Prediction of Life Cycle Carbon Emissions of Sponge City Projects: A Case Study in Shanghai, China

Implementation path of dual-carbon in Xiguan historical and cultural district of Guangzhou：A case study on changhua street

In the context of ecological civilization construction, cities are the main source of greenhouse gas emissions and thus they are key areas for dual-carbon construction. The dual-carbon community is the basic unit of the dual-carbon city and is essential for the promotion and construction of beautiful China. Guangzhou, as a historical and cultural city, is actively exploring the micro-renewal path of historical and cultural neighborhoods. In this paper we explore the micro-renewal process of the dual-carbon community and the Guangzhou Xiguan historical and cultural district, as well as their mutual relationship. In particular, we take the historical and cultural district of Guangzhou Xiguan Changhua Street as an example and explore its carbon emission characteristics based on the Intergovernmental Panel on Climate Change (IPCC) inventory compilation method. The carbon emission of this community in 2022 was determined as 3774670 kg, indicating the characteristics of low carbon emissions per capita but high energy consumption. Changhua Street provides a dual-carbon micro-renewal strategy and suggests a dual-carbon implementation path for the Guangzhou Xiguan historical and cultural district in the micro-renewal process.

Comparative Analysis on Urban Flood Countermeasures Based on Life Cycle Thinking: A Comparison between Enhancing of Drainage Capacity Project and Sponge City

The recent increase in rainstorm waterlogging disasters has acutely threatened sustainable urban development in China. Traditional strategy to solve this problem is drainage capacity enhancing projects, which aims at enlarging the discharge of water. Recently, there is a new countermeasure emerged in Chinese cities: ‘Sponge City’, which aims at enlarging the absorption of water by increasing the curves of urban land. This article endeavours to make a comparison between these two countermeasures by building a framework to design and analyze the private or social costs of two projects which have the same rainwater control capacity. Finally, we have come to the conclusion that only considering initial cost, Sponge City unit cost is much more than drainage capacity enhancing project unit cost; considering external cost, Sponge City is not only competitive from an economical perspective, from an environmental perspective Sponge City is also competitive.

Analyzing Evidence of Sustainable Urban Water Management Systems: A Review through the Lenses of Sociotechnical Transitions

Sustainability concerns and multiple socio-environmental pressures have necessitated a shift towards Sustainable Urban Water Management (SUWM) systems. Viewing SUWM systems as sociotechnical, this paper departs from eight factors previously identified by transition research: Pressures, Context, Purposes, Actors, Instruments, Processes, Outputs, and Outcomes as a methodological framework for a structured review of 100 articles. The study seeks to analyze empirical cases of planning and implementing SUWM systems worldwide. A wide range of public actors—driven by social and environmental factors rather than by economic pressures—have initiated SUWM projects so as to locally fulfill defined social and environmental purposes. We provide evidence on the emergence of new actors, such as experts, users, and private developers, as well as on the diverse and innovative technical and societal instruments used to promote and implement SUWM systems. We also explore their contexts and institutional capacity to deal with pressures and to mobilize significant financial and human resources, which is in itself vital for the transition to SUWM. Planned or implemented SUWM outputs are divided into green (wet ponds, raingardens, and green roofs) and gray (rain barrels and porous pavements) measures. The outcomes of SUWM projects—in terms of societal and technical learning, and their institutional uptakes—are often implicit or lacking, which seemingly reduces the rate of desirable change.

GIS-Based Social Cost–Benefit Analysis on Integrated Urban Water Management in China: A Case Study of Sponge City in Harbin

Climate change along with industrialization or urbanization, which uses materials with low water permeability and is accompanied by change in urban land use, are major reasons for frequent urban floods in many Chinese cities. Moreover, upgrading the drainage system can have numerous negative environmental impacts on the city, especially in districts with dense population and buildings. A new integrated urban water management (IUWM) strategy implemented in China, “sponge city,” has gained significant attention in recent years. In this study, a novel framework is built to analyze the effectiveness of sponge city by 3D simulating urban inundation results and performing a cost–benefit analysis. Construction and maintenance fees are included in the costs list, and carbon reduction, air quality improvement, rainwater harvesting, and reduction of flood risk are included under benefits. The district of Nangang in Harbin city in Northeast China was chosen as a case study area. Finally, we conclude that the maximum precipitation of 49.82 mm/h by sponge city can bring the inundation depth below a target depth in the target area. Further, though the sponge city project is not effective from a private perspective, it is effective from a social perspective.

Analysis of the Effects of the River Network Structure and Urbanization on Waterlogging in High-Density Urban Areas-A Case Study of the Pudong New Area in Shanghai

In the process of urbanization, high-intensity human activities have seriously disturbed the river networks, especially in the core urban areas of large cities. At present, a series of urban water environmental problems, such as urban waterlogging and non-point pollution, caused by damage to the river network structure and the decrease in surface permeability conditions in high-density urban areas have received widespread attention. In this study, the effects of the river network structure and urbanization on urban waterlogging were analyzed in the Pudong New Area by using the data of waterlogging sites on the Amap. The results showed that the average water surface ratio is 10.9%, the average river network density is 4.59 km/km², and the comprehensive impervious ratio is 42.8%. From northwest to southeast, the impervious ratio of the Pudong New Area decreases gradually, and the water surface ratio and the river density increase gradually, while the areas with high waterlogging density are mainly concentrated in the northwest districts. The correlation coefficients indicate that the river network structure (-0.710 and -0.716) has a greater impact on waterlogging than urbanization (0.608) does. The current water surface ratio (10.9%) of the study area generally meets the requirements of the suitable water surface ratio (10.0%) in a rainfall return period of 50 years. However, the water surface ratio and the river density in about half of the districts did not meet the requirements of the suitable river network structure.

Tracking the Spatial–Temporal Evolution of Carbon Emissions in China from 1999 to 2015: A Land Use Perspective

China has been a leader in global carbon emissions since 2006. The question of how to reduce emissions while maintaining stable economic growth is a serious challenge for the country. To achieve this, it is of great significance to track the spatial and temporal evolution of carbon emissions in China during recent decades, which can provide evidence-based scientific guidance for developing mitigation policies. In this study, we calculated the carbon emissions of land use in 1999–2015 using the carbon emissions factor method proposed by the Intergovernmental Panel on Climate Change (IPCC). The Kuznets curve model was used to explore the influence of economic growth and urbanization on carbon emissions at the national and provincial levels. The results indicated that (1) China’s emissions increased from 927.88 million tons (Mt) in 1999 to 2833.91 Mt in 2015 at an average annual growth rate of 12.94%, while carbon sinks grew slightly, from 187.58 Mt to 207.19 Mt. Both emissions and sinks presented significant regional differences, with the Central and Southwest regions acting as the biggest emissions and sink contributors, respectively. (2) Built-up land was the largest land carrier for carbon emissions in China, contributing over 85% to total emissions each year; and (3) at the national level, the relationships between economic growth, urbanization, and carbon emissions presented as inverted U-shaped Kuznets curves, which were also found in the majority of the 30 studied provinces. While carbon emissions may be reaching a peak in China, given the disproportionate role of built-up land in carbon emissions, efforts should be devoted to limiting urbanization and the production of associated carbon emissions.