The internal technological innovation(IT)and external technological cooperation(ET)of a city are crucial drivers for its green development(GD).Although previous studies have extensively explored the effect of IT on GD...The internal technological innovation(IT)and external technological cooperation(ET)of a city are crucial drivers for its green development(GD).Although previous studies have extensively explored the effect of IT on GD,IT,ET and GD have not been integrated into the same framework to explore their relationship.Using panel data of 13 cities in the Beijing-Tianjin-Hebei urban agglomeration,this study revealed the spatio-temporal evolution of GD and analyzed the effects of IT and ET on GD from the perspective of baseline impact,spatial effect and synergy effect.Empirical results demonstrate that the level of urban GD has upgraded and the difference in GD between cities has been narrowed though it decreases from the middle to both ends.IT significantly promotes the growth of GD while ET has an inverted U-shaped effect on GD.Under the influence of spatial spillover,IT has a U-shaped effect on the GD of neighboring cities while the effect of ET on neighboring GD is not significant.Additionally,the interaction between IT and ET has not been effective,leading to an insignificant synergy effect on GD.These findings will provide reference for taking rational advantage of IT and ET to facilitate urban GD.展开更多
Green development is a critical component of sustainable tourism, which prioritizes a comprehensive, ecologically-friendly, and people-oriented approach to development. This study presents a case study of the Beijing...Green development is a critical component of sustainable tourism, which prioritizes a comprehensive, ecologically-friendly, and people-oriented approach to development. This study presents a case study of the Beijing–Tianjin–Hebei(BTH) urban agglomeration from 2001 to 2021 to analyze the spatio-temporal evolution characteristics and influencing factors of tourism green development efficiency(TGDE). The study defines the concept of tourism green development and constructs an evaluation system, which is used to explore the internal differences and spatial patterns of TGDE within the urban agglomeration. The methodological approach includes the SBM–Undesirable model, kernel density estimation, Markov chain, and spatial gravity model. The findings indicate that the TGDE in the BTH urban agglomeration is generally favorable, displaying a temporal phase of “rising–declining–rising.” However, the study observes lower TGDE in tourism node cities compared to tourism regional center cities and tourism core hub cities. The non-equilibrium degree of each region indicates significant spatio-temporal evolution patterns and internal differences among the three regions, with a spatially decreasing distribution of “core hub-regional center-node city.” The TGDE in the urban agglomeration experienced an evolutionary trend of “first decreasing and then increasing” with apparent endogenous evolution characteristics. The linkage pattern of green development efficiency in the tourism industry between cities is relatively stable. Furthermore,neighboring cities generally exhibit a higher spatial connectivity strength of green development efficiency in the tourism industry compared to non-neighboring cities. Economic development level, industrial structure, and science and education level are identified as key factors that affect TGDE. However, the study finds that the factors influencing TGDE in tourism core hub cities, tourism regional center cities, and tourism node cities differ somewhat. Economic development level, industrial structure, science and education level, openness, and government regulation impact TGDE in tourism core hub cities and tourism regional center cities, while economic development level, industrial structure, and tourism resource endowment are the primary factors affecting TGDE in tourism node cities. The study provides policymakers and tourism practitioners with valuable insights into enhancing the green development of the tourism industry in the BTH urban agglomeration and other similar regions.Corresponding policy recommendations based on the results are proposed to improve the TGDE of the tourism industry in these regions, promote sustainable tourism development,improve the quality of life of local residents, and protect the ecological environment.展开更多
High-quality development is the primary task of comprehensively building a socialist,modern country,as well as the primary task of building urban agglomerations in China.Based on the five development concepts,this pap...High-quality development is the primary task of comprehensively building a socialist,modern country,as well as the primary task of building urban agglomerations in China.Based on the five development concepts,this paper used the entropy method to measure the High Quality Development Index(HQDI)of the five major urban agglomerations.The results showed that the HQDI of the five major urban agglomerations shows a fluctuating upward trend.First,using the Dagum Gini coefficient to explore the sources of HQDI development differences in urban agglomerations,we found that the main source of HQDI differences in urban agglomerations was inter-regional differences,while intra-regional differences were not important.Second,kernel density estimation was used to test the dynamic evolution trend of HQDI within urban agglomerations.There was a polarisation phenomenon in the HQDI of urban agglomerations,such as the Pearl River Delta urban agglomeration and the Chengdu-Chongqing urban agglomeration.But overall,the degree of imbalance had decreased.Third,using geographic detectors to examine the driving factors of HQDI in urban agglomerations,we found that the main driving forces for improving HQDI in urban agglomerations were economic growth,artificial intelligence technology and fiscal decentralisation.All the interaction factors had greater explanatory power for the spatial differentiation of HQDI,which can be divided into two types:two-factor improvement and non-linear improvement.This study is conducive to improving and enriching the theoretical system for evaluating the high quality development of urban agglomerations,and provides policy references for promoting the high quality development of urban agglomerations.展开更多
The inter-city linkage heat data provided by Baidu Migration is employed as a characterization of inter-city linkages in order to facilitate the study of the network linkage characteristics and hierarchical structure ...The inter-city linkage heat data provided by Baidu Migration is employed as a characterization of inter-city linkages in order to facilitate the study of the network linkage characteristics and hierarchical structure of urban agglomeration in the Greater Bay Area through the use of social network analysis method.This is the inaugural application of big data based on location services in the study of urban agglomeration network structure,which represents a novel research perspective on this topic.The study reveals that the density of network linkages in the Greater Bay Area urban agglomeration has reached 100%,indicating a mature network-like spatial structure.This structure has given rise to three distinct communities:Shenzhen-Dongguan-Huizhou,Guangzhou-Foshan-Zhaoqing,and Zhuhai-Zhongshan-Jiangmen.Additionally,cities within the Greater Bay Area urban agglomeration play different roles,suggesting that varying development strategies may be necessary to achieve staggered development.The study demonstrates that large datasets represented by LBS can offer novel insights and methodologies for the examination of urban agglomeration network structures,contingent on the appropriate mining and processing of the data.展开更多
Urban agglomerations,serving as pivotal centers of human activity,undergo swift alterations in ecosystem services prompted by shifts in land utilization.Strengthening the monitoring of ecosystem services in present an...Urban agglomerations,serving as pivotal centers of human activity,undergo swift alterations in ecosystem services prompted by shifts in land utilization.Strengthening the monitoring of ecosystem services in present and future urban agglomerations contributes to the rational planning of these areas and enhances the well-being of their inhabitants.Here,we analyzed land use conversion in the Yangtze River Delta(YRD)urban agglomeration during 1990-2020 and discussed the spatiotemporal response and main drivers of changes in ecosystem service value(ESV).By considering the different development strategic directions described in land use planning policies,we predicted land use conversion and its impact on ESV using the Future Land Use Simulation(FLUS)model in three scenari-os in 2025 and 2030.Results show that:1)from 1990 to 2020,land use change is mainly manifested as the continuous expansion of con-struction land to cultivated land.Among the reduced cultivated land,82.2%were occupied by construction land.2)The land use types conversion caused a loss of 21.85 billion yuan(RMB)in ESV during 1990-2020.Moreover,the large reduction of cultivated land area led to the continuous decline of food production value,accounting for 13%of the total ESV loss.3)From 2020 to 2030,land use change will mainly focus on Yangzhou and Zhenjiang in central Jiangsu Province and Taizhou in southern Zhejiang Province.Under the BAU(natural development)and ED(cultivated land protection)scenarios,construction land expansion remains dominant.In contrast,under the EP(ecological protection)scenario,the areas of water bodies and forest land increase significantly.Among the different scenarios,ESV is highest in the EP scenario,making it the optimal solution for sustainable land use.It can be seen that the space use conflict among urban,agriculture and ecology is a key factor leading to ESV change in the urban agglomeration of Yangtze River Delta.There-fore,it is crucial to maintain spatial land use coordination.Our findings provide suggestions for scientific and rational land use planning for the urban agglomeration.展开更多
Carbon storage of terrestrial ecosystems plays a vital role in advancing carbon neutrality. Better understanding of how land use changes affect carbon storage in urban agglomeration will provide valuable guidance for ...Carbon storage of terrestrial ecosystems plays a vital role in advancing carbon neutrality. Better understanding of how land use changes affect carbon storage in urban agglomeration will provide valuable guidance for policymakers in developing effective regional conservation policies. Taking the Pearl River Delta Urban Agglomeration(PRDUA) in China as an example, we examined the heterogeneous response of carbon storage to land use changes in 1990–2018 from a combined view of administrative units and physical entities. The results indicate that the primary change in land use was due to the expansion of construction land(5897.16 km2). The carbon storage in PRDUA decreased from 767.34 Tg C in 1990 to 725.42 Tg C in 2018 with a spatial pattern of high wings and the low middle. The carbon storage loss was largely attributed to construction land expansion(55.74%), followed by forest degradation(54.81%). Changes in carbon storage showed significant divergences in different sized cities and hierarchical boundaries. The coefficients of geographically weighted regression(GWR) reveal that the alteration in carbon storage in Guangzhou City was more responsive to changes in construction land(-0.11) compared to other cities, while that in Shenzhen was mainly affected by the dynamics of forest land(8.32). The change in carbon storage was primarily influenced by the conversion of farmland within urban extent(5.05) and the degradation of forest land in rural areas(5.82). Carbon storage changes were less sensitive to the expansion of construction land in the urban center, urban built-up area, and ex-urban built-up area, with the corresponding GWR coefficients of 0.19, 0.04, and 0.02. This study necessitates the differentiated protection strategies of carbon storage in urban agglomerations.展开更多
Since China announced its goal of becoming carbon-neutral by 2060, carbon neutrality has become a major target in the development of China's urban agglomerations. This study applied the Future Land Use Simulation(...Since China announced its goal of becoming carbon-neutral by 2060, carbon neutrality has become a major target in the development of China's urban agglomerations. This study applied the Future Land Use Simulation(FLUS) model to predict the land use pattern of the ecological space of the Beibu Gulf urban agglomeration, in 2060 under ecological priority, agricultural priority and urbanized priority scenarios. The Integrated Valuation of Ecosystem Services and Trade-offs(In VEST) model was employed to analyse the spatial changes in ecological space carbon storage in each scenario from 2020 to 2060. Then, this study used a Geographically Weighted Regression(GWR) model to determine the main driving factors that influence the changes in land carbon sinking capacity. The results of the study can be summarised as follows: firstly, the agricultural and ecological priority scenarios will achieve balanced urban expansion and environmental protection of resources in an ecological space. The urbanized priority scenario will reduce the carbon sinking capacity. Among the simulation scenarios for 2060, carbon storage in the urbanized priority scenario will decrease by 112.26 × 10^(6) t compared with that for 2020 and the average carbon density will decrease by 0.96 kg/m^(2) compared with that for 2020. Carbon storage in the agricultural priority scenario will increase by 84.11 × 10^(6) t, and the average carbon density will decrease by 0.72 kg/m^(2). Carbon storage in the ecological priority scenario will increase by 3.03 × 10^(6) t, and the average carbon density will increase by 0.03 kg/m^(2). Under the premise that the population of the town will increases continuously, the ecological priority development approach may be a wise choice.Secondly, slope, distance to river and elevation are the most important factors that influence the carbon sink pattern of the ecological space in the Beibu Gulf urban agglomeration, followed by GDP, population density, slope direction and distance to traffic infrastructure.At the same time, urban space expansion is the main cause of the changes of this natural factors. Thirdly, the decreasing trend of ecological space is difficult to reverse, so reasonable land use policy to curb the spatial expansion of cities need to be made.展开更多
Urban agglomeration(UA)is an advanced spatial economic form formed and developed in the process of rapid industrialization and urbanization,and an important carrier of urbanization and economic development.The economy...Urban agglomeration(UA)is an advanced spatial economic form formed and developed in the process of rapid industrialization and urbanization,and an important carrier of urbanization and economic development.The economy has developed rapidly in the recent decades of China,and the UAs have also developed rapidly.However,as a large population country,the population distribution and changes of UAs in China has unique characteristics.Using the fifth,sixth and seventh population census data,spatial auto-correlation and spatial econometric models,we analyzed the spatial-temporal evolution characteristics and influencing factors of population agglomeration in China’s UAs.Results revealed that:1)from 2000 to 2020,the population gradually converged into UAs,and the characteristics of population agglomeration in different development degree of UAs differ.The higher the development degree of UA,the higher the population agglomeration degree.Besides,UAs are the main area with the most significant population agglomeration degree,and the spatial autocorrelation show that the cities with similar degree tend to be concentrated in space.The urban population gathering in UAs has a certain positive spillover effect on population size of neighboring cities.2)Economic development and social conditions factors are important factors affecting population agglomeration degree in UAs.The main factors of population gather into UAs are similar with the outside UAs,but the positive promotion of urbanization rate and proportion of tertiary industry in GDP on population agglomeration of UAs in China are enhancing from 2000 to 2020.Meanwhile,the other factors,such as high-quality public services,good urban living environment conditions,high-quality medical and educational resources,are also important factors to promote urban population gather into UAs.This study provides a basis for formulating the development planning of UAs in China,and enriches the relevant theoretical research of population evolution and influencing factors of UAs.展开更多
This study constructs a quasi-natural experiment based on the expansion of the Yangtze River Delta urban agglomeration(YRDUA) of China in 2010 to investigate the impact and inner mechanism of urban agglomeration expan...This study constructs a quasi-natural experiment based on the expansion of the Yangtze River Delta urban agglomeration(YRDUA) of China in 2010 to investigate the impact and inner mechanism of urban agglomeration expansion on fine particulate matter(PM_(2.5)) concentrations through propensity scores in difference-in-differences models(PSM-DID) using panel data from 286 prefecturelevel cities in China from 2003 to 2016. The results show that 1) urban agglomeration expansion contributes to an overall decrease in PM_(2.5)concentration, which is mainly achieved from the original cities. For the new cities, on the other hand, the expansion significantly increases the local PM_(2.5)concentration. 2) In the long term, the significant influence of urban agglomeration expansion on PM_(2.5)concentration lasts for three years and gradually decreases. A series of robustness tests confirm the applicability of the PSM-DID model.3) Cities with weaker government regulation, a better educated population and higher per capita income present stronger PM_(2.5)reduction effects. 4) Urban agglomeration expansion affects the PM_(2.5)concentration mainly through industrial transfer and population migration, which cause a decrease in the PM_(2.5)concentration in the original cities and an increase in the PM_(2.5)concentration in the new cities.Corresponding policy suggestions are proposed based on the conclusions.展开更多
This paper examines national urban agglomerations by taking factor flows as the focal point as the research subject.By dividing the stages of urban agglomeration development,a comprehensive framework of urban shrinkag...This paper examines national urban agglomerations by taking factor flows as the focal point as the research subject.By dividing the stages of urban agglomeration development,a comprehensive framework of urban shrinkage is constructed,encompassing economic,population,and social shrinkage.The study explores the spatial distribution characteristics of urban shrinkage during different stages of urban agglomeration and investigates the influencing factors using a geographic detector model.The findings reveal that urban shrinkage within urban agglomerations is widely spread,predominantly in peripheral areas.During the diffusion stage,urban shrinkage is scattered,with population shrinkage concentrated in peripheral regions,economic shrinkage concentrated on old industrial cities,and social shrinkage concentrated on the northeast.The outcomes of the geographic detector model indicate that traffic flow,capital flow,information flow,node importance,network connectivity,government investment,openness,and environmental regulations all play significant roles in shaping the spatial distribution of urban shrinkage.展开更多
It is crucial to investigate the urban agglomerations spatio-temporal evolution patterns and driving factors for analyzing the urban spatial structure-functional division and promoting the coordinated development of u...It is crucial to investigate the urban agglomerations spatio-temporal evolution patterns and driving factors for analyzing the urban spatial structure-functional division and promoting the coordinated development of urban agglomerations.In this study,a novel vegetation-building-nighttime light-adjusted index(VBNAI)was established for rapid and effective mapping of urban construction land(UCL)in Central Plains Urban Agglomeration(CPUA),China during 2000–2020 based on Google Earth Engine(GEE)platform.Compared with traditional indices,VBNAI can significantly decrease the blooming effect,Normalized Difference Vegetation Index(NDVI)saturation,and soil background of nighttime light data.In addition,the urban expansion indices and standard deviation ellipse model were synthetically adopted to analyze the spatio-temporal evolution pattern of urban expansion.The gravity model and the geographically weighted regression model were employed to determine the spatial interaction forces and drivers of urban expansion,respectively.The results showed that the VBNAI index has obvious advantages in efficiency and accuracy to extract UCL with the overall accuracy of more than 91%.The UCL of CPUA had increased by 4489.84 km2 during 2000–2020 with the gravity center moving towards southeast continuously.From 2000 to 2010,the urban expansion was in a‘center-hinterland’pattern which had benefit from the favorable effect of the traffic shaft belt.During 2010–2020,the urban network structure had basically established.Urban expansion had been influenced by a variety of socio-economic and demographic factors,and the impact degree varied from region to region.This study could provide scientific references for facilitating the intensive utilization of urban resources and optimizing the spatial development pattern of urban agglomeration.展开更多
With the rapid development of urban agglomerations in northwest arid and semiarid regions of China, the scope of the urban heat island(UHI) effect has gradually expanded and gradually connected, and has formed a regio...With the rapid development of urban agglomerations in northwest arid and semiarid regions of China, the scope of the urban heat island(UHI) effect has gradually expanded and gradually connected, and has formed a regional heat island(RHI) with a larger range of impact to the regional environment. However, there are few studies on the heat island effect of urban agglomerations in arid and semiarid regions, so this paper selects the urban agglomeration of Hohhot, Baotou and Ordos(HBO) of Inner Mongolia, China as the study area. Based on the 8-day composite Moderate-resolution Imaging Spectroradiometer(MODIS) surface temperature data(156scenes in all) and land use maps for 2005, 2010, and 2015, we analyze the spatiotemporal distributions of regional heat(cool) islands(RH(C)I) and the responses of surface temperatures to land-use changes in the diurnal and interannual surface cities. The results showed that: 1) from 2005 to 2015, urban areas showed the cold island effect during the day, with the area of the cold island showing a shrinking feature;at night, they showed the heat island effect, with the area of the heat island showing a first decrease and then an increase.2) From 2005 to 2015, the land development(unutilized land to building land) brings the greatest temperature increase(ΔT = 1.36°C)during the day, while the greatest temperature change at night corresponds to the conversion of cultivated land to building land(ΔT =0.78°C) exhibited the largest changes at night. From 2010 to 2015, the land development(grassland to building land) bring the greatest temperature increase(ΔT = 0.85°C) during the day, while the great temperature change at night corresponds to the conversion of water areas to building land(ΔT = 1.38°C) exhibited the largest changes at night. Exploring the spatial and temporal evolution of surface urban heat(cool) islands in urban agglomerations in arid and semiarid regions will help to understand the urbanization characteristics of urban agglomerations and provide a reference for the formulation of policies for the coordinated and healthy development of the region and co-governance of regional environmental problems.展开更多
The Beijing-Tianjin-Hebei region is the vanguard of economic development in northern China.Its manufacturing industry is more and more developed,but environmental pollution is also more serious.Based on the data of 13...The Beijing-Tianjin-Hebei region is the vanguard of economic development in northern China.Its manufacturing industry is more and more developed,but environmental pollution is also more serious.Based on the data of 13 cities in Beijing-Tianjin-Hebei region from 2017 to 2021,the paper verifies the impact of manufacturing agglomeration on environmental pollution.Both manufacturing agglomeration and environmental pollution are dependent on spatial distribution.Therefore,the paper selects spatial econometric model to study.First,the spatial lag model and spatial error model are constructed,and then the spatial lag model is selected through the results of OLS regression,LM Test and Hausman test,and the empirical process is carried out.Finally,the empirical results are analyzed and the conclusion is drawn.展开更多
The overall NDVI characteristics and precipitation sensitivity in the study area from 2000 to 2018 were investigated using NDVI images of urban agglomeration in central Shanxi basin in 2000,2005,2010,and 2018 as well ...The overall NDVI characteristics and precipitation sensitivity in the study area from 2000 to 2018 were investigated using NDVI images of urban agglomeration in central Shanxi basin in 2000,2005,2010,and 2018 as well as the climate data of China’s surface cumulative annual value data set(1981-2010)in accordance with the method such as the geographically weighted regression model.As can be seen from the results,first,the overall NDVI pattern of urban agglomeration in central Shanxi basin,China has been changed and distributed along the topography in the shape of strip.Second,the spatial evolution of NDVI in the study area is varied significantly with the trend of expansion as a whole and a shrinking trend in some areas.Third,the overall precipitation in the study area presents a declining trend from the west to the east,while the NDVI precipitation sensitivity shows a decreasing trend from west to east.To be specific,the west and the east have a positive value of 1.3129 with strong sensitivity and a negative value of-1.0908 with weak sensitivity,respectively.The study results are expected to provide a scientific basis for restoring vegetation and formulating disaster prevention policies for urban agglomeration in Central Shanxi Basin.展开更多
We use emergy-based urban metabolism analysis in this study to investigate the local coupling and telecoupling between urbanization and the eco-environment in the Beijing-Tianjin-Hebei urban agglomeration. Our analysi...We use emergy-based urban metabolism analysis in this study to investigate the local coupling and telecoupling between urbanization and the eco-environment in the Beijing-Tianjin-Hebei urban agglomeration. Our analysis encompasses the last 35 years spanning the period between 1980 and 2014. In addition, we analyze urban metabolic efficiency and environmental pressure in these couplings. There are three main conclusions of this study. First, we show that the total metabolic emergy value of the Beijing-Tianjin-Hebei urban agglomeration has increased over the last 35 years, and that external elements have replaced internal ones as the leading contributors to urban metabolism in this region. The proportion of metabolic emergy derived from external elements increased from 30.87% in 1980 to 67.43% in 2014. The emergy extroversion ratio has continued to increase over our study period, while the development of this urban agglomeration had become progressively and more heavily reliant on external elements. Second, over the study period, the metabolic emergy intensity of elements of local coupling and telecoupling in the Beijing-Tianjin-Hebei urban agglomeration has declined at an accelerating rate, from 1.15×10^(21) Sej/100 million RMB in1980 to 9.69×10^(19) Sej/100 million RMB in 2014. This reflects a continuous increase in the economic efficiency of this area.Correspondingly, emergy use per capita increased from 7.8×10^(15) Sej/person in 1980 to 5.83×10^(16) Sej/person in 2014, suggesting a gradual rise in the level of social welfare in this urban agglomeration. However, we also observed a consistently elevated environmental loading ratio(ELR) in our analysis in terms of metabolism of local coupling and telecoupling elements. This result indicates that environmental pressure has also increased constantly within the Beijing-Tianjin-Hebei urban agglomeration. Third,our analysis shows that the ELR of metabolic emergy from internal elements increased from 8.30 in 1980 to 43.46 in 2014, while the ratio from external elements increased from 4.15 to 92.03. Thus, we quantitatively investigated the dependency of development within this urban agglomeration on external elements as well as the resultant environmental load. The conclusions of this study provide the basis for quantitative policy-making in the Beijing-Tianjin-Hebei region, optimizing economic structures, improving economic efficiency, controlling environmental pollution, and promoting the coordinated development of this region.展开更多
The Atmospheric Environmental Monitoring Network successfully undertook the task of monitoring the atmospheric quality of Beijing and its surrounding area during the 2008 Olympics. The results of this monitoring show ...The Atmospheric Environmental Monitoring Network successfully undertook the task of monitoring the atmospheric quality of Beijing and its surrounding area during the 2008 Olympics. The results of this monitoring show that high concentrations of PM2.5 pollution exhibited a regional pattern during the monitoring period （1 June-30 October 2008）. The PM2.5 mass concentrations were 53 μg m-3, 66 p.g m-3, and 82 μg m-3 at the background site, in Beijing, and in the Beijing-Tianjin-Hebei urban agglomerations, respectively. The PM2.5 levels were lowest during the 2008 Olympic Games （8-24 August）： 35μg m-3 at the background site, 42 μg m-3 in Beijing and 57 μg m-3 in the region. These levels represent decreases of 49%, 48% and 56%, respectively, compared to the prophase mean concentration before the Olympic Games. Emission control measures contributed 62% 82% of the declines observed in Beijing, and meteorological conditions represented 18%-38%. The concentration of fine particles met the goals set for a ＂Green Olympics.＂展开更多
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 evalu...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-TianjinHebei 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.There is positive correlation with overall weak space between cities, and the partial spatial agglomeration phenomenon appears. Therefore, the green land use efficiency could be improved by improving land utilization efficiency, coordinating economic growth of construction land utilization with environmental protection and taking feasible ways to transregional renovation of the stock ecological land utilization, etc.展开更多
This paper adopts the perspective of urban economic linkage and the modified urban economic gravity model to conduct a comparative analysis of the economic gravity among cities in China’s three major urban agglomerat...This paper adopts the perspective of urban economic linkage and the modified urban economic gravity model to conduct a comparative analysis of the economic gravity among cities in China’s three major urban agglomerations,including the Beijing-Tianjin-Hebei region,the Yangtze River Delta,and the Pearl River Delta.The results show that,despite the ever-tightening economic linkages among cities in the urban agglomerations,the development of the Beijing-Tianjin-Hebei region falls behind that of the Yangtze River Delta and the Pearl River Delta in terms of coordination,closeness,and balance.The economic linkages among cities in the Beijing-Tianjin-Hebei region are not as cohesive as they could be and display a significant“siphon effect”through Beijing and Tianjin as well as a prominently unidirectional economic flow.This study suggests that efforts should be put into directing the orderly flow of resources from Beijing and Tianjin to cities in Hebei and promoting a balanced economic flow among cities,thus facilitating the coordination of regional development.展开更多
Spatial structure of rural tourism in the urban agglomerations of Wuhan was analyzed by comprehensively studying relevant documents about rural tourism,and reviewing previous researches on the concept and spatial stru...Spatial structure of rural tourism in the urban agglomerations of Wuhan was analyzed by comprehensively studying relevant documents about rural tourism,and reviewing previous researches on the concept and spatial structure of rural tourism.Through investigating rural tourist resources in the study area,resource advantages and characteristics of 9 cities were introduced,and the Gini Coefficient was taken to quantitatively analyze spatial patterns of its rural tourist villages,the obviously imbalanced concentration of these villages was pointed out.By measuring connectivity and accessibility of regional spaces in the study area,its traffic connectivity was proved moderate,and accessibility of each tourist village and town was fine.Then an optimized spatial structure was proposed for the rural tourism development in Wuhan Urban Agglomerations,that is,"one core,one belt and three districts".展开更多
Characteristics of air pollution in Northeast China(NEC) received less research attention in the past comparing to other heavily polluted regions in China.Spatiotemporal variations of six criteria air pollutants(PM10,...Characteristics of air pollution in Northeast China(NEC) received less research attention in the past comparing to other heavily polluted regions in China.Spatiotemporal variations of six criteria air pollutants(PM10, PM2.5, SO2, NO2, O3 and CO) in Central Liaoning Urban Agglomeration(CLUA) and Harbin-Changchun Urban Agglomeration(HCUA) in NEC Plain were analyzed in this study based on three-year hourly observations of air pollutants and meteorological variables from 2015 to 2017.The results indicated that the annual mean concentrations of air pollutants are generally higher in the middle and southern regions in NEC Plain and lower in the northern region.Megacities such as Shenyang, Harbin and Changchun experience severe air pollution, with a three-year averaged air quality index(AQI) larger than 80, far exceeding the daily AQI standard at the first-level of 50 in China.The annual mean PM and SO2 concentrations decrease most significantly in NEC urban agglomerations from 2015 to 2017, followed by CO and NO2, while O3 shows a slight increasing trend.All the six pollutants exhibit obvious seasonal and diurnal variations, and these variations are dictated by local emission and meteorological conditions.PM2.5 and O3 concentrations in NEC urban agglomerations strongly depend on wind conditions.High O3 concentrations at different cities usually occur in presence of strong winds but are independent on wind direction(WD), while high PM2.5 is usually accompanied by weak winds and poor dispersion condition, and sometimes also occur when the northerly or southerly winds are strong.Regional transport of air pollutants between NEC urban agglomerations is common.A severe haze event on November 1–4, 2017 is examined to demonstrate the role of regional transport on pollution.展开更多
基金National Natural Science Foundation of China,No.42371213Third Xinjiang Scientific Expedition Program,No.2021xjkk0900。
文摘The internal technological innovation(IT)and external technological cooperation(ET)of a city are crucial drivers for its green development(GD).Although previous studies have extensively explored the effect of IT on GD,IT,ET and GD have not been integrated into the same framework to explore their relationship.Using panel data of 13 cities in the Beijing-Tianjin-Hebei urban agglomeration,this study revealed the spatio-temporal evolution of GD and analyzed the effects of IT and ET on GD from the perspective of baseline impact,spatial effect and synergy effect.Empirical results demonstrate that the level of urban GD has upgraded and the difference in GD between cities has been narrowed though it decreases from the middle to both ends.IT significantly promotes the growth of GD while ET has an inverted U-shaped effect on GD.Under the influence of spatial spillover,IT has a U-shaped effect on the GD of neighboring cities while the effect of ET on neighboring GD is not significant.Additionally,the interaction between IT and ET has not been effective,leading to an insignificant synergy effect on GD.These findings will provide reference for taking rational advantage of IT and ET to facilitate urban GD.
基金National Natural Science Foundation of China,No.41771131China Scholarship Council,No.202008110050Key Program for Scientific Research of Beijing Union University,No.SKZD202306。
文摘Green development is a critical component of sustainable tourism, which prioritizes a comprehensive, ecologically-friendly, and people-oriented approach to development. This study presents a case study of the Beijing–Tianjin–Hebei(BTH) urban agglomeration from 2001 to 2021 to analyze the spatio-temporal evolution characteristics and influencing factors of tourism green development efficiency(TGDE). The study defines the concept of tourism green development and constructs an evaluation system, which is used to explore the internal differences and spatial patterns of TGDE within the urban agglomeration. The methodological approach includes the SBM–Undesirable model, kernel density estimation, Markov chain, and spatial gravity model. The findings indicate that the TGDE in the BTH urban agglomeration is generally favorable, displaying a temporal phase of “rising–declining–rising.” However, the study observes lower TGDE in tourism node cities compared to tourism regional center cities and tourism core hub cities. The non-equilibrium degree of each region indicates significant spatio-temporal evolution patterns and internal differences among the three regions, with a spatially decreasing distribution of “core hub-regional center-node city.” The TGDE in the urban agglomeration experienced an evolutionary trend of “first decreasing and then increasing” with apparent endogenous evolution characteristics. The linkage pattern of green development efficiency in the tourism industry between cities is relatively stable. Furthermore,neighboring cities generally exhibit a higher spatial connectivity strength of green development efficiency in the tourism industry compared to non-neighboring cities. Economic development level, industrial structure, and science and education level are identified as key factors that affect TGDE. However, the study finds that the factors influencing TGDE in tourism core hub cities, tourism regional center cities, and tourism node cities differ somewhat. Economic development level, industrial structure, science and education level, openness, and government regulation impact TGDE in tourism core hub cities and tourism regional center cities, while economic development level, industrial structure, and tourism resource endowment are the primary factors affecting TGDE in tourism node cities. The study provides policymakers and tourism practitioners with valuable insights into enhancing the green development of the tourism industry in the BTH urban agglomeration and other similar regions.Corresponding policy recommendations based on the results are proposed to improve the TGDE of the tourism industry in these regions, promote sustainable tourism development,improve the quality of life of local residents, and protect the ecological environment.
基金Under the auspices of National Natural Science Foundation of China(No.72373094,72303149)Scientific Research Start-up Funds of Guangdong Ocean University(No.060302082319)。
文摘High-quality development is the primary task of comprehensively building a socialist,modern country,as well as the primary task of building urban agglomerations in China.Based on the five development concepts,this paper used the entropy method to measure the High Quality Development Index(HQDI)of the five major urban agglomerations.The results showed that the HQDI of the five major urban agglomerations shows a fluctuating upward trend.First,using the Dagum Gini coefficient to explore the sources of HQDI development differences in urban agglomerations,we found that the main source of HQDI differences in urban agglomerations was inter-regional differences,while intra-regional differences were not important.Second,kernel density estimation was used to test the dynamic evolution trend of HQDI within urban agglomerations.There was a polarisation phenomenon in the HQDI of urban agglomerations,such as the Pearl River Delta urban agglomeration and the Chengdu-Chongqing urban agglomeration.But overall,the degree of imbalance had decreased.Third,using geographic detectors to examine the driving factors of HQDI in urban agglomerations,we found that the main driving forces for improving HQDI in urban agglomerations were economic growth,artificial intelligence technology and fiscal decentralisation.All the interaction factors had greater explanatory power for the spatial differentiation of HQDI,which can be divided into two types:two-factor improvement and non-linear improvement.This study is conducive to improving and enriching the theoretical system for evaluating the high quality development of urban agglomerations,and provides policy references for promoting the high quality development of urban agglomerations.
文摘The inter-city linkage heat data provided by Baidu Migration is employed as a characterization of inter-city linkages in order to facilitate the study of the network linkage characteristics and hierarchical structure of urban agglomeration in the Greater Bay Area through the use of social network analysis method.This is the inaugural application of big data based on location services in the study of urban agglomeration network structure,which represents a novel research perspective on this topic.The study reveals that the density of network linkages in the Greater Bay Area urban agglomeration has reached 100%,indicating a mature network-like spatial structure.This structure has given rise to three distinct communities:Shenzhen-Dongguan-Huizhou,Guangzhou-Foshan-Zhaoqing,and Zhuhai-Zhongshan-Jiangmen.Additionally,cities within the Greater Bay Area urban agglomeration play different roles,suggesting that varying development strategies may be necessary to achieve staggered development.The study demonstrates that large datasets represented by LBS can offer novel insights and methodologies for the examination of urban agglomeration network structures,contingent on the appropriate mining and processing of the data.
基金Under the auspices of National Natural Science Foundation of China(No.42276234)National Social Science Foundation Major Project of China(No.23&ZD105)+1 种基金the Open Fund of the Key Laboratory of Coastal Zone Exploitation and Protection,Ministry of Natural Resources of China(No.2023CZEPK04)the Science and Technology Major Project of Ningbo(No.2021Z181)。
文摘Urban agglomerations,serving as pivotal centers of human activity,undergo swift alterations in ecosystem services prompted by shifts in land utilization.Strengthening the monitoring of ecosystem services in present and future urban agglomerations contributes to the rational planning of these areas and enhances the well-being of their inhabitants.Here,we analyzed land use conversion in the Yangtze River Delta(YRD)urban agglomeration during 1990-2020 and discussed the spatiotemporal response and main drivers of changes in ecosystem service value(ESV).By considering the different development strategic directions described in land use planning policies,we predicted land use conversion and its impact on ESV using the Future Land Use Simulation(FLUS)model in three scenari-os in 2025 and 2030.Results show that:1)from 1990 to 2020,land use change is mainly manifested as the continuous expansion of con-struction land to cultivated land.Among the reduced cultivated land,82.2%were occupied by construction land.2)The land use types conversion caused a loss of 21.85 billion yuan(RMB)in ESV during 1990-2020.Moreover,the large reduction of cultivated land area led to the continuous decline of food production value,accounting for 13%of the total ESV loss.3)From 2020 to 2030,land use change will mainly focus on Yangzhou and Zhenjiang in central Jiangsu Province and Taizhou in southern Zhejiang Province.Under the BAU(natural development)and ED(cultivated land protection)scenarios,construction land expansion remains dominant.In contrast,under the EP(ecological protection)scenario,the areas of water bodies and forest land increase significantly.Among the different scenarios,ESV is highest in the EP scenario,making it the optimal solution for sustainable land use.It can be seen that the space use conflict among urban,agriculture and ecology is a key factor leading to ESV change in the urban agglomeration of Yangtze River Delta.There-fore,it is crucial to maintain spatial land use coordination.Our findings provide suggestions for scientific and rational land use planning for the urban agglomeration.
基金Under the auspices of National Natural Science Foundation of China (No.42171414,41771429)the Open Fund of Guangdong Enterprise Key Laboratory for Urban SensingMonitoring and Early Warning (No.2020B121202019)。
文摘Carbon storage of terrestrial ecosystems plays a vital role in advancing carbon neutrality. Better understanding of how land use changes affect carbon storage in urban agglomeration will provide valuable guidance for policymakers in developing effective regional conservation policies. Taking the Pearl River Delta Urban Agglomeration(PRDUA) in China as an example, we examined the heterogeneous response of carbon storage to land use changes in 1990–2018 from a combined view of administrative units and physical entities. The results indicate that the primary change in land use was due to the expansion of construction land(5897.16 km2). The carbon storage in PRDUA decreased from 767.34 Tg C in 1990 to 725.42 Tg C in 2018 with a spatial pattern of high wings and the low middle. The carbon storage loss was largely attributed to construction land expansion(55.74%), followed by forest degradation(54.81%). Changes in carbon storage showed significant divergences in different sized cities and hierarchical boundaries. The coefficients of geographically weighted regression(GWR) reveal that the alteration in carbon storage in Guangzhou City was more responsive to changes in construction land(-0.11) compared to other cities, while that in Shenzhen was mainly affected by the dynamics of forest land(8.32). The change in carbon storage was primarily influenced by the conversion of farmland within urban extent(5.05) and the degradation of forest land in rural areas(5.82). Carbon storage changes were less sensitive to the expansion of construction land in the urban center, urban built-up area, and ex-urban built-up area, with the corresponding GWR coefficients of 0.19, 0.04, and 0.02. This study necessitates the differentiated protection strategies of carbon storage in urban agglomerations.
基金Under the auspices of National Natural Science Foundation of China (No. 52268008, 51768001)。
文摘Since China announced its goal of becoming carbon-neutral by 2060, carbon neutrality has become a major target in the development of China's urban agglomerations. This study applied the Future Land Use Simulation(FLUS) model to predict the land use pattern of the ecological space of the Beibu Gulf urban agglomeration, in 2060 under ecological priority, agricultural priority and urbanized priority scenarios. The Integrated Valuation of Ecosystem Services and Trade-offs(In VEST) model was employed to analyse the spatial changes in ecological space carbon storage in each scenario from 2020 to 2060. Then, this study used a Geographically Weighted Regression(GWR) model to determine the main driving factors that influence the changes in land carbon sinking capacity. The results of the study can be summarised as follows: firstly, the agricultural and ecological priority scenarios will achieve balanced urban expansion and environmental protection of resources in an ecological space. The urbanized priority scenario will reduce the carbon sinking capacity. Among the simulation scenarios for 2060, carbon storage in the urbanized priority scenario will decrease by 112.26 × 10^(6) t compared with that for 2020 and the average carbon density will decrease by 0.96 kg/m^(2) compared with that for 2020. Carbon storage in the agricultural priority scenario will increase by 84.11 × 10^(6) t, and the average carbon density will decrease by 0.72 kg/m^(2). Carbon storage in the ecological priority scenario will increase by 3.03 × 10^(6) t, and the average carbon density will increase by 0.03 kg/m^(2). Under the premise that the population of the town will increases continuously, the ecological priority development approach may be a wise choice.Secondly, slope, distance to river and elevation are the most important factors that influence the carbon sink pattern of the ecological space in the Beibu Gulf urban agglomeration, followed by GDP, population density, slope direction and distance to traffic infrastructure.At the same time, urban space expansion is the main cause of the changes of this natural factors. Thirdly, the decreasing trend of ecological space is difficult to reverse, so reasonable land use policy to curb the spatial expansion of cities need to be made.
基金Under the auspices of National Planning Office of Philosophy and Social Science(No.17BRK010)。
文摘Urban agglomeration(UA)is an advanced spatial economic form formed and developed in the process of rapid industrialization and urbanization,and an important carrier of urbanization and economic development.The economy has developed rapidly in the recent decades of China,and the UAs have also developed rapidly.However,as a large population country,the population distribution and changes of UAs in China has unique characteristics.Using the fifth,sixth and seventh population census data,spatial auto-correlation and spatial econometric models,we analyzed the spatial-temporal evolution characteristics and influencing factors of population agglomeration in China’s UAs.Results revealed that:1)from 2000 to 2020,the population gradually converged into UAs,and the characteristics of population agglomeration in different development degree of UAs differ.The higher the development degree of UA,the higher the population agglomeration degree.Besides,UAs are the main area with the most significant population agglomeration degree,and the spatial autocorrelation show that the cities with similar degree tend to be concentrated in space.The urban population gathering in UAs has a certain positive spillover effect on population size of neighboring cities.2)Economic development and social conditions factors are important factors affecting population agglomeration degree in UAs.The main factors of population gather into UAs are similar with the outside UAs,but the positive promotion of urbanization rate and proportion of tertiary industry in GDP on population agglomeration of UAs in China are enhancing from 2000 to 2020.Meanwhile,the other factors,such as high-quality public services,good urban living environment conditions,high-quality medical and educational resources,are also important factors to promote urban population gather into UAs.This study provides a basis for formulating the development planning of UAs in China,and enriches the relevant theoretical research of population evolution and influencing factors of UAs.
基金Under the auspices of Chinese National Funding of Social Sciences (No.17AGL005)Institute of Socialism with Chinese Characteristics of Southeast University (No.DDZTZK2021C11)。
文摘This study constructs a quasi-natural experiment based on the expansion of the Yangtze River Delta urban agglomeration(YRDUA) of China in 2010 to investigate the impact and inner mechanism of urban agglomeration expansion on fine particulate matter(PM_(2.5)) concentrations through propensity scores in difference-in-differences models(PSM-DID) using panel data from 286 prefecturelevel cities in China from 2003 to 2016. The results show that 1) urban agglomeration expansion contributes to an overall decrease in PM_(2.5)concentration, which is mainly achieved from the original cities. For the new cities, on the other hand, the expansion significantly increases the local PM_(2.5)concentration. 2) In the long term, the significant influence of urban agglomeration expansion on PM_(2.5)concentration lasts for three years and gradually decreases. A series of robustness tests confirm the applicability of the PSM-DID model.3) Cities with weaker government regulation, a better educated population and higher per capita income present stronger PM_(2.5)reduction effects. 4) Urban agglomeration expansion affects the PM_(2.5)concentration mainly through industrial transfer and population migration, which cause a decrease in the PM_(2.5)concentration in the original cities and an increase in the PM_(2.5)concentration in the new cities.Corresponding policy suggestions are proposed based on the conclusions.
基金National Social Science Fund Project(22BZ039)Henan Province Science and Technology Tackling Key Problems Soft Science Project(222400410186)。
文摘This paper examines national urban agglomerations by taking factor flows as the focal point as the research subject.By dividing the stages of urban agglomeration development,a comprehensive framework of urban shrinkage is constructed,encompassing economic,population,and social shrinkage.The study explores the spatial distribution characteristics of urban shrinkage during different stages of urban agglomeration and investigates the influencing factors using a geographic detector model.The findings reveal that urban shrinkage within urban agglomerations is widely spread,predominantly in peripheral areas.During the diffusion stage,urban shrinkage is scattered,with population shrinkage concentrated in peripheral regions,economic shrinkage concentrated on old industrial cities,and social shrinkage concentrated on the northeast.The outcomes of the geographic detector model indicate that traffic flow,capital flow,information flow,node importance,network connectivity,government investment,openness,and environmental regulations all play significant roles in shaping the spatial distribution of urban shrinkage.
基金Under the auspices of Social Science and Humanity on Young Fund of the Ministry of Education of China(No.21YJCZH100)the Scientific Research Project on Outstanding Young of the Fujian Agriculture and Forestry University(No.XJQ201920)+1 种基金the Science and Technology Innovation Special Fund Project of Fujian Agriculture and Forestry University(No.CXZX2021032)the Forestry Peak Discipline Construction Project of Fujian Agriculture and Forestry University(No.72202200205)。
文摘It is crucial to investigate the urban agglomerations spatio-temporal evolution patterns and driving factors for analyzing the urban spatial structure-functional division and promoting the coordinated development of urban agglomerations.In this study,a novel vegetation-building-nighttime light-adjusted index(VBNAI)was established for rapid and effective mapping of urban construction land(UCL)in Central Plains Urban Agglomeration(CPUA),China during 2000–2020 based on Google Earth Engine(GEE)platform.Compared with traditional indices,VBNAI can significantly decrease the blooming effect,Normalized Difference Vegetation Index(NDVI)saturation,and soil background of nighttime light data.In addition,the urban expansion indices and standard deviation ellipse model were synthetically adopted to analyze the spatio-temporal evolution pattern of urban expansion.The gravity model and the geographically weighted regression model were employed to determine the spatial interaction forces and drivers of urban expansion,respectively.The results showed that the VBNAI index has obvious advantages in efficiency and accuracy to extract UCL with the overall accuracy of more than 91%.The UCL of CPUA had increased by 4489.84 km2 during 2000–2020 with the gravity center moving towards southeast continuously.From 2000 to 2010,the urban expansion was in a‘center-hinterland’pattern which had benefit from the favorable effect of the traffic shaft belt.During 2010–2020,the urban network structure had basically established.Urban expansion had been influenced by a variety of socio-economic and demographic factors,and the impact degree varied from region to region.This study could provide scientific references for facilitating the intensive utilization of urban resources and optimizing the spatial development pattern of urban agglomeration.
文摘With the rapid development of urban agglomerations in northwest arid and semiarid regions of China, the scope of the urban heat island(UHI) effect has gradually expanded and gradually connected, and has formed a regional heat island(RHI) with a larger range of impact to the regional environment. However, there are few studies on the heat island effect of urban agglomerations in arid and semiarid regions, so this paper selects the urban agglomeration of Hohhot, Baotou and Ordos(HBO) of Inner Mongolia, China as the study area. Based on the 8-day composite Moderate-resolution Imaging Spectroradiometer(MODIS) surface temperature data(156scenes in all) and land use maps for 2005, 2010, and 2015, we analyze the spatiotemporal distributions of regional heat(cool) islands(RH(C)I) and the responses of surface temperatures to land-use changes in the diurnal and interannual surface cities. The results showed that: 1) from 2005 to 2015, urban areas showed the cold island effect during the day, with the area of the cold island showing a shrinking feature;at night, they showed the heat island effect, with the area of the heat island showing a first decrease and then an increase.2) From 2005 to 2015, the land development(unutilized land to building land) brings the greatest temperature increase(ΔT = 1.36°C)during the day, while the greatest temperature change at night corresponds to the conversion of cultivated land to building land(ΔT =0.78°C) exhibited the largest changes at night. From 2010 to 2015, the land development(grassland to building land) bring the greatest temperature increase(ΔT = 0.85°C) during the day, while the great temperature change at night corresponds to the conversion of water areas to building land(ΔT = 1.38°C) exhibited the largest changes at night. Exploring the spatial and temporal evolution of surface urban heat(cool) islands in urban agglomerations in arid and semiarid regions will help to understand the urbanization characteristics of urban agglomerations and provide a reference for the formulation of policies for the coordinated and healthy development of the region and co-governance of regional environmental problems.
文摘The Beijing-Tianjin-Hebei region is the vanguard of economic development in northern China.Its manufacturing industry is more and more developed,but environmental pollution is also more serious.Based on the data of 13 cities in Beijing-Tianjin-Hebei region from 2017 to 2021,the paper verifies the impact of manufacturing agglomeration on environmental pollution.Both manufacturing agglomeration and environmental pollution are dependent on spatial distribution.Therefore,the paper selects spatial econometric model to study.First,the spatial lag model and spatial error model are constructed,and then the spatial lag model is selected through the results of OLS regression,LM Test and Hausman test,and the empirical process is carried out.Finally,the empirical results are analyzed and the conclusion is drawn.
基金supported by the National Natural Science Foundation of China(Grant No.41701223)。
文摘The overall NDVI characteristics and precipitation sensitivity in the study area from 2000 to 2018 were investigated using NDVI images of urban agglomeration in central Shanxi basin in 2000,2005,2010,and 2018 as well as the climate data of China’s surface cumulative annual value data set(1981-2010)in accordance with the method such as the geographically weighted regression model.As can be seen from the results,first,the overall NDVI pattern of urban agglomeration in central Shanxi basin,China has been changed and distributed along the topography in the shape of strip.Second,the spatial evolution of NDVI in the study area is varied significantly with the trend of expansion as a whole and a shrinking trend in some areas.Third,the overall precipitation in the study area presents a declining trend from the west to the east,while the NDVI precipitation sensitivity shows a decreasing trend from west to east.To be specific,the west and the east have a positive value of 1.3129 with strong sensitivity and a negative value of-1.0908 with weak sensitivity,respectively.The study results are expected to provide a scientific basis for restoring vegetation and formulating disaster prevention policies for urban agglomeration in Central Shanxi Basin.
基金supported by the Major Program of National Natural Science Foundation of China: “Coupled mechanism and interactive coercing effects between urbanization and eco-environment in mega-urban agglomerations” (Grant Nos. 41590840 & 41590842)
文摘We use emergy-based urban metabolism analysis in this study to investigate the local coupling and telecoupling between urbanization and the eco-environment in the Beijing-Tianjin-Hebei urban agglomeration. Our analysis encompasses the last 35 years spanning the period between 1980 and 2014. In addition, we analyze urban metabolic efficiency and environmental pressure in these couplings. There are three main conclusions of this study. First, we show that the total metabolic emergy value of the Beijing-Tianjin-Hebei urban agglomeration has increased over the last 35 years, and that external elements have replaced internal ones as the leading contributors to urban metabolism in this region. The proportion of metabolic emergy derived from external elements increased from 30.87% in 1980 to 67.43% in 2014. The emergy extroversion ratio has continued to increase over our study period, while the development of this urban agglomeration had become progressively and more heavily reliant on external elements. Second, over the study period, the metabolic emergy intensity of elements of local coupling and telecoupling in the Beijing-Tianjin-Hebei urban agglomeration has declined at an accelerating rate, from 1.15×10^(21) Sej/100 million RMB in1980 to 9.69×10^(19) Sej/100 million RMB in 2014. This reflects a continuous increase in the economic efficiency of this area.Correspondingly, emergy use per capita increased from 7.8×10^(15) Sej/person in 1980 to 5.83×10^(16) Sej/person in 2014, suggesting a gradual rise in the level of social welfare in this urban agglomeration. However, we also observed a consistently elevated environmental loading ratio(ELR) in our analysis in terms of metabolism of local coupling and telecoupling elements. This result indicates that environmental pressure has also increased constantly within the Beijing-Tianjin-Hebei urban agglomeration. Third,our analysis shows that the ELR of metabolic emergy from internal elements increased from 8.30 in 1980 to 43.46 in 2014, while the ratio from external elements increased from 4.15 to 92.03. Thus, we quantitatively investigated the dependency of development within this urban agglomeration on external elements as well as the resultant environmental load. The conclusions of this study provide the basis for quantitative policy-making in the Beijing-Tianjin-Hebei region, optimizing economic structures, improving economic efficiency, controlling environmental pollution, and promoting the coordinated development of this region.
基金supported by the Beijing Municipal Science & Technology Commission (Grant No.D09040903670902)the National Natural Science Foundation of China Grant Nos.41222033 and 41230642supported by the CAS Strategic Priority Research Program Grant No.XDA05100100
文摘The Atmospheric Environmental Monitoring Network successfully undertook the task of monitoring the atmospheric quality of Beijing and its surrounding area during the 2008 Olympics. The results of this monitoring show that high concentrations of PM2.5 pollution exhibited a regional pattern during the monitoring period （1 June-30 October 2008）. The PM2.5 mass concentrations were 53 μg m-3, 66 p.g m-3, and 82 μg m-3 at the background site, in Beijing, and in the Beijing-Tianjin-Hebei urban agglomerations, respectively. The PM2.5 levels were lowest during the 2008 Olympic Games （8-24 August）： 35μg m-3 at the background site, 42 μg m-3 in Beijing and 57 μg m-3 in the region. These levels represent decreases of 49%, 48% and 56%, respectively, compared to the prophase mean concentration before the Olympic Games. Emission control measures contributed 62% 82% of the declines observed in Beijing, and meteorological conditions represented 18%-38%. The concentration of fine particles met the goals set for a ＂Green Olympics.＂
基金supported by National Social Science Foundation of China"Research on the Spatial Optimization Mechanism and Path of the National Urban New District from the Perspective of Urban Agglomeration Integration"[Grant number:16BGL208],the principal of the project:Xia ZhouNational Natural Science Foundation of China"Coupling Mechanism between Land Price Gradient and Industrial Gradient and Optimization of Industrial Structure of Urban Agglomeration"[Grant number:71173148]Beijing Science and Technology Support"Green Channel"Project"Land Security for Non-capital Core Functions"[Grant number:2161100001116016],the principal of the project:Deqi Wang
文摘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-TianjinHebei 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.There is positive correlation with overall weak space between cities, and the partial spatial agglomeration phenomenon appears. Therefore, the green land use efficiency could be improved by improving land utilization efficiency, coordinating economic growth of construction land utilization with environmental protection and taking feasible ways to transregional renovation of the stock ecological land utilization, etc.
文摘This paper adopts the perspective of urban economic linkage and the modified urban economic gravity model to conduct a comparative analysis of the economic gravity among cities in China’s three major urban agglomerations,including the Beijing-Tianjin-Hebei region,the Yangtze River Delta,and the Pearl River Delta.The results show that,despite the ever-tightening economic linkages among cities in the urban agglomerations,the development of the Beijing-Tianjin-Hebei region falls behind that of the Yangtze River Delta and the Pearl River Delta in terms of coordination,closeness,and balance.The economic linkages among cities in the Beijing-Tianjin-Hebei region are not as cohesive as they could be and display a significant“siphon effect”through Beijing and Tianjin as well as a prominently unidirectional economic flow.This study suggests that efforts should be put into directing the orderly flow of resources from Beijing and Tianjin to cities in Hebei and promoting a balanced economic flow among cities,thus facilitating the coordination of regional development.
基金Supported by Scientific Resarch Program of Humanities and Social Sciences launched by Hubei Provincial Department of Education(2009b530)~~
文摘Spatial structure of rural tourism in the urban agglomerations of Wuhan was analyzed by comprehensively studying relevant documents about rural tourism,and reviewing previous researches on the concept and spatial structure of rural tourism.Through investigating rural tourist resources in the study area,resource advantages and characteristics of 9 cities were introduced,and the Gini Coefficient was taken to quantitatively analyze spatial patterns of its rural tourist villages,the obviously imbalanced concentration of these villages was pointed out.By measuring connectivity and accessibility of regional spaces in the study area,its traffic connectivity was proved moderate,and accessibility of each tourist village and town was fine.Then an optimized spatial structure was proposed for the rural tourism development in Wuhan Urban Agglomerations,that is,"one core,one belt and three districts".
基金Under the auspices of National Key Research and Development Program of China(No.2017YFC0212301,2016YFC0203304)Basic Research Funds of Central Public Welfare Research Institutes(No.2018SYIAEZD4)+3 种基金Program of Liaoning Meteorological Office(No.201904,D201603)Key Program of National Natural Science Foundation of China(No.41730647)Program of Laboratory of Atmospheric Chemistry,China Meteorological Administration(No.2017B02)Key Program of Natural Science Foundation of Liaoning Province(No.20170520359)
文摘Characteristics of air pollution in Northeast China(NEC) received less research attention in the past comparing to other heavily polluted regions in China.Spatiotemporal variations of six criteria air pollutants(PM10, PM2.5, SO2, NO2, O3 and CO) in Central Liaoning Urban Agglomeration(CLUA) and Harbin-Changchun Urban Agglomeration(HCUA) in NEC Plain were analyzed in this study based on three-year hourly observations of air pollutants and meteorological variables from 2015 to 2017.The results indicated that the annual mean concentrations of air pollutants are generally higher in the middle and southern regions in NEC Plain and lower in the northern region.Megacities such as Shenyang, Harbin and Changchun experience severe air pollution, with a three-year averaged air quality index(AQI) larger than 80, far exceeding the daily AQI standard at the first-level of 50 in China.The annual mean PM and SO2 concentrations decrease most significantly in NEC urban agglomerations from 2015 to 2017, followed by CO and NO2, while O3 shows a slight increasing trend.All the six pollutants exhibit obvious seasonal and diurnal variations, and these variations are dictated by local emission and meteorological conditions.PM2.5 and O3 concentrations in NEC urban agglomerations strongly depend on wind conditions.High O3 concentrations at different cities usually occur in presence of strong winds but are independent on wind direction(WD), while high PM2.5 is usually accompanied by weak winds and poor dispersion condition, and sometimes also occur when the northerly or southerly winds are strong.Regional transport of air pollutants between NEC urban agglomerations is common.A severe haze event on November 1–4, 2017 is examined to demonstrate the role of regional transport on pollution.
