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Highlights • The first city-level building energy efficiency benchmarking system for China. • A model considering the influence of operation parameters on energy consumption. • A systematic methodology of building energy benchmarking is proposed. • The model is a valuable analysis support tool for building energy managers. Abstract The city-level public building energy efficiency benchmarking system has an important guiding value for building energy-saving work, especially for Beijing, with its high energy-consumption density and both long heating and air-conditioning periods. This paper analyzed the characteristics of large-scale office buildings in Beijing and gives a detailed description of the process of establishing a public building energy efficiency benchmarking system for large-scale office buildings in Beijing, China, including data investigation and verification, Energy Usage Intensity(EUI) calculation, determining independent and dependent variables, developing and testing the benchmarking model, and deriving the benchmarking rating table. Then the first city-level public office building energy efficiency benchmarking system in China is established based on 88 large-scale office buildings in Beijing. The results showed that the model's performance index R2 is 0.667 and gives a good representation. The process has a strong potential for replication for other cities in China and even for a national energy-consumption evaluation system. [ABSTRACT FROM AUTHOR]

Government, industry, and corporate behaviors all encourage companies to actively implement energy efficiency measures (EEMs) but few empirical studies have identified the specific barriers and drivers of EEMs and their relative importance. This paper aims to better understand the barriers and drivers of EEMs to help determine how policies and regulations support their proliferation. We conducted a questionnaire survey of the enterprises in the Beijing-Tianjin-Hebei industrial transfer, carefully reviewed related policies, and built the Condition-Resource-Management (CRM) model to screen out the main factors that affect the improvement of energy efficiency. The mechanism of enterprise energy efficiency improvement was analyzed from the three different perspectives of EEMs (implementation steps, factors, and actors), and the main factors in each stage of the decision-making process were identified. The results show that in the seven steps of EEMs, the importance of awareness and investment priorities is great. Both economic and regulatory barriers and drivers have a significant effect on the improvement of energy efficiency via profit and behavioral impacts. Finally, based on the analysis results, we propose that policy makers need to (a) pay more attention to economic and legal tools and (b) appropriately increase supervision and punishment, and (c) government should provide more financial and technical support to encourage enterprises to improve energy efficiency. [ABSTRACT FROM AUTHOR]

Abstract: Based on the various fog remote sensing information products abstracted from the polar orbit meteorological satellite data (NOAA and FY), this paper analyzes the characteristics of the frequency and distribution that dense fogs have taken place in the Beijing district from 2001 to 2005. Among those information products, the statistical graph of the foggy days in Beijing from 2001 to 2005 by means of satellite remote-sensing reflects the frequency that dense fog has occurred in the different regions in Beijing; and the statistical graph of the foggy days of each season by satellite remote-sensing shows the characteristics of the temporal and spatial change of the fog distribution in Beijing in different seasons; the fog degree index(like pixel-level spatial measurement) by satellite remote-sensing reflects the fog frequency difference on unit area in different counties of Beijing. Meanwhile, based on the satellite remote-sensing pictures, data on the main meteorological elements that contribute to the formation of fog, geographic information, and DEM data, this paper makes an analysis in 3 areas, the traits of the fog distribution in the different regions of Beijing in different seasons; meteorological causes for temporal and spatial changes of the main fog types (advection fog, radiation fog). This paper also gave a brief introduction of the general principles of meteorological satellite remote sensing fog, fog information extraction method, as well as the process of satellite orbit selecting according to the ground visibility, data processing and product generation. [Copyright &y& Elsevier]

Abstract: To establish a healthy and sustainable policy-driven agricultural insurance scheme, a discussion of the importance of Public-Private Partnerships (PPPs) is timely in light of the challenges that governments are facing against the backdrop of increasing scale and frequency of major agro-related natural disasters across the globe. Most recently in 2008, it is reported a total of 137 natural catastrophes led to overall economic losses of USD258 billion in the world. Moreover, as complexity and costs escalate, neither group - public nor private - can meet the challenge alone. This is particularly true for agricultural industry and rural areas in emerging economies that lack sufficient funds to deal with the increasing frequency and severity of natural disasters. Public private partnerships (PPPs), especially those involving reinsurance and capital market solutions, can improve risk management and prepare stakeholders for the consequences of uncertainties. A recent example is the agricultural reinsurance contract signed by the Beijing Municipal Government and Swiss Re. In 2007, Beijing imposed a new agricultural insurance policy for local farmers to promote the development of urban agriculture. Under the new policy, the Beijing municipal and district governments subsidized farmers up to 75% who buy agricultural insurances for certain crops/livestock, and 50% of management costs of the participating insurers are shouldered by governments. The municipal government also set up a protection funds for agro-related natural catastrophe events and regulated the loss ratio of 160% as an attachment point to start up the fund. In this paper, we apply the non-parameter information-diffusion model to stimulate possibility of different loss incurred in Beijing using time-series combined loss ratio data of historical agricultural insurance business. The results show that the current attachment point of protection fund, 160%, will impose additional financial burden to local government comparing to higher or lower points. It proves the necessity for government introducing reinsurance in the system to diversify risks and improve efficiency simultaneously. The paper also outlines the overall framework of Beijing agricultural insurance scheme for each stakeholder including direct insurers and reinsurers. [Copyright &y& Elsevier]

[Display omitted] • This paper focused on stable urban heat island which is lack of attention in current studies. • This paper used morphological spatial pattern analysis to identify the key zones. • This paper obtained the causes and characteristics of the stable urban heat island. People residing near stable urban heat islands (UHIs) experience a high long-term heat exposure, and the health consequences of such islands may be more severe than those of an expanding UHI; however, these areas are hidden in the overall heat island and not focused on. We developed a novel approach to identify the locations and ranges of stable UHIs by considering multiple frequency urban heat islands (MFUHIs). The MFUHIs were identified through multi-temporal remote sensing data and morphological spatial pattern analysis (MSPA), and the approach was applied in the case area of Beijing, the capital city of China. Specifically, the MFUHIs in Beijing were classified according to the landscape characteristics, based on the field survey and remote sensing data. The landscape indicators included land-use types, biophysical parameters (normalised difference vegetation index (NDVI), proportion of water areas, and impervious surface area (ISA)) and 3-D metrics (building density and building heights), which were considered causative factors. The relationship between the land surface temperature and landscape indicators was examined using ordinary least-squares (OLS) regressions and the Area Weighted Contribution Index (AWCI). The results showed that the MFUHIs in Beijing have four key zones, in which the surface temperature is more than 9 ℃ higher than the average temperature of the urban area, and the air temperature is 3.3–8.5 ℃ higher than the built-up temperature in the non-UHI area. The OLS regression and spatial statistics of the landscape indicators and surface temperature indicated that the regions in which area where MFUHIs occur could be characterised by a relatively high degree of impervious surface coverage, lack of green space and water area, and presence of low-rise and high-density buildings. The average number of building-floors in MFUHIs was between 1.93 and 2.64, and the number of floors in the entire study area was less than 3.6. Moreover, the building-densities in the MFUHIs were 16.25% to 27.62% higher than that in the whole study area. According to the result of the AWCI and field survey, the MFUHIs were classified into transportation, historical block, commercial, and city village high-temperature centre. The main findings indicated that certain regions between the city centre and rural areas, in which sound planning is not implemented, are the hotspots of UHI mitigation and risk elimination regions. The proposed approach can help policymakers develop targeted mitigation strategies in urban planning. [ABSTRACT FROM AUTHOR]

Integrated energy system (IES) is characterized by high self-consumption ratio of on-site generated renewable energy, high efficiency of conventional energy utilization and possesses a significant flexibility in its operation. This overall, constitute to the foundation of low-carbon communities. Considering economic and environmental benefits, this paper proposes a two-layer co-optimization model with the upper layer optimizing the IES configuration and the lower layer optimizing IES operation. A community in Beijing is introduced as a case study to analyze the benefits of IES and compared with the conventional energy system. Multiple scenarios are researched, including (a) IES for low-carbon communities with PV roof area limitation, (b) IES for each of the four building types with PV roof area limitation, (c) IES for low-carbon communities without PV roof area limitation. The results indicate that the optimized IES for community can reduce the cost by 25% and CO 2 emissions by 32% per year by considering the limitation of roof area for the PV system. Without this constraint, the costs and emissions could be reduced by 20% and 62%, respectively. In addition, IES is more appropriate for office and commercial buildings since their load characteristics allow for load shifting and community-level IES costs and emissions are 8% and 10% lower than building-level due to the complementary of community load. This study provides suggestions for the IES planning and application in low-carbon community. [Display omitted] • An IES with multiple renewable energy and energy storage subsystems is proposed. • A two-layer co-optimization model of IES design and operation is developed. • IES optimization results for building-level and community-level are compared. • Impact of roof area limitation for PV on IES optimization results is investigated. [ABSTRACT FROM AUTHOR]

The waterlogging disaster has become a major threat to the resilient development of cities, which needs a unified and systematic accounting framework to estimate potential waterlogging effects in terms of forming disaster prevention strategies. In this paper, we developed an emergy-based waterlogging footprint accounting framework applying depth-damage functions, input–output (IO) analysis and ecological footprint, considering both economic and environmental factors. Taking the old town Beijing as a case study, we simulated the urban waterlogging distribution with a hydrodynamic model (InfoWorks ICM) over different return periods (1, 2, 3, 5, 10, 20, and 50 years) at high resolution. This study first considered the economic impact caused by urban waterlogging to evaluate the direct economic loss and indirect economic loss by using the depth-damage function and IO model, respectively. The environmental loss was assessed with an ecological footprint and was unified by emergy with economic loss. Then, four emergy-based indicators were established to quantify the specific impacts of waterlogging on urban resilience. The results show that the waterlogging footprints grew constantly by 284.57% from 1 year to 50 years. The waterlogging footprints driven by environmental loss, which were overlooked, accounted for 13.02% of the total. The waterlogging footprint density and waterlogging resilience index showed high spatial heterogeneity, indicating that the sensitivity of subdistricts to waterlogging varies greatly. Our study provides a useful energy-based tool for assessing urban waterlogging losses and supports decision-making for waterlogging disaster mitigation and risk zoning management. • An emergy assessment of hydrological-based urban waterlogging loss was first conducted. • Losses of natural capital due to urban waterlogging disasters were quantified. • Economic and environmental losses were incorporated. • Urban waterlogging resilience was explained in context of metabolism. [ABSTRACT FROM AUTHOR]

In China, overlapped routes from multiple bus lines are widespread. Some buses are overcrowded while others have few passengers. The goal of this study is to reduce onboard passenger crowding without wasting bus capacity. This paper examines an extended multiple-depot vehicle scheduling problem (VSP) with multiple vehicle types. First, a bi-objective integer programming model was created. The trade-off between operating cost and passenger travel cost was established and the crowding cost due to different vehicle sizes was especially considered. Then, the capacity restraint incremental assignment algorithm and a vehicle scheduling method with multiple vehicle types were developed to find Pareto-optimal solutions that considered vehicle capacity constraints. Finally, the proposed methodology was validated using a real-world transit network in Beijing, China. The optimization results from about 1.18 million bus card swiping records show that our model and solution algorithm can effectively reduce the passenger crowding cost and avoid the waste of transport capacity. [ABSTRACT FROM AUTHOR]

• Water use efficiency evaluation based on 3D water footprint using SBM model. • Two scenarios for water use efficiency evaluation. • Analyzing the driving forces affecting water footprint change using the LMDI model. Water shortage and the conflict between water supply and demand have become the main constraints to the sustainable development of sustainable societies in Beijing-Tianjin-Hebei (BTH) region. Scientific evaluation of water usage efficiency and clarification of the three-dimensional water ecological footprint (EF 3D) drivers are of great significance for the collaborative environmental management of BTH region. This paper firstly explores the evolution of water footprint breadth (EF size), depth (EF depth) and EF 3D in BTH region from 2004 to 2020. Using the super-efficient SBM (Slacks-Based Measure) model with EF 3D to evaluate the water use efficiency of BTH region in two scenarios. 22 impact factors were selected to analyze the dynamics affecting the change of EF 3D in BTH region by using the LMDI (Logistic Mean Divided Index) model. The results show that: (1) The water resources pressure of the three provinces are in the overload state from 2004 to 2020, and the EF 3D is at its maximum in 2011–2015. The EF depth of BTH region is fluctuating up and then fluctuating down around 2012, and the most serious capital consumption of water resources stock is in Tianjin. (2) The water resources in Hebei are all in inefficient use. The water resources in Tianjin are in a state of inefficient use in some study years, and since 2014, the water resources are in a state of fluctuating increase and high efficiency. As for Beijing, the water resources are in a state of efficient use in the study years. On the whole, scenario 2 better reflects the water resources utilization efficiency situation and is more in line with the real situation. (3) The water structure and endowment of water resources are pivotal factors positively influencing the EF 3D. To mitigate EF 3D and achieve sustainable utilization of water resources, both Hebei and Tianjin have ample room for progress in elevating agricultural water-saving technologies, optimizing industrial structure, and enhancing water usage patterns. Agricultural water consumption is no longer the primary driver of water resource depletion in Beijing, necessitating focused attention on the impact of external water diversions in terms of local water displacement, optimization of water usage structures, and their role in supporting socio-economic development. Additionally, excessive reliance on external water diversions may entail associated risks that warrant consideration. [ABSTRACT FROM AUTHOR]

• City-centric global multi-region input-output models for Beijing and Shanghai are developed. • Factor contribution and critical path analysis are adopted. • Sector aggregation effect varies across sectoral datasets. Sector aggregation under the input-output framework may lead to deviation in results and the lack of detailed sectoral information, which hinder the targeted implementation of accurate sectoral adjustment policies. This paper explores the effects of sector aggregation on the embodied carbon emission of the residential consumptions of Beijing and Shanghai based on the city-centric global multi-region input-output (CCG-MRIO) model. Integrating with structural path analysis and structural decomposition analysis, the impacts of sector aggregation on the identifying of critical emission transmission paths and driving forces are also revealed. Three sector aggregation datasets are discussed to track the sector aggregation effect in 2012 and 2017. The findings show that the carbon emission results at 8 sector level better align with the results at the 22 sector level than those at 32 sector level. Moreover, sector aggregation will lead to the absence of some critical carbon transmission paths, some factor contributions on carbon emission also changed their directions at different sector levels. On the basis of clarifying the sector aggregation effect on embodied carbon emission, the research results provide a reference for similar studies to select the appropriate level of sector aggregation, to realize the goal of simplifying the calculation or gaining more detailed sectoral emission information. [ABSTRACT FROM AUTHOR]

• Comparing BEV and HFCV from operational, economic, and environmental perspectives. • Proposing a data-driven and simulation-based multi-objective optimization method. • Using LCA to estimate GHG emissions and energy consumption in C2G life cycle. • Using a real-world trajectory dataset to quantify energy demand at the micro-scale. • Different combinations of fuel and facility have benefits and downsides. In order to evaluate suitability of battery electric vehicles (BEVs) and hydrogen fuel cell vehicles (HFCVs) in freight transport systems, this paper proposes a data-driven and simulation-based multi-objective optimization method to deploy charging/refueling facilities for BEVs/HFCVs. The model considers three objectives, namely minimizing total system cost, maximizing service reliability, and minimizing greenhouse gas (GHG) emissions. In particular, a data-driven micro-simulation approach is developed to simulate the operation of freight transport systems with different vehicle and facility types based on the analysis of a one-week Global Positioning System (GPS) trajectory dataset containing 63,000 freight vehicles in Beijing. With the model, we compare the suitability of BEVs and HFCVs within three typical scenarios, i.e., BEVs coupled with Charging Stations (BEV-CS), BEVs coupled with Battery Swap Stations (BEV-BSS), and HFCVs coupled with Hydrogen Refueling Stations (HFCV-HRS). The results suggest that BEV-CS has the lowest total system cost: its system cost is 62.5% and 90.3% of the costs in BEV-BSS and HFCV-HRS, respectively. BEV-BSS has the lowest delay time: its delay time is 62.1% and 86.0% of the delay times in BEV-CS and HFCV-HRS, respectively. HFCV-HRS has the lowest GHG emissions: its emissions are 37.3% and 46.9% of the emissions in BEV-CS and BEV-BSS, respectively. The results are expected to be helpful for policy making and infrastructure planning in promoting the development of alternative fuel vehicles. [ABSTRACT FROM AUTHOR]

Promoting the coupled development of water, energy, and food (WEF) subsystems is a critical step to enhance synergies and increase efficiencies in the WEF nexus. However, the evolution and obstacles of coupled development are largely ignored. This study developed a framework dividing links in the nexus to select indicators and integrated models for the degree of coordination and obstacle diagnosis to explore the coupled development of the WEF nexus from 2000 to 2020 in the water-scarce megacities of Beijing and Tianjin. The results show that the average coordination degree of the WEF nexus in Beijing (0.315) and Tianjin (0.317) is at a low level, indicating a limited interaction between the WEF subsystems, while the coordinated development degree of the WEF nexus is increasing. The order degree of the WEF subsystems shows a two-level hierarchical structure, indicating that both similarities and differences are included in place-specific characteristics. Furthermore, obstacle factors are identified from water and energy subsystems, in which environmental water use (W3) and the energy consumption per gross domestic production unit (E4) played the most significant roles and require a higher priority in policy response. The results in this paper complement obstacle factor analysis in WEF nexus practice, and provide operational indicators for nexus governance. [Display omitted] • Linkages are divided into one-, two-, and three-resource scales. • The number of related official documents is used to define the weight of subsystems. • The water subsystem dominated the coupled development of the water-energy-food nexus. • The order degree of subsystems show a two-level hierarchical structure. • Key obstacle factors are identified from water and energy subsystems. [ABSTRACT FROM AUTHOR]

Identifying the structures of buildings in urban areas is a prerequisite for robust urban planning and regeneration. Owing to the diverse structural designs of urban buildings, automated approaches are required to classify building structures. Supervised machine learning is usually employed to classify various building characteristics. However, this approach requires significant labeling effort. Therefore, this paper proposes a new pre-clustering active learning method for building structure classification. The proposed method captures the statistical characteristics of samples and enhances the recognition of the most valuable training samples, thereby substantially reducing the labeling workload and improving the efficiency and effectiveness of classification. This method was tested via the classification of 3718 buildings in Beijing, China, into five common structures. The results showed that the proposed method could reduce labeling effort by 60% while achieving a promising 90% F1 score for overall classification performance, thus indicating its effectiveness. [ABSTRACT FROM AUTHOR]

• The failure of slurry TBM circulation pipeline is systematically presented. • Typical wear morphology is studied combining the measured data and numerical results. • The time–frequency characteristics of pipe in different strata are investigated. • A multiple parameters wear warning methods based on pipe vibration is proposed. The slurry TBM circulation system plays a crucial role in supplying the slurry to the excavation face and conveying the cut rock particles to the ground. Rock particles in excavated materials will cause damage and failure of slurry discharge pipelines, which seriously restricts the efficiency of slurry TBM tunneling. In this paper, the two major behaviors of wear and vibration that induce slurry discharge pipelines failure are systematically investigated based on a water delivery tunnel located in Beijing. The wear morphology of typical pipes is studied combining the measured wear data and CFD-DEM coupling simulation. The time–frequency characteristics of slurry discharge pipe in different strata are measured and analyzed. Furthermore, the variation of time–frequency characteristics with the decrease of pipe wall thickness is investigated, a multi-parameters early warning methods based on vibration characteristics is proposed for detecting pipe wear. The results show that The CFD-DEM coupling method and Archard wear model can accurately determine the location of the maximum wear point of various pipes conducive to local thickening of pipes. The elbow pipe joints are prone to fatigue damage and have a high risk of slurry leakage during transport of large-sized particles. When the pipeline is severely worn, the interaction between the rock particles and the worn wall causes local elastic deformation, resulting in a high frequency response of 50–150 Hz and a rapid increase in the kurtosis K. [ABSTRACT FROM AUTHOR]

• Urban and rural energy rebound effects in Beijing are studied by LA-AIDS model. • Energy rebound from substitution and income effects is decomposed by Slutsky equation. • Energy rebound effect of rural residents exceeded that of urban residents after 2010. • The income effect is the main source of the energy rebound effect in Beijing. • Energy rebound caused by various commodity groups presents obvious heterogeneity. With Beijing facing greater pressure for energy conservation, improving energy efficiency becomes more necessary. However, the energy rebound effect may weaken this energy-saving effect. Using the LA-AIDS (Linear Approximation of the Almost Ideal Demand System) model and simulation analysis, this paper evaluates the energy rebound effects of different commodity groups in Beijing's urban and rural households during 2000–2019. Then, the Slutsky decomposition equation is introduced to decompose the energy rebound caused by the substitution and income effects. Results suggest that: (1) The energy consumption of urban and rural residents shows a partial rebound in most years, and the energy rebound effect of rural residents exceeded that of urban residents after 2010. (2) The income effect from commodity price changes is the main source of the energy rebound effect both in urban and rural households. (3) The commodity groups Residence, Household facilities & Services, Transportation & Communication and Health care & Medical services have the same influencing direction on the energy rebound effect in urban and rural residents, while the commodity groups Food, Tobacco & Alcohol, Clothing and Culture, Education & Entertainment have different influencing direction. Finally, suggestions are provided for alleviating the energy rebound effect of households in Beijing. [ABSTRACT FROM AUTHOR]

As an environmentally friendly and convenient transport mode, bike-sharing has been fast developed in major cities around the world. More bike-sharing firms have been formed and intensified market competition. The government has stipulated regulations to intervene in bike-sharing firm operations and to maintain orderly competition. This paper establishes an integrated economic model to examine duopoly bike-sharing firm competition in both prices and the number of deployed bikes. Specifically, more deployed bikes in the urban area reduce the time cost for the users to find an available bike (i.e., the search cost), but they can also impose a negative social externality on the urban management. Two government policies to control the number of deployed bikes have been examined and benchmarked. One is the limit on the total number of the deployed bikes (i.e., the supply-side regulation), and the other is the restriction to allow the users to only register or use certain firms' services (i.e., the demand-side regulation of single-homing). Our model is also further calibrated by using the bike-sharing market data of Beijing for policy implications. It is found that, when the negative social externality of bike deployment is sufficiently small, the government should allow users' multi-homing (i.e., registration on both firms' platforms). However, when the negative social externality is high, the government should strictly control the number of bikes through both the supply-side and demand-side restrictions. Our analyses also suggest that it is never socially optimal to only adopt the demand-side restriction (i.e., forcing the single-homing). That is, the supply-side policy is more socially preferred to correct the negative social externality in most cases. When two bike-sharing firms offer quite heterogeneous services (i.e., low service substitutability), it is more socially optimal to only implement the supply-side policy. • Dockless bike-sharing firms compete in both price and number of deployed bikes. • The government adopts two alternative policies to control the number of deployed bikes. • With small negative externality, the supply-side regulation to limit deployed bikes is preferred. • It is never socially optimal to only adopt demand-side regulation by imposing single-homing. • The analytical model is also calibrated with real-world market data of Beijing for more insights. [ABSTRACT FROM AUTHOR]

Studies using Hedonic housing price model to discuss residents' demand for urban green space (UGS) demonstrate the importance that residents place on UGS. While much of the empirical findings have focused on residents' willingness to pay, more attention needs to be paid on its temporal change and spatial heterogeneity. Taking advantage of the diverse composition of urban parks, housing, and residents in Beijing, this paper explores the dynamic and heterogeneous demand for UGS. Using more than 240 thousand micro housing resale transaction data from 2011 to 2019, this paper constructs a Hedonic model to empirically estimate and confirm the basic, dynamic and heterogenous willingness to pay of residents for urban parks. Our empirical findings confirm the rising and heterogeneous demand for UGS by Chinese urban residents. First, the willingness to pay for parks of urban residents has continued to grow during our study period. Second, in view of different socioeconomic characteristics, there exists heterogeneous demand related to the housing of residents and different types of parks. Residents who live in homes with a larger size have a stronger demand for urban parks. Meanwhile, urban residents prefer parks with free entry over fee-based parks, and they have strong preference for some specific types of parks. Moreover, we conduct a survey and collect 907 valid samples to directly obtain residents' willingness to pay for urban parks, and the survey results further confirm the abovementioned findings. This study deepens the understanding of urban residents' demand for UGS, and will contribute to more scientific decision making on the planning, financing and management of UGS. • Hedonic price model was used to estimate residents' demand for urban parks in Beijing. • The willingness to pay for urban parks by residents has continued to grow during 2011–2019. • There exists heterogeneous demand for urban parks, which is related to both residents' income and park types. • The abovementioned findings were confirmed by questionnaire survey which directly obtain residents' willingness to pay. [ABSTRACT FROM AUTHOR]

The sharp rise in internet technology, and the influence of social media, along with the widespread use of affordable, intelligent devices, have significantly altered the way that users obtain information. The task here is to profit from massive amounts of data and the competence of the public to detect, when, and how the information is distributed, what people think or talk about it in social networks. Poor air quality is a grave concern for public health. Efficient and practical approaches are needed to detect harmful emissions. This paper evaluates the possible use of social networking sites by comparing Twitter data and justifying it with existing air monitoring stations to observe the air contamination of a metropolitan city. An Extended Temporary Memory (ETM) approach to air quality forecasting is proposed in this paper; besides, meteorological data are utilized with public perception, and Air Quality Forecast (AQF) response using social media is examined. Daily data on Air Quality (AQ), climatological conditions, and Weibo reception statistics have been collected in the city of Beijing, between January 2019 and December 2019. As a proxy for audience response, the mean emotion of the relevant posts has been used. Based on real figures, the performance of the proposed model has been assessed. Qualitative findings show that, out of 71.2% of air quality notifications, 80.7% of which were the first-hand study. Among the results, 31% reported aggressive behavior, while 20% shared a concern about safety. The findings have demonstrated that the suggested approach, which requires community feedback records, is ideally adapted for forecasting pollution levels in serious short-tenure communal incidents and offers rapid societal evaluation and ecological recommendations. • Measured the regular average, and deleted records of null values. • Include average daily temperature, dew level, moisture, intensity, humidity. • This paper evaluates the possible use of social networking sites. [ABSTRACT FROM AUTHOR]

As a basic structural unit of the city, the community plays a crucial role in decreasing carbon emissions and creating a low carbon city. This paper selects a classic and official low carbon community named Min'an Community in Beijing as a case to illustrate the governance mechanism of the low carbon community in China from the perspective of polycentric governance. The paper summarizes the government mechanism, market mechanism, and public participation mechanism in Min'an Community and analyzes the provision, monitoring, and enforcement of each mechanism. We find that unlike the low carbon governance at the city or industry park levels, China's low carbon governance at the community level lacks a dominant mechanism. Even though it involves community-wide governance, the public participation mechanism is also inadequate. For improving low carbon governance at the community level, the government should broaden finance channels to strengthen the incentive mechanisms, make active use of new technologies, such as mobile Internet, encourage innovation of public participation mechanism, and employ various publicity and education measures to cultivate the low carbon culture. [ABSTRACT FROM AUTHOR]

Photovoltaic–energy storage charging station (PV-ES CS) combines photovoltaic (PV), battery energy storage system (BESS) and charging station together. As one of the most promising charging facilities, PV-ES CS plays a decisive role in improving the convenience of EV charging, saving energy and reducing pollution emissions. To promote PV-ES CS and improve the network of charging facilities, it is necessary to explore its comprehensive benefits. Firstly, to make full use of peak-to-valley electricity price difference and consume the power generated by the PV, this paper introduces the energy management strategy of the station based on time-of-use (TOU) electricity price. Secondly, from the perspective of multiple beneficiaries, a comprehensive benefits analysis model of charging station is proposed, including the benefits of PV-ES CS, power grid and society. Finally, the comprehensive benefits of the new charging station are analyzed through a PV-ES CS in Beijing. The impact of the construction cost reduction (including BESS cost and PV cost) and subsidy decline on the economy of the charging station is discussed. The government should further enrich charging stations subsidies. The results show that the social and economic benefits brought by PV-ES CS are far greater than the economic benefits of the station itself. With the development of the new charging facility in the future, it will bring considerable social and economic benefits and play a vital role in saving energy and reducing emissions. • The paper analyzes the benefits of charging station integrated photovoltaic and energy storage, power grid and society. • The social and economic benefits brought by PV-ES CS are more significant, compared with its own economic benefits. • A comprehensive benefit analysis model of charging station is proposed. • The impact of the construction cost reduction and subsidy decline on the economy of the charging station is discussed. • Some policy recommendations are put forward based on the analysis. [ABSTRACT FROM AUTHOR]

Developing reliable frameworks to estimate the potential of CO 2 emission abatement and its associated costs merits urgent attention. This study aims to estimate the potential as well as macroeconomic costs of CO 2 emission abatement in Beijing. Using the industrial economy as the basis, multiobjective programming and genetic algorithm are integrated into the input–output analysis. Several important findings have been gathered in the study: (1) The abatement cost varies between $259.97 and $535.46 per ton at different rates of economic growth. (2) A reinforced emission abatement target can induce higher macroeconomic costs. (3) An inverse U-shaped relationship between CO 2 reduction cost and GDP growth rate was found. When GDP growth rate is above the threshold value of 7%, marginal abatement costs decrease rapidly in parallel with GDP growth. When the GDP growth rate is below 7%, the marginal abatement cost increases significantly with economic growth. (4) Industries that have the highest and least potential of abatement have been identified. For effectively reducing CO 2 emissions, Beijing needs to promote economic restructuring to maximize the potential of emission abatement and also fulfil the emission abatement target in a cost-effective way. This paper provides a quantitative approach to rationalize the policy design process of enacting emission targets and recommends cost-effective abatement strategies. [ABSTRACT FROM AUTHOR]

Ecological network analysis is an important tool for urban energy metabolism research, but it does not consider the dynamic and synergy features of the system, which constraints its application in urban transition studies. In this paper, we modified the ecological network analysis method to identify the key factors that dominate the evolution of the urban energy metabolism. Focusing on the dynamic and synergy characteristics of the system, we observed the changes of direct and indirect energy consumption flows and combined with Haken model to determine the dominant factors of the metabolic processes. A case study on Beijing was conducted to diagnose the key flows that impact the evolution of Beijing’s energy metabolic system during 2010–2015. Results suggest that despite the decline in Beijing’s coal consumptions, the direct and indirect parts have different tendency among sectors. During the research period, the pathway “ coal to industry ” displays dominant effects on the evolution of Beijing’s energy metabolic system. [ABSTRACT FROM AUTHOR]

The market of electric taxi has achieved rapid development in China recently, while further development is hindered by technical factors such as battery mileage and charging. First-tier cities as Beijing have explored and innovated in electric taxi business models to make up for the deficiencies caused by technological immaturity at the present stage. From the perspective of value chain, this paper carries out an analysis on current status of electric taxi business models in Beijing, and proposes a model for analyzing its economy. Moreover, a comparative analysis was conducted on the economy and sensitivity of battery changing and battery charging models based on field research data acquired from Pinggu District of Beijing. The research findings are as follows: a) overall, the battery changing model is better than the battery charging model economically. b) the sensitivity of the battery changing model to project period, carbon price and charging price is significantly higher than that of the charging model, because of its higher service frequency and greater service quantity. c) among all the influencing factors, charging price has the greatest influence on the two models. d) in the battery changing model, the breakeven point of the whole business model gradually declines as electricity price rises, so the battery changing model still can survive even without government subsidies. e) owing to vehicle loss, battery loss and other reasons, the two models have an optimal period respectively, but the greater loss of the battery changing model results in that its optimal project period is shorter than that of the battery charging model. [ABSTRACT FROM AUTHOR]

In previous urban planning research, the fine-grained population was considered a crucial factor. However, this population, which is generated from census data, represents only the number of people who live in a region. This static figure cannot indicate the underlying number of people and their temporal variation. Therefore, any decision-making based on the static population may be separated from reality. To overcome this difficulty, in this paper, the urban crowd flux is initially proposed and defined as the number of individuals flowing into or out of a region per unit time interval. Then, the urban crowd flux is estimated using an approach of human trajectory gridding reconstruction based on mobile phone location data. This approach is divided into three steps. First, the trajectory of each individual is extracted from sparse sampling of mobile phone location data after data cleansing. Then, combining with a road network, the trajectory of each individual is reconstructed by network interpolation based on the shortest path algorithm in regular grids. Third, we use the velocities of each user's trajectory record to estimate the urban crowd flux on spatio-temporal grids at each time slice. Finally, urban crowd flux in Beijing, China were estimated using our method and the spatio-temporal characteristics of flux is analyzed. [ABSTRACT FROM AUTHOR]

Based on the DBSCAN analysis, kernel density analysis and word cloud analysis, this paper analyzed the composition types and spatio-temporal evolution characteristics of catering points and catering clusters form macro, meso and micro dimensions within 5th ring road in Beijing with the caterings POI data in 2012, 2014 and 2016. The conclusions are as follows: first: (1) The number of total catering POI increased by about 6 times, and the center of the whole data shows a tendency to move from west to southeast. There is little change of quantity of total catering clusters. The distribution is relatively uniform. The scale of single catering cluster grows significantly, and the large-scale clusters have contiguous trends and the number of clusters in Chaoyang has been the largest, in Dongcheng and Xicheng varies at least. (2) The large-scale catering clusters are mainly distributed in the CBD, Sanlitun, Nanluoguxiang, Wangfujing, Zhongguangcun, and the scale of some clusters fluctuates. As the proportion of composition of main clusters, the Chinese food and casual dining continues to increase, while the western food decreased, there are similar trends in the type of catering. (3) The diversity of catering brands has increased year by year, among them, the proportion of small dining sites such as Shaxian snacks has increased obviously, and the proportion of fast food such as KFC has declined slightly but still considerable, and the time-honored brand such as Quanjude accounted for a downward trend. Second, the results obtained by POI data of time series are more objective and accurate. It is a meaningful attempt of data mining and analysis in the era of big data. [ABSTRACT FROM AUTHOR]

With China's rapid urbanization and industrialization, carbon emission in Chinese cities deserve special attention, and promoting low-carbon city (LCC) is considered essential for China. However, different cities present different development stages and carbon emission scenarios. This study presents the factors affecting carbon emission by introducing a city development-stage framework. The method of logarithmic mean Divisia index (LMDI) is adopted to decompose emission factors into energy structure, energy intensity, industrial structure, economic output and population scale. Beijing is chosen as the case city in this study, and four development stages for the city are identified by using the Environmental Kuznets Curve (EKC) theory, namely, S 1 (−1991), S 2 (1991–2004), S 3 (2004–2022) and S 4 (2022-). As the data collected for analysis are only available for the period of 1995–2014, this study focuses on the factor analysis for the stage S 2 and S 3 . The results show that the main driving factor for carbon emission increase in the stage S 2 is economic output, followed by population scale, while the main factor contributes to carbon emission reduction in this stage is the industrial structure. In the stage S 3 , the economic output is the top contributor to increase carbon emission, followed by population scale and energy structure, whereas energy intensity is the main influencing factor in curbing the carbon emission. Although the paper refers to the specific case of Beijing, the understanding on the driving emission factors in different development stages not only provides policy-makers and practitioners with valuable references for adopting effective measures to reduce carbon emission, but also provides other cities internationally with important lessons for accelerating the development of LCC. The innovative economic development stage framework incorporates carbon emission characteristics provides a new approach for understanding driving emission factors at city or national level. [ABSTRACT FROM AUTHOR]

Introduction Building a safe biking environment is crucial to encouraging bicycle use. In developed areas with higher density and more mixed land use, the built environment factors that pose a crash risk may vary. This study investigates the connection between biking risk factors and the compact built environment, using data for Beijing. Method In the context of China, this paper seeks to answer two research questions. First, what types of built environment factors are correlated with bike-automobile crash frequency and risk? Second, how do risk factors vary across different types of bikes? Poisson lognormal random effects models are employed to examine how land use and roadway design factors are associated with the bike-automobile crashes. Results The main findings are: (1) bike-automobile crashes are more likely to occur in densely developed areas, which is characterized by higher population density, more mixed land use, denser roads and junctions, and more parking lots; (2) areas with greater ground transit are correlated with more bike-automobile crashes and higher risks of involving in collisions; (3) the percentages of wider streets show negative associations with bike crash frequency; (4) built environment factors cannot help explain factors contributing to motorcycle-automobile crashes. Practical Applications In China's dense urban context, important policy implications for bicycle safety improvement drawn from this study include: prioritizing safety programs in urban centers, applying safety improvements to areas with more ground transit, placing bike-automobile crash countermeasures at road junctions, and improving bicycle safety on narrower streets. [ABSTRACT FROM AUTHOR]

In recent years, economy grows rapidly in China but it also pays a huge cost of destroy of resources and environment, and energy-saving and emission reduction has become a hot topic. This paper aims at calculating the environmental efficiency and environmental total factor productivity (TFP) of Beijing under the constraint of energy-saving and emission reduction to explore the relationship of the city’s economy and environment. We used an improved directional distance function – Biennial Directional Distance Function (BDDF) and Luenberger (L) productivity index which is corresponding to BDDF. This method can decompose the efficiency and productivity according to input and output factors and solve the problem of infeasible solution. The study found that the environmental efficiency of Beijing is different from regions and it takes on a concave distribution from the urban center to the edge of the city. Energy inputs and environmental pollution are the main influence factors of environmental inefficiency. The environmental TFP of the two central regions is higher than the two fringe regions, and through the decomposition results, we learned that the technology progress and the energy-saving emission reduction are the core of productivity growth momentum. From the change trend, the environmental efficiency of Beijing reached a high level in 2011 and followed by a slow decline. Whereas environmental TFP showed a tortuous rise trend which is down to the lowest in 2011–2012 and up to the highest in 2015. Based on our conclusions, we can say that energy-saving and emission reduction work of Beijing has made some good achievements, but with the difficulties increase we should take more reasonable measures according to the actual situation and join together to make the results of energy-saving and emission reduction work more effective. [ABSTRACT FROM AUTHOR]

• A deep learning approach to predicting the electric vehicle (EV) charging demand. • A real-world large EV trajectory dataset was used for model training and validation. • The deep learning approach outperformed traditional time series prediction models. • Input data structures, and sample sizes were not influential to prediction accuracy. Short-term prediction of the Electric Vehicle (EV) charging demand is of great importance to the operation of EV fleets and charging stations. This paper develops a Long Short-Term Memory (LSTM) neural network to predict the EV charging demand at the station level for the next few hours (e.g., 1–5 h), using a unique trajectory dataset containing over 76,000 private EVs in Beijing in January 2018. To explore the performance of the LSTM model, we set up four scenarios by 1) comparing LSTM against two typical time series prediction models, i.e., the Auto-Regressive Moving Average model (ARIMA), and the Multiple Layer Perceptron model (MLP), 2) and investigating how different input data structures, sample sizes, and time spans and intervals would influence model accuracy. The results suggest that the LSTM model outperformed the ARIMA, and MLP models, and their MAPE1 values are 6.83 %, 21.58 %, and 18.31 %, respectively. In addition, we find that the time span and interval tend to be more influential to the LSTM model's prediction accuracy than input data structures, and sample sizes. In general, the LSTM model with a shorter time span or interval (e.g., 1 h) would perform better. [ABSTRACT FROM AUTHOR]

• A regional division method of municipal solid waste incinerators based on incineration characteristics is proposed. • The material balance equation of municipal solid waste incineration (MSWI) process is established. • The energy balance equation of MSWI process is established. • A multi-input and multi-output controlled object model is constructed, which lays the foundation for optimal control. Municipal solid waste incineration (MSWI) is an important part of energy recovery and sustainable development, constructing the model of controlled object is the basis of studying its optimal control. MSWI is a typical multi-input and multi-output industrial process, which has many uncertain characteristics such as strong nonlinearity and multivariable coupling. To solve this problem, a model of controlled object in MSWI process is proposed in this paper. Firstly, the MSWI process based on grate incinerator is analyzed to summarize its relevant variables and control requirements. Secondly, the solid phase and gas phase of MSWI process are divided to construct material balance equations of subsystems. Next, the energy transfer process in incinerator is deduced and calculated through thermodynamic laws. Finally, the validity of the model is verified by the process data of a MSWI plant in Beijing, China, which lays a model foundation for the study of the optimal control of MSWI process. [ABSTRACT FROM AUTHOR]

The agricultural sector is extremely vulnerable to climate change and also plays a very important role in the operation of the entire economic system, leading many studies to evaluate the possible agricultural direct economic damage (ADED) of climate change. However, this damage may have an amplification impact through the intricate industrial linkages that exist among sectors, and this impact may be even greater than the original damage. Therefore, to elucidate the economic cascading effect (ECE) in China caused by ADED and industrial linkage, this paper used the ARIO model to evaluate the total ECE and analyse the differences in the 19 sectors by taking the ADED under future annual mean temperature (AMT) increases of 1–5 °C as the input condition and adjusting the exogenous parameters to enhance the adaptability of the model; the goal was to assess the economic impact of climate change in China. The results show that (i) there is a significant amplifying impact of ECE due to industrial linkage under the influence of warming, ECE will be 4.24–5.25 times that of ADED, and the total economic impact (ADED + ECE) will exceed the GDP of the Chinese capital of Beijing in 2012 when the AMT increases by 1.5 °C, while it will exceed one tenth of China's GDP when it increases by 4 °C. (ii) Manufacturing will be the sector most affected by the industrial linkage under ADED, which accounts for 26.58% of total ECE, followed by agriculture (10.39%) and construction (8.5%). (iii) The decrease in cultivated land area will have a significant impact on the economy; when it is reduced to the minimum demand (1.41% less than 2012), ADED increases by 1.65 times and ECE increases by 2.35 times. This paper aims to provide a new perspective from which to evaluate the economic impact of climate change by studying ECEs behind sectoral interactions. [ABSTRACT FROM AUTHOR]

New energy vehicles (NEVs) have great potential to reduce emissions containing atmospheric pollutants. The Chinese Government has implemented a series of subsidy policies to promote NEVs and replace traditional fuel vehicles (TFVs). However, the contribution of NEVs in reducing atmospheric pollutants varies due to differences in mileages and emission factors. Previous literature has rarely studied the influence of NEV subsidy policies on the reduction of atmospheric pollutants, especially with respect to different kinds of vehicles. This paper divides motor vehicles into four categories: buses, taxis, passenger cars, and special vehicles. Taking into account the purchase subsidies and construction subsidies on the charging infrastructure of NEVs, this paper proposes an evaluation index, namely, the comprehensive subsidy efficiency, that measures the effectiveness of the two subsidies in reducing emissions of atmospheric pollutants among different NEVs. In response to Beijing's plan to prioritize the promotion of battery electric vehicles (BEVs), this paper uses relevant data of BEVs instead of NEVs for the analysis. Taking Beijing as a case study, promotion proportion of NEVs were set according to the comprehensive subsidy efficiency of various NEVs; furthermore, scenario simulation of NEV subsidy policies in 2017 and 2020 was conducted. The results revealed new energy taxis and special vehicles have great a potential to alleviate the greenhouse effect and haze weather, respectively. By prioritizing the promotion of NEVs with higher comprehensive subsidy efficiency, one can achieve greater reduction in the emissions of atmospheric pollutants with equal financial funds. Furthermore, this paper suggests subsidy policies of NEVs from the perspective of reducing emissions of atmospheric pollutants. Image 1 • The paper studies different types of new energy vehicles. • The paper studies the influence of new energy vehicle subsidy policy on alleviating the greenhouse effect and haze weather. • The government should prioritize the promotion of new energy vehicles with higher comprehensive subsidy efficiency. [ABSTRACT FROM AUTHOR]

The advent of the energy Internet (EI) has dramatically changed the energy model of today's world. Despite scholars have done a lot of research on energy Internet, few articles have been written to evaluate its CO 2 emission reduction. In order to fill the vacancy, system dynamics (SD) is used to set up the dynamic assessment model of CO 2 emission reduction of regional energy Internet. To illustrate the effectiveness of the model, we take the energy Internet in Yanqing district of Beijing as an example for simulation. The results show that the total CO 2 emission reduction of this energy Internet will reach 5056.82 tons in 2019, and the emission reduction will continue to increase in the following years, the total amount of CO 2 emission reduction peaked at 13384.80 tons in 2030. We conclude: (1) The CO 2 emission reduction dynamic assessment model established in this paper has a strong versatility and can be applied to any built or planned energy Internet. (2) Energy Internet has a good long term effect in emission reduction. (3) The emission reduction of the supply side is the most obvious; the user side has the greatest potential for emission reduction, while the contribution of the transmission side to emissions reduction is the most stable. The innovation points of this paper mainly include: (1) we put forward and solve the dynamic assessment of carbon emission reduction on the energy Internet for the first time. (2) We establish a dynamic assessment model of CO 2 emission reduction in the energy Internet based on system dynamics. (3) We quantitatively analyze the emission reduction contribution of the supply side, transmission side and user side of the energy Internet. [ABSTRACT FROM AUTHOR]

This paper presents our participant observation in two urbanized villages in the northern suburb of Beijing. One is Dongxiaoko u (DXK), a concentrated garbage sorting/trading center, which expanded unexpectedly in the 2000s and crashed recently due to urban expansion, illustrating the distressing challenge of waste as it is gradually exposed to urban governance in China. The other is Zhenggezhuang (ZGZ), an urbanized village built by the local collective entity not far away from DXK. We initiated a community-based recycling program in this village. With the background of the municipality's efforts to remake the waste/recycling space into an “urban circular economic system”, we address the evolution of diversification and constant linkage between these two villages. In conclusion, we generalize the result of the research to give implications to the cross-scale interactions among the community action, the urban waste management system and the producer responsibility scheme. [ABSTRACT FROM AUTHOR]

Freshwater ecosystem service is essential to human’s survival and development. Many studies have documented the spatial differences in the supply and demand of ecosystem services and proposed the concept of ecosystem services flows. However, few studies characterize freshwater ecosystem service flow quantitatively. Therefore, our paper aims to quantify the effects of freshwater ecosystem service flow on downstream areas. We developed a freshwater ecosystem service flow model and applied it in the Beijing–Tianjin–Hebei (BTH) region, China, for the year of 2000, 2005, and 2010. We assessed the regional water security with an improved freshwater security index by integrating freshwater service provision, consumption and flow; and found that most areas of the BTH region (69.2%) were affected by upstream freshwater flows. The areas achieving water security in the region also expanded to 66.9%, 66.1%, and 71.3%, which were 6.4%, 6.8% and 5.7% increments compared to no-flow situation, in 2000, 2005 and 2010, respectively. Setting quota for human water consumption is suggested to further improve water security. These results highlight the need to fully understand the connections between distant freshwater ecosystem service provision and local freshwater ecosystem service consumption. This approach may also help managers to choose more sustainable strategies for critical freshwater resource management across different regions. [ABSTRACT FROM AUTHOR]

Long-term observation of the urban ecological footprint will present useful knowledge of anthropogenic impact on and sustainable solutions for cities. This paper proposed a new framework to predict dynamic change and intrinsic structure of urban ecological footprint with the Markov chain. The system dynamic model based on Markov chain was then established for estimating Beijing's footprint during the period of 2001–2020. The results showed that Beijing's footprint kept stable in the long term due to steady consumption pattern and environmental mitigation policy. The footprint intensity has been decreasing constantly due to the expanding population against the stable total footprint. Energy consumption was found to be the major contributor to Beijing's footprint. Sensitivity analysis was also presented by testing the population and economic growth under five scenarios. This work may provide insights into the land metabolism mechanism and guidance for urban planning. [ABSTRACT FROM AUTHOR]

Based on analysis of the wetland water resources system in Beijing city, this paper established a system dynamics (SD) model for the water resources carrying capacity (WRCC) in Beijing city. Using a computer simulation of the SD model, the variation trends from 2006 to 2030 in population, economy, water supply and demand, and pressure on the water environment were derived for Beijing, from which 12 core variables of the model were chosen as the WRCC evaluation indices. Five cases were designed in this study. The results indicate that the WRCC will continue to decline annually by following the status quo (Case 1), since the water environment will have difficulty in supporting the long-term social and economic development of Beijing. The status quo of Beijing’s socioeconomic development is therefore not sustainable. In order to address this problem, five optimization cases were put forward to improve the WRCC, and the carrying capacities and trends of the cases were compared and analyzed. Under Case 5, the WRCC (0.8 in 2030) will increase by 50%, compared to that in Case 1 (0.4 in 2030), while the water supply and demand ratio will be 20% higher than the average, and the water pollution will be 35% lower than the average in 2030. According to the analysis results, in order to guarantee sustainable utilization of water resources and social economy development in Beijing, it is necessary to increase water saving policies and pollution control investment in the future. Corresponding measures will need to be taken to ensure the implementation of water saving strategies to improve the water environment. [ABSTRACT FROM AUTHOR]

On November 28, 2013, Beijing’s carbon emissions trading opened on Beijing’s Environmental Exchange. As one of the pilot cities, Beijing has been pursuing low-carbon development strategies under state intervention and market regulation. This paper chooses the carbon market, a medium through which Beijing manages emission reduction, as the object of study. Firstly, we compare the basic construction circumstances of Beijing with other pilot cities. Then we qualitatively analyze the development of Beijing’s carbon market from the perspective of transaction status, execution of the contract, and improvement of the policies and regulations. Finally, we use the TOPSIS model to develop a comprehensive evaluation system of Beijing’s carbon market. It is used to quantitatively evaluate the operational performance and maturity of the mechanism. The results show that: Beijing’s carbon market has good comprehensive capabilities, ranking second place among seven pilot markets; but the maturity of Beijing’s carbon market is relatively poor for insufficient market liquidity; its operations are well managed, but economic efficiency still need to be improved; the depth of transaction and the effect of reduction in emissions make it meaningful. Therefore, in order to improve the construction of Beijing’s carbon market, measures should be taken as follows:(1) strengthening the quota management, and increasing carbon trading activity to avoid poor market liquidity; (2) accelerating emission reduction actions and encouraging technology innovation, such as: carrying out several policies and measures supporting new energy and energy saving & emission reduction, and increasing investment and subsidy in research and development for the technology innovation of firms etc.; (3) improving regulatory mechanism and enhancing the disclosure of carbon trading, such as: drawing lessons from the EU Emission Trading Scheme (ETS) about measuring, reporting and verification system (MRV). [ABSTRACT FROM AUTHOR]

A comprehensive GHG inventory provides an overview and the information of sources of emissions, and can serve as a sound scientific basis for mitigation actions. This study was the first initiative to develop a complete and transparent GHG inventory of Beijing, to document the current situation and to help governmental officials to clarify their priorities for reducing GHG emissions. The authors investigated and calculated the emission sources defined by the GPC, and assessed data accuracy. The contents of the detailed inventory were documented and are open for research verification and for methodological references for other cities. The results showed that three emission sources, i.e. CO 2 emissions from fossil fuel consumption, CO 2 emissions from industrial production and CH 4 emissions from landfills, contributed 97% of Beijing's GHGs. Considering the problem of missing data and low data quality, the authors suggested that instead of seeking to compile a complete inventory, Chinese cities should first report their GHG emissions from these sources, while improving the data quality for the long run. The authors anticipate that the findings reported in this paper will help to strengthen city-level GHG inventory research in China and throughout the world. [ABSTRACT FROM AUTHOR]

This study estimates the economic values of and the dominant contributors to five key ecosystem services of wetlands in Beijing, by using the wetland inventory data in 2014 and economic valuation methods. Results indicate that the 51,434 ha of wetlands in Beijing annually provide 2.07 billion m3 of flood regulation, 944.01 million m3 of water provision, 42,154 tons of chemical oxygen demand (COD) purification, 3.03 PJ of heat absorption, and 9587 ha of habitat. Their economic values are estimated to be 15.89 billion RMB, 1.19 billion RMB, 169 million RMB, 421 million RMB, and 1.08 billion RMB in 2014 (RMB: Chinese currency, US$1 = RMB 6.14), respectively. The total values of five key wetland ecosystem services reach 18.76 billion RMB. In addition, the reservoir and river wetlands in Miyun, Yanqing, Fangshan, Huairou, and Mentougou Districts contribute 78% of key ecosystem services, whereas the urban wetlands in Xicheng, Dongcheng, Haidian, Chaoyang, and Tongzhou Districts more conveniently serve densely local people, hence they should be given particular attentions. In this paper, we develop the valuation methods of wetland ecosystem services, and recommend diversified strategies, regulations, and programs to protect the remaining wetlands in Beijing. This work can also provide a reference for the valuating of wetland ecosystem services for other urban-rural areas. [ABSTRACT FROM AUTHOR]

Among the first batch of pilot cities for application and promotion of new energy vehicles determined in 2013, Beijing is also a pilot city for national energy conservation, demonstration and popularization of new energy vehicles as well as subsidization of private new energy vehicles purchase. 2016 marks the beginning of the “13th Five-Year Plan” and is hence expected to be a pivotal year for promoting new energy vehicles. Using the Fuel Life Cycle Assessment, this paper conducts a quantitative analysis of such battery electric vehicles being promoted in Beijing as electric taxis, electric buses, electric sanitation trucks and rental battery electric vehicles, based on which we forecast the battery electric vehicles’ performance during the “13th Five-Year Plan” in terms of energy conservation and emission reduction, as well as provide insights into the development path and the policy making for the industry accordingly. The results indicate a positive effect on energy conservation and emission reduction for all battery electric vehicles types currently on duty in Beijing, with an estimated 1.9 billion kilogram consumed energy of electricity conserved as well as 39.4 million tons of CO 2 emission reduced by the end of 2020. Factors like power generation structure and fuel type are found to be crucial for this emission reduction performance. [ABSTRACT FROM AUTHOR]

Nowadays, air pollution has become a major challenge in urban management despite rapid economic development. Meanwhile, vehicle exhaust has gradually turned into the main source of air pollution in the city. To reduce air pollution, many measures have been taken including the odd-and-even license plate rule in some cities. However, it is difficult to evaluate the effectiveness of those measures. In view of this, based on the Davis method, this article has taken Beijing as its subject and built an odd-and-even license plate model by a probabilistic modelling method and the analysis of means, thus to quantify the pollution caused by vehicle exhaust emissions and the actual effect of the license plate limitation rule. This paper also examines the relationship between the license plate limitation rule and urban air pollution control and to see whether, or not, the rule exerts a positive influence on air pollution control. The results showed that the odd-and-even license plate rule has positive impacts on air pollution control in the short-term; however, the influence of the limitation policy gradually diminishes and disappears as the overall number of cars increases. Therefore, it is suggested to tackle air pollution in a broader and more effective way. [ABSTRACT FROM AUTHOR]

In the functional zoning and comprehensive management of ecological and clean small-watersheds (ECSWs), measures to increase the carrying capacity of the environment should be taken around water resources protection and ecological risk governance. An objective zoning technology for ECSWs was recommended in this paper to tackle problems such as soil erosion and water pollution efficiently. Taking eight typical ECSWs in Changping District of Beijing as a case study, the essential data, including the land use, digital elevation, administrative division, leaf area index and annual precipitation, can be initially accessed. Subsequently, two topographic features (i.e., elevation and slope) and seven ecosystem disservices (i.e., collapse risks, debris flow risks, nitrogen pollution, phosphorus pollution, sediment export, quick flow and surface runoff) were evaluated and quantified based on Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) and Geographic Information System (GIS). The quantitative attribute matrix was herein operated as a calculation object of k -means clustering and entropy-weighted TOPSIS for the classification and delineation. According to the analysis results, the category and hierarchical control zones of each ECSW were determined, deducing the preliminary management layout. Several practical measures that have been verified to be available were marked in the layout map based on the high-resolution remote sensing technology, contributing to guiding the high-efficiency construction of ECSWs in the future. • InVEST and GIS models were used to evaluate the ecosystem disservices in ecological and clean small-watersheds (ECSWs). • K-means clustering and entropy-weighted TOPSIS methods were used to classify and delineate ECSWs in the study area. • Comprehensive management of ECSWs can be achieved systematically and standardly based on the classification and delineation. [ABSTRACT FROM AUTHOR]

Complete and high-quality deformation monitoring data are critical for shield tunnel construction safety and quality. In engineering practices, data missing frequently occurs during instrumentation, adversely impacting further analysis and decision making. Existing imputation methods either ignore the crucial interactions between different parameters during shield tunneling or focus on the global characteristics of deformation data while neglect their local difference. This paper proposes a novel hybrid model, MCCB, combining multi-view matrix completion algorithms, convolutional neural network (CNN), and bidirectional long short-term memory (BiLSTM) algorithms to impute missing deformation values in shield tunnel monitoring data. The performance of the proposed method is verified using bridge deformation data from a practical project in Beijing. Different missing patterns of the bridge deformation data are filled. The experiment results show that the proposed model can effectively learn the various characteristics of the deformation data and outperforms the four selected models and its two sub-models, and can be used to improve the accuracy of the deformation prediction through data imputation. The novelty of this study includes two aspects. First is that the complicated interaction between different parameters and local difference of the data are considered simultaneously. They have not been addressed before by existing studies. Second is that the innovative combination of matrix completion and deep learning algorithm for application in missing deformation values imputation. To our best knowledge, no research on engineering construction has implemented this technique before. [ABSTRACT FROM AUTHOR]

• The carbon emission coefficients method and net ecosystem productivity (NEP) were used to evaluate urban carbon emissions and green space carbon sinks, respectively. • A multi-objective programming model (MOP) was constructed to derive the optimal solution of the amount of urban green space based on the carbon balance theory. • Combined with ventilation resistance and species migration resistance assessment, priority distribution areas of green space in 2035 were identified. • The PLUS model was introduced to optimize the spatial pattern of urban green space. • Optimized green space network stability and carbon sinks will be enhanced in 2035. Cities experience the most intensive level of human activity. As a result, more than 60 % of global CO 2 emissions come from urban areas. Urban green space has the dual ecological benefits of increasing carbon sinks and reducing carbon emissions. Creating green space is essential to promoting the development of a low-carbon cycle in a city. Therefore, exploring the quantitative structure and spatial pattern optimization of urban green space from the perspective of carbon balance can effectively improve the total carbon sink of a city. Based on the carbon balance theory, this paper first evaluates the carbon offsetting capability (COC) of urban green space in Beijing in 2020. Then, CO 2 emissions is predicted, COC improvement targets are established, and the quantity of standard green space is calculated under these targets in 2035. A multi-objective programming model (MOP) is constructed to derive the optimal solution to determine the amount of standard green space needed to meet the constraints of urban development planning and maximize the carbon sink. A circuit model is used to identify the priority distribution area of green space in 2035, and the Patch-generating Land Use Simulation (PLUS) model is used to simulate the spatial pattern optimization results. The results show that: (1) CO 2 emissions in Beijing caused by human activities in 2020 totaled about 240.12 million tons, the net absorption of CO 2 of green space was about 8.99 million tons, and the COC was about 3.74 %; (2) in 2035, Beijing's CO 2 emissions will be about 265.40 million tons. Under 5 %, 10 %, 15 %, 20 %, and 25 % COC improvement gradients, the demand for standard green space will be 12,204.80 km2, 12,763.80 km2, 13,353.85 km2, 13,943.90 km2, and 14,533.96 km2, respectively; (3) the results of the Multi-Objective Programming (MOP) model show that the optimal COC in 2035 is 4.19 %, and the standard green space quantity is 13,012.24 km2; (4) In 2035, Beijing's urban green space will be characterized by a network structure of circular radiation. The optimized COC is 4.37 %, and the standard green space quantity is 13,577.86 km2, which is largely consistent with the MOP model's predicted result. This study can provide theoretical and methodological support for urban green space planning, and expand nature-based solutions for the low-carbon development in cities. [ABSTRACT FROM AUTHOR]

Land-use change and the associated influences on the carbon metabolism system should not be overlooked in the context of rapid urbanization. By combing carbon emissions/sequestrations accounting and ecological network analysis, this paper quantitatively described the general situation and spatial distribution evolution of carbon metabolism in the Beijing-Tianjin-Hebei (BTH) urban agglomeration from 2015 to 2019, investigated carbon flows induced by land-use change, and revealed the ecological relationships between the components of the system. The spatial distribution of carbon emissions showed a trend of high in the southeast and low in the northwest, while carbon sequestrations were the opposite. At the early stage of regional coordinate development, the migration of enterprises with heavy energy consumption and emission and expansion of the transportation network has promoted the economic development in the surrounding area of Beijing, but also lead to the carbon emission transfer and the severe imbalance of carbon metabolism. Despite that a slight improvement can be found in the carbon metabolism system of Beijing and Tianjin, Hebei province still faces intensely competitive ecological relationships between industrial land and other land use, and has a relatively low mutualism index. It is suggested that integrated land use planning, strict cultivated land protection policies, and proper ecological compensation mechanism are the key measures to facilitate the sustainable development of the BTH urban agglomeration. • A temporal-spatial evolution of carbon metabolism in the BTH urban agglomeration is presented. • The impacts of land use change on urban carbon metabolism system are investigated. • Ecological relationships between land-use changes are explored based on the ENA method. • Industrial transfer and expanded transportation exacerbate carbon metabolism imbalance. [ABSTRACT FROM AUTHOR]

Sand and gravel aggregate (SGA) transportation accounts for over 30% of the freight volume in China, which is greater than that of any other cargo; low-carbon development can effectively promote the decarbonization of freight transportation. This study presents a four-step evaluation method to assess CO 2 emission reductions in freight transportation; the proposed method helps determine the relationship between the policy, CO 2 emission reductions, demand, and mode market share. Using Beijing as a case study, this paper estimates the potential of reducing CO 2 emissions from SGA transportation under various scenarios. The scenarios are set based on the avoid, shift, and improve strategies; the results of the Beijing case indicate that the CO 2 emission for SGA transportation is 920.86 kt, which is approximately 1% of the total CO 2 emissions in Beijing. The maximum reductions in CO 2 emissions that can be achieved using the avoid, shift, and improve strategies are 0.92 kt (0.1% of total), 560.52 kt (60.9% of total), and 78.59 kt (8.5% of total), respectively. The shift strategy is confirmed to be the most realistic and cost-effective approach for reducing CO 2 emissions from SGA transportation. In addition, the implementation of subsidy policies is discussed. Marginal abatement costs under the subsidy scenarios are higher than 224 CNY/t, which is higher than the price in the Chinese carbon trading market. • We evaluated CO 2 emission of aggregate transportation in Beijing at the OD level. • CO 2 emission reductions of the avoid, shift, and improve strategies were tested. • Shift strategy performed the best in reducing CO 2 emission. • Avoid and improve strategies can reduce CO 2 emission; but the effects were limited. • Subsidizing rail transport reduced more emission than subsidizing electric trucks. [ABSTRACT FROM AUTHOR]

Particulate matter (PM) adversely affects air quality, human health and the climate, and it is more prevalent in urban areas. Few efforts have been made to quantify the impact of trade on PM concentrations in an urban economy. This paper presents an analysis of the impacts of domestic and international trade on PM emissions in Beijing using a three-scale input–output model, supported by the national and global embodied energy-related PM 2.5 , PM 10 and TSP (total suspended particulate) emission intensities. The results found that the total energy-related PM 2.5 , PM 10 and TSP emissions (production-based) in Beijing were 106 Gg, 163 Gg and 347 Gg, respectively, in 2010. Of these amounts, 48% (51 Gg, 74 Gg and 146 Gg, respectively) was associated with local demand, 42% (44 Gg, 73 Gg and 168 Gg, respectively) was associated with domestic exports, and 10% (11 Gg, 16 Gg and 33 Gg, respectively) was associated with international exports. From a consumption perspective, Beijing’s PM 2.5 , PM 10 and TSP emissions were more than double the production-based PM emissions. Approximately 75% (172 Gg, 311 Gg and 786 Gg, respectively) of the consumption-based PM emissions were domestically outsourced to other provinces, primarily via the import of metal (32 Gg, 58 Gg and 151 Gg), construction (26 Gg, 36 Gg and 91 Gg) and chemical products (16 Gg, 30 Gg and 75 Gg), and 3% (8 Gg, 10 Gg and 24 Gg, respectively) of consumption-based PM emissions were outsourced abroad. Our results indicate that domestic trade plays a dominant role in Beijing’s PM 2.5 emissions. These findings suggest that more national and sub-national government should co-ordinate design and implement effective mechanisms to alleviate urban air pollution because of the significant effects of interprovincial and international trade on local emissions. [ABSTRACT FROM AUTHOR]