change and sustainable development.

Spatial-temporal characteristics and influencing factors of carbon emission in Chengdu-Chongqing area: an urban transportation perspective

The Chengdu-Chongqing twin-city economic circle is a vital growth pole and a new power source for Chinese high-quality development. Studying the spatial-temporal characteristics of carbon emissions and the role of factors affecting them under the transportation perspective is of great significance for this region to realize the carbon peak and carbon neutrality and to formulate carbon emission reduction policies. We use the exploring spatial data analysis (ESDA) and spatial regression model combined with the STIRPAT model, and research finding: (1) The total carbon emissions in the research area gradually increased from 2014 to 2020, but the growth rate showed a significant decline in 2019. (2) There is significant spatial heterogeneity of carbon emissions in the study area; the hotspot areas of total carbon emissions are in Chongqing and Chengdu, forming a high-low aggregation of carbon emissions. Per capita carbon emissions show a high trend in the southwest and a low in the northeast. (3) From the factors of transportation perspective, highway density and private vehicles have a positive impact on carbon emissions, and urban road areas and public transportation have a very significant inhibition of carbon emissions and a spatial spillover effect. (4) Other factors, such as population size, national economic development, urbanization level, and industrial structure, all have a positive effect on carbon emissions, and disposable income has a negative effect on carbon emissions.