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Currently, mitigation of persistent severe O3 pollution is the key for further improving the air quality in the Beijing-Tianjin-Hebei (BTH) region, China. The source contributions and transboundary transport of O3 during pollution episodes are closely related to weather conditions. The effective reduction in emissions to control O3 pollution under typical local atmospheric circulation conditions highly correlated with continuous pollution processes in the North China Plain (NCP) is rarely reported. In this study, a sensitive area in the BTH region was identified based on the analysis of the diurnal evolution features of local atmospheric circulation and the distribution characteristics of anthropogenic emissions in the NCP region. Multiple emission reduction scenarios were designed to explore the impacts of hotspot anthropogenic emissions in this sensitive area on O3 pollution formation during a regional prolonged O3 pollution episode from 30 August to 6 September 2019. Compared to large-scale anthropogenic emission control across the NCP region, a smaller emission reduction and much larger O3DM (the daytime mean ozone concentration, from 10 a.m. to 5pm) reduction were obtained through emission control in the sensitive area. The results also indicated that anthropogenic emission hotspots in this sensitive area play a decisive role in O3 photochemical formation chemistry across the whole BTH region with high emissions. The actual impact of hotspot anthropogenic emissions originating in the BTH region was not limited to its locality but occurred within a certain wide range, with a relatively significant contribution to O3DM ranging from approximately 20-80 μg/m3 in most of the plain area, accounting for approximately 15%∼40% of O3DM. Among all anthropogenic sources, the industry is the most important contributor to O3 formation, and traffic is the second most important contributor. In terms of regional emission control, it is suggested that under extremely unfavorable weather conditions, the BTH government should focus on local emission reduction, particularly in the industrial source category, and it should simultaneously consider the synergistic impact between the industry and traffic to maximize the effectiveness of control policies to achieve long-term ozone reduction.

Currently, most regional thermal environment (RTE) studies in urban agglomerations focus on developing countries, especially China. However, there is still a lack of comparative studies on the RTEs of urban agglomerations between China and other developed countries, such as the United States. This paper used the Beijing-Tianjin-Hebei (BTH) agglomeration in China and Boswash (the highly urbanized area extending from Boston to Washington) in the United States as examples to investigate the differences in land development patterns, RTEs and their relationship between the agglomerations of China and America. The results showed that the land development patterns of BTH and Boswash were different, as evidenced by the spatial pattern of land development intensity (LDI) and impervious surface configuration. In terms of the RTE, the sub-high land surface temperature (LST) zones were aggregated in a large and compact patch in central and northern BTH. However, the sub-high zones of the cities in Boswash were relatively separate. Moreover, the land development pattern of Boswash showed a stronger relationship with the RTE than that of BTH did. Global Moran's I between the LDI and LST in Boswash was higher than that in BTH. In addition, the correlation between impervious surface configuration and LST in Boswash was stronger than that in BTH, and this correlation was more controlled by LDI in Boswash. This study also indicated that BTH should change the land development pattern to prevent the further expansion of aggregated sub-high LST zones and control the proximity of high LST zones in cities in central and southern BTH, however, Boswash should adopt some local heat management approaches (installing cool and green roofs and creating more green space) in the core areas to help reduce the very high temperatures in the already highly developed areas where the largest fraction of people live.

Rapid urbanization and the aggregation of human activities in cities have resulted in large amounts of anthropogenic heat (AH) emission, which affects urban climate. Quantifying and assessing the AH emission values accurately and analyzing their spatial distribution characteristics is important to understand the energy exchange processes of urban areas. In this study, the high spatial resolution anthropogenic heat flux (AHF) quantification and spatial distribution analysis were conducted using multi-source data in the Beijing-Tianjin-Hebei region (BTH region) of China. First, the AH emission in district and city level were estimated using inventory method based on energy consumption and socio-economic statistical data; Then, AHF spatial quantification models were constructed based on high spatial resolution nighttime light (NTL) data and Point of interests (POI) data, and 130 m × 130 m gridded AHF quantification result in BTH region was realized; Finally, the potential numerical and spatial distribution patterns of AHF were analyzed using various indicators including contribution rate and aggregation index. The results show that: (1) The parameterized index constructed based on NTL and POI data shows a strong correlation with AHF, with R2 ranging from 0.79 to 0.94 and a mean absolute error (MAE) value of 0.72 w·m−2, which can be applied to the quantification of gridded AHF values with high resolution. The highest total AHF in the study area is 214 w·m−2, and the average value is 2.24 w·m−2. (2) Considering the sources of AHF, industrial emission sources in BTH region contribute the most to the total AHF, but commercial building emission sources in Beijing have a higher contribution, which can reach 33.8%. (3) Different types of AHF have different spatial aggregation levels. Commercial building emission and human metabolic emission have the highest aggregation level, and transportation emission has the lowest aggregation level.

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.

Motivated by a need to evaluate the effectiveness of a campaign to alleviate the notorious air pollution in China's Beijing-Tianjin-Hebei (BTH) region, we outline a temporal statistical adjustment method which is demonstrated from several aspects on its ability to remove the meteorological confounding existed in the air quality data. The adjustment makes the adjusted average concentration temporally comparable, and hence can be used to evaluate the effectiveness of the emission reduction strategies over time. By applying the method on four major pollutants from 73 air quality monitoring sites along with meteorological data, the adjusted averages indicate a substantial regional reduction from 2013 to 2016 in PM2.5 by 27% and SO2 by 51% benefited from the elimination of high energy consumption and high polluting equipments and a 20.7% decline of the coal consumption, while average NO2 levels had been static with a mere 4.5% decline. Our study also reveals a significant increase in the ground O3 by 11.3%. These suggests that future air quality management plans in BTH have to be based on dual targets of PM2.5 and O3.

High energy conservation and emission reduction (ECER) requirements across industries in the Beijing–Tianjin–Hebei (BTH) region have been proposed along with the transformation of China’s economic development mode. However, the energy consumption rebound effect, as an important proxy for achieving sustainable low-carbon development, has not been adequately investigated across industrial enterprises in this area. This study adopts an alternative estimation model based on neoclassical economic theory to measure the energy rebound effect of industrial enterprises in the BTH region from 1996 to 2015. Four main results are obtained. First, the energy rebound effects in Beijing, Tianjin, and Hebei are significantly different in the temporal and spatial dimensions. Second, technological progress does not reduce energy consumption, and the local government must simultaneously consider technological progress, industrial structure, and policy formulation to achieve the ECER goals. Third, ECER policies combined with government administrative measures do not have an impact on reducing energy consumption. Fourth, in the process of implementing the integration development of the BTH region, Hebei faces greater pressure to attain ECER goals in the future than the other regions. This study provides suggestions based on these derived results from the perspectives of market-oriented measures, management factors, development mode, and regional cooperation to achieve the sustainable development of the BTH region.

As the space carrier of the construction of ecological civilization, land’s green and efficient utilization is an important guarantee for realizing national sustainable development. Based on traditional land evaluation, this paper scientifically defines the green land use, puts land as one of the production factors, and brings energy consumption, environmental pollution, etc. into the input-output system to measure the green land utilization efficiency of the urban construction land of Beijing-Tianjin-Hebei Urban Agglomeration from 2006 to 2016. The study shows that the overall efficiency variation of the urban agglomeration is related with the land and environment policies. Efficiency of 2016 is higher than that of 2006, and energy and environment are the principal factors affecting the green land use. The efficiency of each city is positively correlated with its economic development, negatively correlated with the construction land expansion. Efficiency gaps in different cities are expanding. Th...

An inventory of anthropogenic emissions of twelve hazardous trace elements (HTEs): Hg, As, Se, Pb, Cd, Cr, Ni, Sb, Mn, Co, Cu and Zn, in the Beijing-Tianjin-Hebei (BTH) region of China is developed for 1980–2012 by using inter-annual dynamic emission factors, which are determined with S-shaped curves. Our results indicate that the BTH regional total emissions of twelve HTEs have rapidly increased from 2190.0 tons in 1980 to 8704.6 tons in 2012. Coal combustion by industrial boilers, ferrous metal smelting, glass production and brake wear are identified to be the primary sources of regional HTE emissions. Beijing is the largest Sb emitting city with about 20.0% of regional total emission. However, for other eleven HTE emissions, Tangshan represents as the highest emitting city, accounting for about 15.3–35.9% of the BTH totals. The peak HTE emission intensities (emissions per square kilometer) are mainly distributed over the grid cells of central and southeastern of the BTH region, especially for the urban and rural-urban border zones of cities. Generally, monthly variations of HTE emissions in the BTH region exhibit seasonal peak to valley characteristics. The overall uncertainties of the newly developed inventory are estimated to be from −35.7% to 36.4%. Finally, integrated countermeasures for emission reduction of HTEs are proposed.

Based on framework of urban metabolism, we constructed the energy metabolism networks of the Jing-Jin-Ji region at two scales: urban and sectoral scale. We used ecological network utility analysis to study mutualism and synergism indices for networks at two scales. Analysis results provide theoretical and empirical support for the development of policies designed to promote healthy development of Jing-Jin-Ji region.

From the development of modern transportation to the current era of high-speed transportation networks, the Beijing-Tianjin-Hebei (BTH) region has always played a national leading role in land transportation development of China. In order to explore the long-term evolutionary characteristics of land transportation in the BTH region, this paper utilized a temporal scale of 100 years to systematically interpret the development process of the land transportation network. Taking 13 cities within the BTH region as research anchor cities, we took into account “leaping” mode of transportation in order to investigate the evolution of accessibility. Our research shows the following results: (1) The land transportation network in the BTH region has undergone five stages of development: the initial period of modernization (1881–1937); the period of stagnation of transportation development (1937–1949); the network expansion period (1949–1980); the period of trunk construction (1980–1995), and the period of high-speed transportation network development (1995–present). The network structure centered around Beijing has existed from the outset of modern transportation development. (2) The accessibility spatial pattern of land transportation in BTH region has evolved from expansion along traffic corridors to the formation of concentric circles. The stratified circular structure of transportation in anchor cities has gradually developed into a contiguous development pattern. (3) There are clear hierarchical differences in the transportation structures of anchor cities. Beijing has always been at the top of this hierarchy, while the hierarchical position of Zhangjiakou has fallen noticeably since 1949. The Beijing-Tianjin region was the first region to form a short-duration transportation circle structure, while the transportation advantages of the central part of Hebei Province, which is located in the center of the BTH transportation region, have yet to be realized.

Based on joint-innovation patent data from 2000 to 2016 in the Beijing–Tianjin–Hebei region of China, the purpose of this paper is to analyze how technological proximity affects university–industry...

Water crisis is prominent in the Beijing-Tianjin-Hebei region, therefore, the internal relations between water utilization changes and socioeconomic development must be urgently analysed. Based on analyses of the spatiotemporal characteristics of total water utilization, the factors that influenced changes in industrial water utilization in the Beijing-Tianjin-Hebei region from 2003 to 2016 were studied using a factor decomposition model. The results show that the scaling effect (SCE) increased water utilization by 31.78 billion m3 over those 13 years and was the only driving effect that caused industrial water utilization to increase. The structural effect (STE) and technological effect (TEE) reduced industrial water utilization by 14.93 and 20.44 billion m3, respectively. The TEE was the main reason for the decrease in industrial water utilization in Beijing, accounting for a reduction of 96.5% in total industrial water utilization. The STE was stronger than TEE in Tianjin, with associated decreases of 94.65% and 90.1% in total industrial water utilization, respectively. In Hebei, the STE and TEE reduced total industrial water utilization by 60.23% and 85.46%, respectively. Adjusting the industrial structure and promoting water-saving technology are efficient methods of alleviating the water shortage in the study area.

As one common precursor for both PM2.5 and O3 pollution, NO x gains great attention because its controls can be beneficial for reducing both PM2.5 and O3 . However, the effectiveness of NO x controls for reducing PM2.5 and O3 are largely influenced by the ambient levels of NH3 and VOC, exhibiting strong nonlinearities characterized as NH3 -limited/ NH3 -poor and NO x -/VOC-limited conditions, respectively. Quantification of such nonlinearities is a prerequisite for making suitable policy decisions but limitations of existing methods were recognized. In this study, a new method was developed by fitting multiple simulations of a chemical transport model (i.e., Community Multiscale Air Quality Modeling System, CMAQ) with a set of polynomial functions (denoted as “pf-RSM”) to quantify responses of ambient PM2.5 and O3 concentrations to changes in precursor emissions. The accuracy of the pf-RSM is carefully examined to meet the criteria of a mean normalized error within 2 % and a maximal normalized error within 10 % by using 40 training samples with marginal processing. An advantage of the pf-RSM method is that the nonlinearity in PM2.5 and O3 responses to precursor emission changes can be characterized by quantitative indicators, including (1) a peak ratio (denoted as PR) representing VOC-limited or NO x -limited conditions, (2) a suggested ratio of VOC reduction to NO x reduction to avoid increasing O3 under VOC-limited conditions, (3) a flex ratio (denoted as FR) representing NH3 -poor or NH3 -rich conditions, and (4) enhanced benefits in PM2.5 reductions from simultaneous reduction of NH3 with the same reduction rate of NO x . A case study in the Beijing–Tianjin–Hebei region suggested that most urban areas present strong VOC-limited conditions with a PR from 0.4 to 0.8 in July, implying that the NO x emission reduction rate needs to be greater than 20–60 % to pass the transition from VOC-limited to NO x -limited conditions. A simultaneous VOC control (the ratio of VOC reduction to NO x reduction is about 0.5–1.2) can avoid increasing O3 during the transition. For PM2.5 , most urban areas present strong NH3 -rich conditions with a PR from 0.75 to 0.95, implying that NH3 is sufficiently abundant to neutralize extra nitric acid produced by an additional 5–35 % of NO x emissions. Enhanced benefits in PM2.5 reductions from simultaneous reduction of NH3 were estimated to be 0.04–0.15 µ g m −3 PM2.5 per 1 % reduction of NH3 along with NO x , with greater benefits in July when the NH3 -rich conditions are not as strong as in January. Thus, the newly developed pf-RSM model has successfully quantified the enhanced effectiveness of NO x control, and simultaneous reduction of VOC and NH3 with NO x can assure the control effectiveness of PM2.5 and O3 .

The northeastern China frequently experiences severe aerosol pollution in winter under unfavorable meteorological conditions. How and to what extent the meteorological factors affect the air quality there are not yet clearly understood. Thus, this study investigated the impacts of synoptic patterns on the aerosol transport and planetary boundary layer (PBL) structure in Shenyang from 1 to 3 December 2016, using surface observations, sounding measurements, satellite data, and three-dimensional simulations. Results showed that the aerosol pollution occurred in Shenyang was not only related to the local emissions, but also contributed by trans-boundary transport of aerosols from the Beiijng-Tianjin-Hebei (BTH) region. In the presence of the westerly and southwesterly synoptic winds, the aerosols emitted from BTH could be brought to Shenyang. From December 2 to 3, the aerosols emitted from BTH accounted for ∼20% of near-surface PM2.5 in Shenyang. In addition, the large-scale synoptic forcings could affect the vertical mixing of pollutants through modulating the PBL structure in Shenyang. The westerly and southwesterly synoptic winds not only brought the aerosols but also the warmer air masses from the southwest regions to Shenyang. The strong warm advections above PBL could enhance the already existing thermal inversion layers capping over PBL in Shenyang, leading to the suppressions of PBL. Both the trans-boundary transport of aerosols and the suppressions of PBL caused by the large-scale synoptic forcings should be partly responsible for the poor air quality in Shenyang, in addition to the high pollutant emissions. The present study revealed the physical mechanisms underlying the aerosol pollution in Shenyang, which has important implications for better forecasting and controlling the aerosols pollution.

Changes in precipitation have a large effect on human society and are of primary importance for many scientific fields such as hydrology, agriculture and eco-environmental sciences. The present study intended to investigate the spatio-temporal characteristics of precipitation in Beijing-Tianjin-Hebei (BTH) region by using 316 meteorological stations during the period 1965–2014. Geographical Weighted Regression (GWR) method and High Accuracy Surface Modeling (HASM) method were applied to produce the precipitation patterns at different time scales. Mann-Kendall (MK) statistical test was applied to analyze the precipitation temporal variations. Results indicated that annual precipitation over the past 50 years appeared to be a non-periodic oscillation phenomenon; the number of wet years was approximately the same as that of dry years; significant positive trends were observed in spring during 1978–2014 and summer during 1996–2014; on the whole, precipitation in May, June, September, and December showed increasing trends at the 95% confidence level; and significant positive trends were also identified in July during 2000–2013 and August during 1997–2010, while slight decreasing trends were observed in February and November. Summer (June, July, and August) was the wettest season, accounting for 68.73% of annual totals in BTH. In general, northeastern BTH received the highest range of precipitation while northwestern area had the lowest. It was found that precipitation variation in this region had been closely linked to latitude, Digital Elevation Model (DEM), distance to the sea, and urbanization rate. In addition, land use played an important role in the decadal precipitation changes in BTH.

Satellite-derived aerosol optical depth (AOD) has been proven effective for estimating ground-level particles with an aerodynamic diameter

China's Beijing-Tianjin-Hebei (BTH) region suffers from the country's worst air pollution. The problem has caused widespread concern both at home and abroad. Based on long-term and massive data mining of PM2.5 and PM10 concentration, we found that these pollutants showed similar variations in four seasons, but the most severe pollution was in winter. Through cluster analysis of the winter daily average concentration (DAC) of the two pollutants, we defined regions with similar variations in pollutant concentrations in winter. For the most polluted cities in BTH, the relationship between correlation coefficients for winter DAC and the distance between cities revealed that PM2.5 has regional, large-scale characteristics, with concentrated outbreaks, whereas PM10 has local, small-scale characteristics, with outbreaks at multiple locations. By selecting the key cities with the strongest linear relationship between the pollutant's DAC of each city and the daily individual air quality index values of the BTH region and through cluster analysis on the correlations between the pollutant DACs of the key cities, we defined regional divisions suitable for Joint Prevention and Control of Atmospheric Pollution (JPCAP) program to control PM2.5 and PM10. Comprehensively considering the degree of influence of regional atmospheric pollution control (RAPC) on air quality in BTH, as well as the elasticity and urgency of RAPC, we defined the control grades of the JPCAP regions. We found both the regions and corresponding control grades were consistent for PM2.5 and PM10. The thinking and methods of atmospheric pollution control we proposed will have broad significance for implementation of RAPC in other regions around the world.

Under the background of China’s rapid urbanization, study on comparative analysis of the spatial structure of urban agglomerations between China and the US can provide the policy proposals of space optimization for the Chinese government. Taking the Beijing-Tianjin-Hebei (BTH) and Boswash as study area, we mapped the subpixel-level impervious surface coverage of the BTH and Boswash, respectively, from 1972 to 2011. Further, landscape metrics, gravitational model and spatial analysis were used to analyze the differences of the spatial structures between the BTH and Boswash. The results showed that (1) the area of the impervious surface increased rapidly in the BTH, while those remained stable in the Boswash. (2) The spatial structure of the BTH experienced different periods including isolated cities stage, dual-core cities stage, group cities stage and network-style cities stage, while those of the Boswash was more stable, and its spatial pattern showed a “point-axis” structure. (3) The spatial pattern of high-high assembling regions of the impervious surface exhibited a “standing pancake” feature in the BTH, while those showed a “multi-center, local aggregation and global discrete” feature in the Boswash. (4) All the percentages of the impervious surface of ecological, living, and production land of the BTH were higher than those of the Boswash. At last, from the perspective of space optimization of urban agglomeration, the development proposals for the BTH were proposed.

A routine air quality data assimilation (DA) system was established at the China National Environmental Monitoring Center (CNEMC) based on the optimal interpolation (OI) method. The surface observations from more than 1,400 stations across China were assimilated into a real-time air quality forecast system with three nested domains. The initial conditions of NO2, SO2 and PM2.5 in the three domains were optimized by the data assimilation system. The impact of the data assimilation on the real-time PM2.5 forecast over the Beijing-Tianjin-Hebei (BTH) Region during the heavy haze season of 2015 was evaluated. The results show that the DA can significantly improve real-time PM2.5 forecasts, reducing the root mean square error (RMSE) by 23%, 8.2% and 4.8% in the forecasts of the first, second and third day, respectively. The mean fractional bias and the mean fractional error of the forecast were reduced from 50.9% and 70.67% to 40% and 62.3%, respectively, and the performance changed from “criteria” to approaching “goal” (as defined by Boylan and Russell, 2006). Additionally, increasing the assimilation frequency can improve the DA system performance for real-time forecasts. As can be seen from the various cases studied here, the improvement in data assimilation is more significant when the bias of the model is higher and there is still much room for correction. The results also show a rapid decay of the DA effects on the PM2.5 forecast, which highlights the limitations of the current routine data assimilation system in which only initial conditions are optimized. Further improvements in the data assimilation system with meteorological data assimilation and chemical parameter optimization are needed.

Sixty-four bottom ash (BA) samples from indoor burning of eight bio-fuels (BFs) including cotton (COT), corn (COR), millet (MIL), soybean (SOY), sorghum (SOR) and sesame (SES), firewood walnut (WAL), and corn cob (COC) were collected across the Beijing-Tianjin-Hebei (BTH) region. Each BA was divided into five differently sized parts for the analysis of eighteen PAHs using the GC/MS system. The Σ18PAHs values for all the BAs varied from 65.0 ± 10.6 to 1310 ± 129 ng g–1. SOR had the highest PAH level, and COC produced the lowest level. The Σ18PAHs for SOY, WAL, COT, COR, COC, and SES were negatively correlated with the BA sizes. The NA, PHE, ACL, AN, FA, PY, FL, and AC dominated in all the BAs except for SES. All the BAs were dominated by 2, 3-ring PAHs. The PAH profiles for differently sized BAs within MIL, SOR, COC, COR, and SES were similar based on lower coefficient of divergence values, while the other three BFs did not exhibit this trend. All the BF pairs except for SOR vs. SES and COC vs. COR had the different PAH profiles. No series of coincident diagnostic ratios (DRs) could represent all BFs based on their significantly varied DRs. AN/(AN + PHE) and BA/BgP might be used in identification of combustion sources of different types of BFs. SOR and SES had higher potential toxicity risk based on higher TEQ, BaPE, and CPAHs values. BgF and BgP were the indicatory PAHs for SOY, MIL, COR, SOR, and COC, while they were AC and FL for the remaining three BFs.

The Beijing-Tianjin-Hebei (BTH) region, which has a resource-dependent economy dominated by clusters of heavy industries, has long borne the highest PM2.5 pollution levels in China, prompting serious concerns about the region's disease burden. Pollution-intensive industries in the BTH region not only meet local consumer demands but also those of other places via the supply chain. In the present study, we combined a multi-region input-output model with adjoint source sensitivity modeling technique at a high resolution (0.25° × 0.3125°) to apportion PM2.5-related mortality risks in the BTH to consuming areas and sectors. The model predicted that exposure to ambient PM2.5 caused 0.12 million premature deaths (95% confidence interval: 0.08-0.15) in the BTH region in 2013. The adjoint source sensitivity results showed that only 46% of the total premature deaths were attributable to local consumption. The top contributors of local consumption were rural households and the agricultural sector in Hebei, and service sector in Beijing. Consumption of other domestic regions and international export accounted for 25% of the total premature deaths in the BTH, mainly to support consumption of manufacturing and construction products of these outer regions. Atmospheric transport of pollutants, mainly from the surrounding areas, accounted for the remaining 29% of total deaths in BTH. Our findings underline the consumption-based driven force of BTH's pollution and associated health impacts, which may facilitate the joint control actions among the BTH region and its surrounding areas from a comprehensive perspective.

Ammonia (NH3) discharged from agricultural activities to the atmosphere plays a crucial role in the formation of secondary inorganic aerosols. This study analyzed the temporal-spatial development of agricultural NH3 emissions from 2000 to 2018 in the Beijing–Tianjin–Hebei (BTH) region and assessed the effects of reducing PM2.5 by removing agricultural NH3 using an air quality model. The results showed that the interannual agricultural NH3 emissions in the BTH region exhibited a stairs trend from 2000 to 2018, with an average of 971.63 Gg. In particular, agricultural NH3 emissions in the BTH region reached a maximum in summer when the temperature was high and were more concentrated in the southern plains compared to the northern areas. Under the reduction scenario (RS), the agricultural NH3 emissions in the BTH region in 2015, 2016, 2017, and 2018 were reduced by 2.95%, 4.10%, 18.75%, and 10.21%, resulting in a reduction of 0.5%, 0.5%, 2.5%, and 1.2% of annual mean PM2.5 concentration, respectively, compared with the baseline scenario (BS). Furthermore, agricultural NH3 emissions contributed 12.6, 12.1, 11.9, and 11.3 μg m−3 to PM2.5 concentrations in 2015, 2016, 2017, and 2018 under the zero-emission scenario (ZS), respectively. However, the contribution rates exhibited a slightly increasing trend from 20.5% in 2015 to 24.6% in 2018. These findings could provide a new understanding of agricultural NH3 emission trends and their impacts on PM2.5 concentration based on actual NH3 mitigation ratios in recent years, thereby guiding the formulation of future control strategies.

In the present study, a persistent heavy haze episode from 13 to 20 January 2014 in Beijing–Tianjin–Hebei (BTH) is simulated using the WRF-CHEM model through ensemble simulations to investigate impacts of meteorological uncertainties on the haze formation. Model results show that uncertainties in meteorological conditions substantially influence the aerosol constituent simulations at an observation site in Beijing, and the ratio of the ensemble spread to the ensemble mean (RESM) exceeds 50 %. The ensemble mean generally preforms well in reproducing the fine particles' (PM2.5) temporal variations and spatial distributions against measurements in BTH. The meteorological uncertainties do not alter the PM2.5 distribution pattern in BTH principally or dominate the haze formation and development, but remarkably affect the simulated PM2.5 level, and the RESM for the simulated PM2.5 concentrations can be up to 30 % at the regional scale. In addition, the rather large RESM in PM2.5 simulations at the city scale also causes difficulties in evaluation of the control strategies. Therefore, our results suggest that the ensemble simulation is imperative to take into account the impact of the meteorological uncertainties on the haze prediction.

We developed a high-resolution Beijing-Tianjin-Hebei (BTH) regional air pollutants emission inventory for the year 2013. The inventory was established using a bottom-up approach based on facility-level activity data obtained from multiple data sources. The estimates from the BTH 2013 emission inventory show that the total emissions of SO2, NOX, PM2.5, PM10, CO, NMVOC, NH3, BC, and OC were 2,305, 2,686, 1,090, 1,494, 20,567, 2,207, 623, 160, and 254 Gg, respectively. The industry sector is the largest emissions source for SO2, NOX, PM2.5, PM10, CO, and NMVOC in the BTH region, contributing 72.6%, 43.7%, 59.6%, 64.7%, 60.3%, and 70.4% of the total emissions, respectively. Power plants contributed 11.8% and 23.3% of the total SO2 and NOX emissions, respectively. The transportation sector contributed 28.9% of the total NOX emissions. Emissions from the residential sector accounted for 31.3%, 21.5%, 46.6% and 71.7% of the total PM2.5, NMVOC, BC and OC emissions, respectively. In addition, more than 90% of the total NH3 emissions originate from the agriculture sector, with 44.2% from fertilizer use and 47.7% from livestock. The spatial distribution results illustrate that air pollutant emissions are mainly distributed over the eastern and southern BTH regions. Beijing, Tianjin, Shijiazhuang, Tangshan and Handan are the major contributors of air pollutants. The major NMVOC species in the BTH region are ethylene, acetylene, ethane and toluene. Ethylene is the biggest contributor in Tianjin and Hebei. The largest contributor in Beijing is toluene. There is relatively low uncertainty in SO2 and NOX emission estimates, medium uncertainty in PM2.5, PM10 and CO emission estimates, and high uncertainties in VOC, NH3, BC and OC emission estimates. The proposed policy recommendations, based on the BTH 2013 emission inventory, would be helpful to develop strategies for air pollution control.

To investigate the interannual variations of particulate matter (PM) pollution in winter, this paper examines the pollution characteristics of PM with aerodynamic diameters of less than 2.5 and 10 μm (i.e., PM2.5 and PM10), and their relationship to meteorological conditions over the Beijing municipality, Tianjin municipality, and Hebei Province—an area called Jing–Jin–Ji (JJJ, hereinafter)—in December 2013–16. The meteorological conditions during this period are also analyzed. The regional average concentrations of PM2.5 (PM10) over the JJJ area during this period were 148.6 (236.4), 100.1 (166.4), 140.5 (204.5), and 141.7 (203.1) μg m–3, respectively. The high occurrence frequencies of cold air outbreaks, a strong Siberian high, high wind speeds and boundary layer height, and low temperature and relative humidity, were direct meteorological causes of the low PM concentration in December 2014. A combined analysis of PM pollution and meteorological conditions implied that control measures have resulted in an effective improvement in air quality. Using the same emissions inventory in December 2013–16, a modeling analysis showed emissions of PM2.5 to decrease by 12.7%, 8.6%, and 8.3% in December 2014, 2015, and 2016, respectively, each compared with the previous year, over the JJJ area.

The chemical composition of PM2.5 and cellular effects from exposure to fine aerosol extracts were studied for samples collected in Beijing, Tianjin, Shijiazhuang, and Hengshui, China in winter 2015. Effects of priority polycyclic aromatic hydrocarbons (PAHs) and their oxygenated derivatives (OPAHs) in PM2.5 on cell cultures were a major focus of the study. Total quantified PAHs and OPAHs at Shijiazhuang and Hengshui were higher than at Beijing and Tianjin, and benz(a)anthracene, chrysene and 1,8-naphthalic anhydride were the most abundant species. Exposure to PM2.5 extracts caused a concentration-dependent decline in cell viability and a dose-dependent increase in nitric oxide production. Two cytokines, tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6), also increased when A549 test cells were exposed to PM2.5 extracts. PAHs and OPAHs in PM2.5 can potentially cause cell damage and induce cytotoxicity and pro-inflammatory responses: benzo(a)anthracene-7,12-dione was highly correlated with NO production, dibenz(a,h)anthracene and 1,4-chrysenequinone were correlated with TNF-α production, and 1-naphthaldehyde was significantly correlated with IL-6 production. The study provides a new approach for evaluating relationships between air-quality and cell toxicity with respect to specific chemicals.

Mosaic approach, with certain number of tiles representing land use (LU) types in each grid cell, had been implemented into WRF-Noah model. Previous studies found mosaic approach had a better performance on meteorological parameters than only considering dominant LU in dominant approach. In this study, the impacts of mosaic approach on meteorological parameters and air quality were investigated in WRF-CMAQ over Beijing-Tianjin-Hebei (BTH) region in China in 2020. Results showed that mosaic approach improved the simulation results of WS10 (surface wind speed at 10 m), T2 (temperature at 2 m), and RH (relative humidity) especially in nighttime in winter and were available for all stations with different percent of urban area. “MOS_TOPO” scenario, which coupled with mosaic approach and “topo-wind” schemes, obtained best simulation results of WS10 and T2 in January among six scenarios, with the lower average Root Mean Square Error of WS10 (1.18 m/s) and Mean Bias of T2 (0.55 °C) for all stations. Meanwhile, mosaic approach obtained lower |NMB| of PM2.5 than dominant approach in more than 69% cities in BTH region. Cities in southern Hebei province, especially Xingtai city, were identified as the most sensitive area for PM2.5 simulation affected by mosaic approach. Although the mosaic approach has improved the simulation results of meteorological parameters, especially the nighttime simulation results of WS10, there is still some deviation in the simulation results of PM2.5. Accurate emission inventory, suitable physics option in numerical weather model and rational chemical mechanism in air quality model are the important factors for WRF-CMAQ.

Urban agglomeration is the most obvious regions in the Chinese rapid urban land expansion. The developed urban agglomerations in China (i.e., Beijing-Tianjin-Hebei (BTH), Yangtze River Delta (YRD) and Guangdong–Hong Kong–Macau Greater Bay Area (GBA)) have entered a suburban urbanization period; however, it is not clear whether the urbanization on low-slope hilly regions (hillside urbanization) exist in these urban agglomerations. In this study, we proposed a quantification framework to detect hillside urbanization with multiple earth observation data and socio-economic data and further compared their spatiotemporal patterns from 2007 to 2017 in these three urban agglomerations. The results showed: (1) the urban area of BTH, YRD and GBA has expanded by 1.82, 2.37 and 1.53 times, respectively; (2) widespread hillside urbanization regions were found in BTH (475.82 km2), YRD (440.41 km2) and GBA (298.14 km2); (3) GBA had the largest hillside urbanization rate (10.55%), followed by BTH (6.33%) and YRD (3.18%); (4) the hillside urbanization of BTH, YRD and GBA provided accommodation and workplaces for about 1.05, 0.97 and 1.37 million people, respectively; and (5) the minimum and maximum high environmental cost (HEC) hillside urbanization rates were found in BTH (0.53%) and GBA (2.92%), respectively. Our findings may provide some new insights into urban sustainability.

The ecological security (ES) of urban agglomeration (UA) is an important guarantee and necessary condition for the sustainable development of the region and the country. Based on ecological system theory, this study established a new ES analysis framework for UA; a DPSIR-DEA model was built to evaluate ES from the perspective of system coordination, and Geodetector was used to explore the internal mechanism of the ES system. Taking the Beijing-Tianjin-Hebei urban agglomeration (BTH) as the empirical study area, the results showed that the ES of the BTH was generally insecure during 2005-2018, and it experienced a process in which it first improved, then declined, and finally recovered gradually. The spatial differentiation in the north-south, where the counties in the north have a better ES status than the southern counties, was further aggravated. The spatial autocorrelation analysis indicated that the spatial distribution of ES in BTH has a certain degree of aggregation, and the homogeneity of aggregation is enhanced. The main dominant factors affecting the ES in 2018 included the population density, proportion of construction land, ESV, PM2.5, fertilizer pollution and irrigation area ratio, and the interaction between factors was strengthened. Moreover, the results proved that human production and life play a leading role in the ES maintenance. The study also constructed the driving mechanism of ES and offered suggestions for the ES improvement of the BTH.

Under the background of China's energy conservation and emissions reduction pressure increasing, the Beijing-Tianjin-Hebei region have sharp contradiction in the economic development and energy consumption, transportation is important in the development of the national economy industry, is one of the biggest, the energy consumption of the carbon emissions of the second largest industry, the development of transportation will inevitably increase carbon emissions, for the transportation and the coordinated development of the carbon emissions. In this paper, the coupling coordination degree of the two was measured. Based on the data of Beijing-Tianjin-Hebei region from 2011 to 2018, the coupling model was used to measure the coupling coordination degree of the transportation system and the carbon emission system.Finally, it is concluded that the coupling coordination degree between transport and carbon emissions is the highest in Beijing, and the coupling coordination degree in Beijing-Tianjin-Hebei region is at the primary level or above. The variation trend of the coupling coordination degree in Beijing-Tianjin-Hebei region is firstly increased and then decreased, and there is a strong interaction between the two systems.

Phenolic environmental estrogens (PEEs) are ubiquitous in most rivers worldwide and may cause potential endocrine-disrupting effects in aquatic organisms. Three typical PEEs (bisphenol A, BPA; 4-tert-octylphenol,4-t-OP; and nonylphenol, NP) were investigated in the rivers of the Beijing-Tianjin-Hebei urban agglomeration, which is the most urbanized and industrialized area in North China. The target PEEs were detected in 100% of river water samples, and the concentrations ranged from 23 to 255 ng L-1. The concentrations of NP in most river sections were higher than those of BPA and 4-t-OP. The spatiotemporal variations in PEEs indicated that both domestic and industrial wastewater were main sources of PEEs in river water. In addition, rainfall runoff might be an important source of PEEs in the receiving waters, especially in the wet season. The ecotoxicological risk assessment of individual PEE revealed a moderate to high risk for aquatic organisms at most sampling sites. The mixture risk prediction based on the concentration addition method indicated a potential cumulative risk of PEEs in the study area, highlighting the importance of mixture risk assessment in the aquatic environment.

Urban parks, especially of large size, are highly beneficial for the physical, mental, and social well-being of urban residents by providing various recreational services. However, traditional methods and data sources to evaluate the park provision of recreation service take no account of actual user distribution and the interactions between cities. In this study, we used the density of mobile phone park check-ins and the average service radius of large urban parks, extracted from a massive volume of anonymized mobile phone signaling data, as two rapid indicators of the recreational use efficiency of large urban parks for 11 cities in the Beijing-Tianjin-Hebei (BTH) region. The results indicated the significant disparities among cities in terms of park visitation and service area in this region. Then, we conducted Hierarchical linear regression (HLR) models to explore the relationships between the two indicators and fourteen potential influencing city-level and park-specific factors for 206 sampled large urban parks. Park size was found to have the strongest and negative effect on the density of mobile phone check-ins of large urban parks, while the distance to the administrative center and park landscape shape index (LSI) was also negatively associated with the density of mobile park check-ins. Urban built-up area and the green coverage rate, positively associated with the density of mobile park check-ins, had a negative weight on the service radius of large urban parks. However, the number of POIs within the 1000m buffer and the overall park rating were positively associated with both the density of mobile park check-ins and the service radius of large urban parks. Our findings validated the trends of inter-city short trips on weekends and holidays, which necessitate a comprehensive plan on regional green space construction and sharing in city clusters, in order to improve both ecological and recreational services and benefit the health and well-being of urban residents at a larger scope.

China has entered an era of rapid high-speed railway (HSR) development and the spatial structure of urban agglomerations will evolve in parallel with the development and evolution of the spatial structure of the HSR network. In this study, we explore how the spatial structure of an HSR network evolves at regional and local scales. Existing research into HSR network structures has mostly been carried out at a regional scale, and has therefore failed to reveal the spatial connections within a city. In this work, we progress the science by exploring it at a local scale. To describe the HSR network more accurately, we use the dwell time to simulate the passenger flow between stations and use the simulated passenger flow as the network weight. We use complex network analysis to investigate the evolution of the network’s spatial structure. Our results present the evolution of station locations, of community structure, and of the locations of connections between stations at a regional scale, and also show how HSR network development within core cities has impacted structures and connectivity at a local scale. These results help us to understand the spatial structure of urban agglomerations and cities, and provide evidence that can be used to optimize the structure of the HSR network within regions and cities.

Due to the serious air pollution problem since 2012 in the Beijing-Tianjin-Hebei (BTH) region, the Chinese government launched the national strategy of the BTH Coordinated Development (the BTHCD). Meanwhile, energy transition is also a national strategy in the region. What is the relationship between these two strategies, and in particular how can energy transition serve BTHCD strategy? Firstly, the paper identifies the three main areas of the BTHCD strategy, namely, transportation integration, industrial upgrading and transfer, and ecological and environmental protection, and finds that the ultimate goals of the strategy are to promote economic growth and environment protection in the region. Then, an empirical study is conducted by using the BVAR model, which further shows the that energy transition and BTHCD are closely related. Finally, policy recommendations are made for enabling an energy transition that supports the BTHCD.

Beijing-Tianjin-Hebei region is not only the national key strategic development area, but also the main battlefield of low-carbon transformation. Beijing-Tianjin-Hebei region accounts for about 1/5 of the national carbon emissions, of which the power sector accounts for a large proportion of carbon emissions. Therefore, the research on the carbon reduction potential and contribution factors of Beijing-Tianjin-Hebei power sector is of great strategic significance to the achievement of BTH Coordinated Development and carbon neutralization strategy. Based on the comprehensive consideration of power generation, transmission, power consumption, power supply and other links, this paper constructs a bottom-up accounting model of CO2 emissions in power industry, and studies the main driving factors affecting carbon emissions by using LMDI method.

Lockdown measures to curtail the COVID-19 pandemic in China halted most non-essential activities on January 23, 2020. Despite significant reductions in anthropogenic emissions, the Beijing-Tianjin-Hebei (BTH) region still experienced high air pollution concentrations. Employing two emissions reduction scenarios, the Community Multiscale Air Quality (CMAQ) model was used to investigate the PM2.5 concentrations change in this region. The model using the scenario (C3) with greater traffic reductions performed better compared to the observed PM2.5. Compared with the no reductions base-case (scenario C1), PM2.5 reductions with scenario C3 were 2.70, 2.53, 2.90, 2.98, 3.30, 2.81, 2.82, 2.98, 2.68, and 2.83 μg/m3 in Beijing, Tianjin, Shijiazhuang, Baoding, Cangzhou, Chengde, Handan, Hengshui, Tangshan, and Xingtai, respectively. During high-pollution days in scenario C3, the percentage reductions in PM2.5 concentrations in Beijing, Tianjin, Shijiazhuang, Baoding, Cangzhou, Chengde, Handan, Hengshui, Tangshan, and Xingtai were 3.76, 3.54, 3.28, 3.22, 3.57, 3.56, 3.47, 6.10, 3.61, and 3.67%, respectively. However, significant increases caused by unfavorable meteorological conditions counteracted the emissions reduction effects resulting in high air pollution in BTH region during the lockdown period. This study shows that effective air pollution control strategies incorporating these results are urgently required in BTH to avoid severe pollution.

Evaluating the dynamics of sustainability for social-ecological systems (SESs) is fundamental for guaranteeing human well-being and achieving sustainable development goals (SDGs). Here, we develop a method to quantify and analyze the dynamics of sustainability for SESs based on the adaptive cycle framework and catastrophe theory. This method can effectively identify the important time points and areas that affect the dynamics of sustainability and is flexible for assessing various SESs. We applied this method to a typical SES, the Beijing-Tianjin-Hebei urban agglomeration (BTHUA). The results showed that the BTHUA experienced an overall rise in sustainability from 2000 to 2017. It has exhibited two adaptive cycles, among which 2006 and 2012 marked the release phases (i.e., the decrease in sustainability). The decline in the environmental subsystem and the increase in pollution from resource-based cities were major factors affecting the dynamics of sustainability in the BTHUA. Therefore, implementing place-based measures is encouraged to promote the sustainability of this urban agglomeration.

With the increasingly severe ozone pollution in the Beijing-Tianjin-Hebei region in recent years, NO2 photolysis has attracted our attention as the main source of tropospheric ozone generation. The photolysis rate of NO2 (J(NO2)) is of great importance for the quantification of photochemical ozone generation and photochemical pollution research, but its long-term changes in the Beijing-Tianjin-Hebei region remain unclear. An efficient reconstruction method for J(NO2) was established via simulations with the troposphere ultraviolet and visible radiation (TUV) model and the observations of J(NO2) and total ultraviolet (UV) radiation at a typical suburban site in the Beijing-Tianjin-Hebei region. We introduced the cloud modification factor in this method which improved the R2 value between the calculated and observed J(NO2) values from 0.64 to 0.94 over the TUV clear-sky simulation level. A long-term (2005–2019) J(NO2) dataset in Xianghe was reconstructed by applying this method. The annual mean J(NO2) value reached 3.5*10−3 s−1 from2005 to 2019. The annual mean J(NO2) value fluctuated slightly from 2005 to 2012 but increased evidently in the last 7 years. The increase rates of the annual mean J(NO2) value and O(3P) generation via NO2 photolysis were 1.3*10−4 s−1 per year and 1.1*10−3 ppb•s−1 per year, respectively, from 2013 to 2019. From 2005 to 2019, J(NO2) exhibited the sharpest increasing trend in summer, but increased the least in spring. The monthly mean J(NO2) value was the highest in May and the lowest in November. Our results demonstrated that to control the ozone concentration in the Beijing-Tianjin-Hebei region, we must pay more attention to the reduction in volatile organic compounds (VOCs) under the year-by-year increase in ambient J(NO2).

Regional transport is one of the major causes of severe haze pollution in the Beijing–Tianjin–Hebei (BTH) region. However, the process of pollutant transport and the specific mechanisms that affect haze pollution in the BTH region remain unclear. In this study, the WRF-Chem model was used to quantify the contribution of regional transport to a severe pollution event over the BTH region that occurred between October 29 and November 6, 2015. The results show that the regional transport of pollutants from the area south of the BTH region, which was induced by synoptic forcing and topographic effects, contributed up to 70% of the PM2.5 concentration in the BTH region. The peak PM2.5 concentration closely corresponded to a light southerly wind, high relative humidity, low planetary boundary layer height, and weak turbulent kinetic energy. The pollutants derived from regional transport were located mainly at an altitude of 0.5–1.5 km during the accumulating stage and at 0–3 km during the severely polluted stage, which reflects mainly the height of the inversion layer and the strength of the wind, whereas pollution derived from local emissions was restricted mainly to the near-surface layer (

In order to explore the impact of external environmental factors on the efficiency of logistics industry in Beijing Tianjin Hebei region, this paper uses Three-stage DEA method to study the efficiency of logistics industry in Beijing Tianjin Hebei region from 2013 to 2017. The results show that the overall logistics efficiency of Beijing Tianjin Hebei region is in a good state, but it does not reach the optimal state. After the adjustment, the pure technical efficiency and scale efficiency have obvious changes, which indicates that the external environmental factors such as the consumption level of residents, the total amount of telecommunications business and the total retail sales of regional social consumer goods have a significant impact on the efficiency of the logistics industry, Relevant departments can put resources in a targeted way to promote the efficiency of Beijing Tianjin Hebei logistics industry.

Air pollution presents one of most significant environmental issues in China, especially in the Beijing-Tianjin-Hebei (Jing-Jin-Ji) urban agglomeration. With the release of “The Outline of Coordinated Development for Beijing-Tianjin-Hebei region”, air quality in the Jing-Jin-Ji urban agglomeration has drawn wide concern. This study aims to provide a better understanding of inter-regional and sectoral linkages of air pollutants emissions and to identify key sectors that contribute to the transfer of embodied emissions in Beijing-Tianjin-Hebei region of China. A modified inter-regional and sectoral model was developed in this study for embodied emission flows based on the Multi-region input-output table. According to this model, transfer patterns of embodied air pollutant emissions (SO 2 , Soot, Dust and NO x ) flows in Jing-Jin-Ji urban agglomeration were analyzed. Similarly, the driving forces of the flows were examined. Results show that the transfer pattern of the most significant NTE flow was the same for SO 2 (18.8 kt), Soot (26.3 kt), Dust (12.8 kt) and NO x (29.9 kt), i.e. from the Nonmetal Products sector of Hebei province to the Construction sector of Beijing. This flow accounted for 35.7%, 45.5%, 36.7%, 42.0% of the total embodied emissions of SO 2 , Soot, Dust, NO x from Hebei province to Beijing respectively. Similarly, this study revealed that the contribution of Scale effect, Intensity effect and Structure effect was about 40%, 40% and 20% for the NTE from Hebei province to Beijing, respectively. Policy interventions were proposed accordingly.

The Beijing–Tianjin–Hebei (BTH) region has been suffering from the most severe fine-particle (PM2. 5) pollution in China, which causes serious health damage and economic loss. Quantifying the source contributions to PM2. 5 concentrations has been a challenging task because of the complicated nonlinear relationships between PM2. 5 concentrations and emissions of multiple pollutants from multiple spatial regions and economic sectors. In this study, we use the extended response surface modeling (ERSM) technique to investigate the nonlinear response of PM2. 5 concentrations to emissions of multiple pollutants from different regions and sectors over the BTH region, based on over 1000 simulations by a chemical transport model (CTM). The ERSM-predicted PM2. 5 concentrations agree well with independent CTM simulations, with correlation coefficients larger than 0.99 and mean normalized errors less than 1 %. Using the ERSM technique, we find that, among all air pollutants, primary inorganic PM2. 5 makes the largest contribution (24–36 %) to PM2. 5 concentrations. The contribution of primary inorganic PM2. 5 emissions is especially high in heavily polluted winter and is dominated by the industry as well as residential and commercial sectors, which should be prioritized in PM2. 5 control strategies. The total contributions of all precursors (nitrogen oxides, NOx; sulfur dioxides, SO2; ammonia, NH3; non-methane volatile organic compounds, NMVOCs; intermediate-volatility organic compounds, IVOCs; primary organic aerosol, POA) to PM2. 5 concentrations range between 31 and 48 %. Among these precursors, PM2. 5 concentrations are primarily sensitive to the emissions of NH3, NMVOC + IVOC, and POA. The sensitivities increase substantially for NH3 and NOx and decrease slightly for POA and NMVOC + IVOC with the increase in the emission reduction ratio, which illustrates the nonlinear relationships between precursor emissions and PM2. 5 concentrations. The contributions of primary inorganic PM2. 5 emissions to PM2. 5 concentrations are dominated by local emission sources, which account for over 75 % of the total primary inorganic PM2. 5 contributions. For precursors, however, emissions from other regions could play similar roles to local emission sources in the summer and over the northern part of BTH. The source contribution features for various types of heavy-pollution episodes are distinctly different from each other and from the monthly mean results, illustrating that control strategies should be differentiated based on the major contributing sources during different types of episodes.

Based on the data of Industrial Statistics Yearbooks of Beijing, Tianjin and Hebei from 2011 to 2015, this paper evaluated the synergy of innovation factors in equipment manufacturing industry by m...

The Beijing-Tianjin-Hebei (BTH) region experiences heavy aerosol pollution, which is found to have close relationships with the synoptic- and local-scale atmospheric circulations. However, how and to what extent these multi-scale circulations interplay to modulate aerosol transport have not been fully understood. To this end, this study comprehensively investigated the impacts of these circulations on aerosol transport in BTH by focusing on an episode occurred on 1 June 2013 through combining both observations and three-dimensional simulations. It was found that during this episode, the Bohai Sea acted as a transfer station, and the high-pressure system over the Yellow Sea and sea-breeze in BTH took turns to affect the transport of aerosols. In the morning, influenced by the high-pressure system, lots of aerosols emitted from Shandong and Jiangsu provinces were first transported to the Bohai Sea. After then, these aerosols were brought to the BTH region in the afternoon through the inland penetration of sea-breeze, significantly exacerbating the air quality in BTH. The inland penetration of sea-breeze could be identified by the sharp changes in ground-based observed temperature, humidity, and wind when the sea-breeze front (SBF) passed by. Combining observations with model outputs, the SBF was found to be able to advance inland more than ∼150 km till reaching Beijing. This study has important implications for better understanding the aerosol transport in BTH, and improving the forecast of such aerosol pollution.

The Beijing–Tianjin–Hebei (BTH) region is one of the most heavily polluted regions in China, with both high PM2.5 concentrations and a high population density. A quantitative source-receptor relationship can provide valuable insights that can inform effective emission control strategies. Both source apportionment (SA) and source sensitivity (SS) can provide such information from different perspectives. In this study, both methods are applied in northern China to identify the most significant emission categories and source regions for PM2.5 exposure in BTH in 2013. Despite their differences, both models show similar distribution patterns for population and simulated PM2.5 concentrations, resulting in overall high PM2.5 exposure values (approximately 110 μg/m3) and particularly high exposure values during the winter (approximately 200 μg/m3). Both methods show that local emissions play a dominant role (70%), with some contribution from surrounding provinces (e.g., Shandong) via regional transport. The two methods also agree on the priority of local emission controls: both identify industrial, residential, and agricultural emissions as the top three categories that should be controlled locally. In addition, the effect of controlling agricultural ammonia emissions is approximately doubled when the co-benefits of reducing nitrate are considered. The synthesis of SA and SS for addressing specific categories of emissions provides a quantitative basis for the development of emission control strategies and policies for controlling PM2.5 in China.

In 2013, China issued "Air Pollution Prevention and Control Action Plan (Action Plan)" to improve air quality. To assess the benefits of this program in Beijing-Tianjin-Hebei (BTH) region, where the density of population and emissions vary greatly, we simulated the air quality benefit based on BenMAP to satisfy the Action Plan. In this study, we estimate PM2.5 concentration using Voronoi spatial interpolation method on a grid with a spatial resolution of 1×1km2. Combined with the exposure-response function between PM2.5 concentration and health endpoints, health effects of PM2.5 exposure are analyzed. The economic loss is assessed by using the willingness to pay (WTP) method and human capital (HC) method. When the PM2.5 concentration falls by 25% in BTH and reached 60μg/m3 in Beijing, the avoiding deaths will be in the range of 3175 to 14051 based on different functions each year. Of the estimated mortality attributable to all causes, 3117 annual deaths were due to lung cancer, 1924 - 6318 annual deaths were due to cardiovascular, and 343 - 1697 annual deaths were due to respiratory. Based on WTP, the estimated monetary values for the avoided cases of all cause mortality, cardiovascular mortality, respiratory mortality and lung cancer ranged from 1110 to 29632, 673 to 13325, 120 to 3579, 1091 to 6574 million yuan, respectively. Based on HC, the corresponding values for the avoided cases of these four mortalities were 267 to 1178, 161 to 529, 29 to 143 and 261 million yuan, respectively.