• Energy Research

Abstract With the increasing urbanization but growing resource scarcities, the securing provision of fundamental resources as food, energy and water (FEW) has become a unique challenge for urban sustainability. This is not only because of continuous demand of resource imports from different regions for urban areas, but also due to the complex interrelationships among FEW systems. In such context, exploring the interactions between FEW resources and economic activities when investigating FEW provisions to meet urban demand through trade is very essential to find effective policy intervention points and priority areas for actions. This paper investigates external binding FEW resource flows with internal certain interlinkages driven by final demand of Beijing city at different nodes along their supply chains, by combing structural path analysis and multi-regional input-output model of China 2010. The results show that the key source regions present overall neighborhood pattern that Hebei, Inner Mongolia, Anhui, Jiangsu, and Shandong near Beijing are the five leading contributors of tran-regional FEW provisions. The top 20 nexus paths are identified and the most important nexus pathways start with the other services in Beijing. Besides this, the critical supply chains appear divergent directions for FEW flows, driven by food, construction and agriculture industries respectively. Moreover, the key nodes mainly concentrate on less developed regions and energy-related sectors. For example, non-metal products manufacturing in Hebei, petroleum refining and coking in Heilongjiang, and coal mining and washing in Inner Mongolia have larger impacts on all of FEW flows across the supply chains. These results are very informative to targeting our efforts to address the urban FEW nexus issue both from the perspective of supply side and demand side.

AbstractThe urbanization process continues to accelerate over the past decades, bringing great wealth to mankind, but also brought a lot of environmental problems such as the air pollution, water pollution and the solid waste pollution. These pollutants are to a certain extent cause some influences on the development of the cities. For example, the “cancer villages” has become a hot topic these years and has aroused extensive attention among scholars. This study aims to understand the relationship between the “cancer villages” and the “large cities” around them. The ecological network analysis is used to analyze the relationship between cancer villages and the adjacent large cities. The network utility analysis is used to analyze the intensity and patterns of the relationships between “cancer villages” and the large cities, and a mutual index M is established to reflect the degree of mutualism between the “cancer villages” and the large cities. The results show that “cancer villages” both affect and are affected by cities through indirect feedback relationships. Moreover, the composition between the “cancer villages” and the adjacent cities is a highly competitive urban metabolic network. Considering these indirect connections, not all of the “cancer villages” are able to reduce their pollution by transferring it to another city or county because it can return through indirect pathways. The best approach would be to lower the pollution generation in the first place in order to prevent its impacts, as well as to at least partially mitigate them through more effective medical care.

The fractal heat-conduction problem via local fractional derivative is investigated in this paper. The solution of the fractal heat-diffusion equation is obtained. The characteristic equation method is proposed to find the analytical solution of the partial differential equation in fractal heat-conduction problem.

Abstract In China, environmental problems associated with excessive energy consumption are escalating with rapid economic development, and the greenhouse effect caused by increased carbon dioxide emissions has risen into the focus of domestic and even international attention. Based on the reduction target China committed in 2015 Paris Climate Agreement, the study proposes a dynamic factorization model to decompose and compare the effect of industrial structure on the reduction of carbon emissions during the five Five-Year Plan (FYP) Periods from 2006 to 2030 at the dimensions of industries and sectors. Results show that China's industrial restructuring exerts a positive impact on reduction of carbon emissions and the impact varies with the ratio of sectors within the economic structure, in the later five years, carbon reductions emissions causing by restructuring in the three major industries and in the secondary industrial sectors account for 28.22% and 4.26% of the national total carbon reductions emissions respectively; in industrial sectors to mitigation was less than in the three major industries in the past two FYP Periods, but will increase in the next three FYP Periods. These findings are significant for the government in formulating environment and economy policy and planning.

Abstract An emergy-based comparison analysis is conducted for three typical mega cities in China, i.e., Beijing, Shanghai and Guangzhou, from 1990 to 2005 in four perspectives including emergy intensity, resource structure, environmental pressure and resource use efficiency. A new index of non-renewable emergy/money ratio is established to indicate the utilization efficiency of the non-renewable resources. The results show that for the three mega urban systems, Beijing, Shanghai and Guangzhou, the total emergy inputs were 3.76E+23, 3.54E+23, 2.52E+23 sej in 2005, of which 64.88%, 91.45% and 72.28% were imported from the outsides, respectively. As to the indicators of emergy intensity involving the total emergy use, emergy density and emergy use per cap, three cities exhibited similar overall increase trends with annual fluctuations from 1990 to 2005. Shanghai achieved the highest level of economic development and non-renewable resource use efficiency, and meanwhile, lower proportion of renewable resource use and higher environmental pressure compared to those of Beijing and Guangzhou. Guangzhou has long term sustainability considering an amount of local renewable resources used, per capita emergy used, energy consumption per unit GDP and the ratio of waste to renewable emergy. It can be concluded that different emergy-based evaluation results arise from different geographical locations, resources endowments, industrial structures and urban orientations of the concerned mega cities.

With the growth of energy consumption, energy-related environmental pollution has become increasingly serious, which in turn causes enormous economic loss because of public health damage, corrosion of materials, crop yield reduction, and other factors. Evaluating economic loss caused by energy-related environmental pollution can contribute to decision making in energy management. A framework for evaluating economic loss from environmental pollution produced during energy production, transportation, and consumption is proposed in this paper. Regarding SO2, PM10, and solid waste as the main pollutants, economic losses from health damage, materials corrosion, crop yield reduction, and solid waste pollution are estimated based on multiple concentration-response relationships and dose-response functions. The proposed framework and evaluation methods are applied to Beijing, China. It is evident that total economic loss attributable to energy-related environmental pollution fluctuated during 2000–2011 but had a general growth trend, with the highest value reaching 2.3 × 108 CNY (China Yuan) in 2006. Economic loss caused by health damage contributes most to the total loss among the four measured damage types. The total economic loss strongly correlates with the amount of energy consumption, especially for oil and electricity. Our evaluation framework and methods can be used widely to measure the potential impact of environmental pollution in the energy lifecycle.

Abstract Energy, water, and carbon dioxide are interdependent and have complex interactions through the economic supply chains of cities. Reviewing the state-of-art advances in the urban energy-water-carbon (EWC) nexus can help identify suitable tools for EWC management in cities and hotspots for future urban EWC nexus studies. However, systematic reviews of studies on the urban EWC nexus are lacking. This study fills this knowledge gap by conducting a systematic review of the advances in urban EWC nexus studies. The results indicate that nearly 94% of the urban EWC nexus studies focus on the nexus between two of the three aspects, with the ‘energy-water nexus’ representing the mainstream topic, especially at the product/sector scale (energy/water products or sectors). However, relatively few nexus analyses have been performed for the synergies and trade-offs among the three aspects as an integrated whole. This review reveals that unclear system boundaries of a nexus or city and imprecise urban inner structures may be the main limitations for urban EWC nexus studies. Moreover, the development of a theoretical framework is proposed, and methodological breakthroughs and key research directions urgently needed for urban EWC nexus in the future are highlighted.

As China's photovoltaic (PV) sector experiences rapid growth, the availability of land resources has become a pivotal policy focus, driving the need for comprehensive research and strategic planning for roadside PV initiatives. Utilizing a fuzzy multi-criteria decision-making approach, combined with GIS spatial analysis and a modular design framework, our study quantitatively compared the carbon reduction capabilities of PV systems against the carbon sequestration potential of various vegetative arrangements along the roadside space. The roadside space analysis modular considers a range of factors including topography, meteorology, and construction costs. We examined the spatial distribution of suitability for PV installation and vegetation establishment along the provincial expressway network in China. The results revealed that Inner Mongolia stood out as the frontrunner in carbon reduction potential within high-suitability zones for PV construction, achieving an impressive 4.845 million tons of carbon reduction—nearly four times greater than that of Shaanxi Province. In contrast, the carbon sequestration attributed to vegetation greening in areas less suited for PV development revealed a higher propensity in the southeastern provinces. Guangdong led the charge with an impressive annual carbon sequestration of 2.89 million tons. This was closely followed by Yunnan, Sichuan, Hebei, Guizhou, and Henan, each achieving carbon sequestration amounts exceeding 2 million tons. These results offer valuable quantitative support and practical recommendations for achieving low-carbon objectives in the construction of China's expressways.

Abstract Rapid urbanization and population agglomeration in cities result in massive construction and replacement of building stock with unceasing material flows that interact with the environment. The large quantities of material consumption and induced construction and demolition (C&D) waste have already led to severe resource and environmental problems in China. In this study, a system dynamic model under STELLA platform, was developed to simulate the urban residential building flow changes and related steel demand as well as C&D waste generation for the city of Beijing from 1949 to 2100. Results show that the residential building flows and related stocks of Beijing city will largely vary under different scenarios. The baseline scenario witnessed the construction flow peak in 2010 and projects that the building stock will saturate in 2059 with a total building floor area of 8.79E+8 m2, and the largest demolition activity is expected in 2079 with a demolished floor area of 1.65E+7 m2. Overall cyclical dynamics are observed for construction and demolition flows under middle and long-lifetime scenarios, but not prominent for short-lifetime scenarios. If effective urban mining strategies are implemented, up to 70% of future primary steel demand could be satisfied by recycled steel from C&D waste for baseline scenario. The results obtained in this study illustrate the significant resource and environmental saving potential of prolonging the building lifetime and strengthening recycling practices, and highlight the great need of effective policy intervention for waste management infrastructures planning in advance.