This study addresses sustainable transportation in the Texas Urban Triangle at the regional scale. Its aim is to determine the most suitable corridor for new transport infrastructure by employing a spatial decision su...This study addresses sustainable transportation in the Texas Urban Triangle at the regional scale. Its aim is to determine the most suitable corridor for new transport infrastructure by employing a spatial decision support system proposed in this project. The system is being tested through its application to a prototype corridor parallel to Interstate 35 between San Antonio and Austin. The basic research questions asked are spatial in nature, so accordingly the geographic information system is the primary method of data analysis. The overall modeling approach is devoted to answering the following questions: What are the considerations to support sustainable growth? What scale or type of infrastructure is necessary? And how to adequately model the transportation corridors to meet the demands and to sustain the living environment at the same time?展开更多
Cropland elevation uplift(CLEU) has recently become a new challenge for agricultural modernization,food security,and sustainable cropland use in China.Uncovering the rules of CLEU is of great theoretical and practical...Cropland elevation uplift(CLEU) has recently become a new challenge for agricultural modernization,food security,and sustainable cropland use in China.Uncovering the rules of CLEU is of great theoretical and practical significance for China’s sustainable agricultural development and rural revitalization strategy.However,existing studies lack in-depth disclosure of multi-scale CLEU evolution rules,making it difficult to support the formulation of specific cropland protection policies.We analyzed the spatio-temporal evolution and multiscale CLEU in China from 1980 to 2020 using the Lorenz curve,gravity center model,hotspot analysis,and cropland elevation spectrum.The results indicated that the center of gravity of cropland moved to the northeast from 1980 to 2000 and then shifted to the northwest.The spatial distribution of cropland became increasingly imbalanced from 1980 to 2000.The change hotspots clustered in the northwest and the northeast,whereas cold-spots were mainly in southeastern China.The average elevation of cropland increased by 17.38 m,and the elevation uplift rule in different regions differed evidently across scales.From 1980 to 2000,all provinces except Xinjiang,Inner Mongolia,Gansu,and Yunnan exhibited CLEU,with Qinghai,Tibet,Beijing,and Guangdong showing the most noticeable uplifting.The CLEU can alleviate the shortage of cropland to some extent.However,without a planning constraint,the CLEU will lead to the increase of ecological risk and food security risk.展开更多
Hazard mitigation plans address hazards such as earthquakes,hurricanes,landslides,tornados,flooding more explicitly than pandemics or other public health crises.This paper analyzes and identifies pandemic-related miti...Hazard mitigation plans address hazards such as earthquakes,hurricanes,landslides,tornados,flooding more explicitly than pandemics or other public health crises.This paper analyzes and identifies pandemic-related mitigation strategies in state-level hazard mitigation plans across the United States.This study identifies common and uncommon strategies that could be included in plan updates such as:use of personal protective equipment(PPE),self-isolation/quarantine,hygiene,restricted gatherings,vaccination,vulnerability assessment,economic consequences analysis,acknowledging the need to address pandemics,and referring Centers for Disease Control and Prevention(CDC)guidelines.The 54 statelevel plans are compared based on their inclusion of the nine strategies.Findings show that vaccination,self-isolation/quarantine,and vulnerability assessment are the strategies most listed in plans.Additional concerns made evident by the 2020 coronavirus pandemic,such as contact tracing,environmental impact,and public services,were limited across the plans.It was concluded that long-term mitigation strategies for reducing the risk and speed of spread such as identifying strategic locations for testing,vaccination,and quarantine should be devised and implemented.Pandemics should be included as a distinct class of hazards while formulating state hazard mitigation plans.Strategies for addressing the impact of long working hours on the mental health of healthcare workers should be explored.Economic and psychological impact of unavailability of essential public services,such as transport and groceries,should be investigated and strategies should be formulated in the mitigation plans accordingly.展开更多
Under the framework of ecological civilisation,the formulation of territorial spatial planning(TSP) and improvement of spatial governance systems are of great practical significance.Since the founding of the People’s...Under the framework of ecological civilisation,the formulation of territorial spatial planning(TSP) and improvement of spatial governance systems are of great practical significance.Since the founding of the People’s Republic of China,land-use planning(LUP) has experienced profound changes,and tremendous research efforts have been made in that field.However,systematic studies on LUP history are scarce.To bridge the existing gap,this study traced back to the emergence of LUP,described its practice stages,and analysed the evolution of its classification system and methods.Further,the three rounds of general LUP practice and the current TSP over the past 40 years of the reform and opening-up have been discussed.The evolution of LUP was found to be closely related to economic development and could be broadly divided into four stages.The development of land-use classification in China has been slow and can be divided into five stages according to the evolution of the land classification system and important historical events.The development of LUP methods can be divided into two stages,before and after 1978.Since the economic reform,China has successively conducted three rounds of general LUP under different institutional and policy backgrounds.Future development should aim to innovate the theories and methods of TSP with Chinese characteristics and promote the study of village planning and the construction of TSP systems to achieve rural revitalisation and ecological civilisation.展开更多
The connectedness between cities has become one of the most widely discussed topics in urban and regional research in the mobile and big data era. One problem identified is the asymmetric city connectivity, partially ...The connectedness between cities has become one of the most widely discussed topics in urban and regional research in the mobile and big data era. One problem identified is the asymmetric city connectivity, partially due to data availability. We present a data-driven approach based on location and toponym(place name) extracted from social media data, to assess the asymmetric connectivity between cities. The assumption is that a higher frequency of occurrences of the name of city i in posts located in city j would imply that the city i is more influential than other cities upon city j. In addition, we’ve developed a group of measurements such as the relatedness index, impact index, link strength index, dependence index, and structure similar index to characterize such interactions. This framework of connectivity measurements can also be used to support smart planning taking into account the evolving interplay among cities. The space-time structure of urban systems in China is examined as the case study.展开更多
This paper develops a social media-disaster resilience analysis framework by categorizing types of social media use and their challenges to better understand and assess its role in disaster resilience research and man...This paper develops a social media-disaster resilience analysis framework by categorizing types of social media use and their challenges to better understand and assess its role in disaster resilience research and management.The framework is derived primarily from several case studies of Twitter use in three hurricane events in the United States-Hurricanes Isaac,Sandy,and Harvey.The paper first outlines four major contributions of social media data for disaster resilience research and management,which include serving as an effective communication platform,providing ground truth information for emergency response and rescue operations,providing information on people's sentiments,and allowing predictive modeling.However,there are four_key challenges to its uses,which include,easy spreading of false information,social and geographical disparities of Twitter use,technical issues on processing and analyzing big and noisy data,especially on improving the locational accuracy of the tweets,and algorithm bias in Al and other types of modeling.Then,the paper proposes twenty strategies that the four sectors of the social media community-organizations,individuals,social media companies,and researchers-could take to improve social media use to increase disaster resilience.展开更多
This paper presents a pilot effort to identify a methodology to more efficiently codify, quantify and illustrate the intrinsic values associated with ecological resources as expressed by stakeholders. Existing methodo...This paper presents a pilot effort to identify a methodology to more efficiently codify, quantify and illustrate the intrinsic values associated with ecological resources as expressed by stakeholders. Existing methodologies examine the value of ecological resources, but are often criticized for their monetary focus. These methods generally produce quasi-market values for non-market resources. The natural and cultural resources associated with a national park are analyzed in terms of the expressed values of active stakeholders to quantitatively produce multiple dimensions of value for each resource relative to all others. The resulting abstract and graphical value-space quantitatively reflects stakeholder participation, reflects non-market intrinsic value, and proactively contributes to environmental management and decision making.展开更多
The number of urban vitality assessment studies is rising continuously,owing to the emergence of geographic data.The current literature focuses primarily on evaluation,rather than implementation,of urban vitality.Henc...The number of urban vitality assessment studies is rising continuously,owing to the emergence of geographic data.The current literature focuses primarily on evaluation,rather than implementation,of urban vitality.Hence,a scoping review and research agenda are needed for urban vitality research to be more practical.This study aims to fill the research gap by exploring the content and methods of vitality assessment that can make urban vitality research more compatible with policy,planning,and design practice.We chose the neighborhood scale,which is the most practical initiative unit for vitality enhancement.We discovered that the gaps between the current research and practice primarily lie in the diversity of research subjects,the authenticity and comprehensiveness of vitality measurement,and the multi-domain of impact factor analysis.On this basis,we classified the following expandable aspects:(1) multi-type,multi-dimensional,multi-temporal,and implementation-adaptive vitality evaluation;(2) methods reflecting high-quality social interactions and the perceptions of vulnerable groups;(3) how design and urban management impacts vitality;and(4) the synergistic effects of multiple indicators on vitality.Overall,the research content and methodology presented in this paper can help neighborhood-scale vitality assessment to provide more meaningful insights for policy makers and practitioners.展开更多
Socialmedia such as Twitter is increasingly beingused as an effective platform to observe human behaviors in disastrous events.However,uneven social media use among different groups of population in different regions ...Socialmedia such as Twitter is increasingly beingused as an effective platform to observe human behaviors in disastrous events.However,uneven social media use among different groups of population in different regions could lead to biased consequences and affect disaster resilience.This paper studies the Twitter use during 2017 Hurricane Harvey in 76 counties in Texas and Louisiana.We seek to answer a fundamental question:did socialgeographical disparities of Twitter use exist during the three phases of emergency management(preparedness,response,recovery)?We employed a Twitter data mining framework to process the data and calculate two indexes:Ratio and Sentiment.Regression analyses between the Ratio indexes and the social-geographical characteristics of the counties at the three phrases reveal significant social and geographical disparities in Twitter use during Hurricane Harvey.Communities with higher disasterrelated Twitter use in Harvey generally were communities having better social and geographical conditions.These results of Twitter use patterns can be used to compare with future similar studies to see whether the Twitter use disparities have increased or decreased.Future research is also needed to examine the effects of Twitter use disparities on disaster resilience and to test whether Twitter use can predict community resilience.展开更多
This study reveals the human mobility from various sources and the luxury nature of social distancing in the U.S during the COVID-19 pandemic by highlighting the disparities in mobility dynamics from lower-income and ...This study reveals the human mobility from various sources and the luxury nature of social distancing in the U.S during the COVID-19 pandemic by highlighting the disparities in mobility dynamics from lower-income and upper-income counties.We collect,process,and compute mobility data from four different sources.We further design a Responsive Index(RI)based on the time series of mobility change percentages to quantify the general degree of mobility-based responsiveness to COVID-19 at the U.S.county level.We find statistically significant positive correlations in the RI between either two data sources,revealing their general similarity,albeit with varying Pearson’s r coefficients.Despite the similarity,however,mobility from each source presents unique and even contrasting characteristics,in part demonstrating the multifaceted nature of human mobility.The results suggest that counties with higher income tend to react more aggressively in terms of reducing more mobility in response to the COVID-19 pandemic.Most states present a positive difference in RI between their upper-income and lower-income counties,where diverging patterns in time series of mobility changes percentages can be found.The findings shed light on not only the characteristics of multi-source mobility data but also the mobility patterns in tandem with the economic disparity.展开更多
Inter-city mobility is one of the most important issues in the UN Sustainable Development Goals,as it is essential to access the regional labour market,goods and services,and to constrain the spread of infectious dise...Inter-city mobility is one of the most important issues in the UN Sustainable Development Goals,as it is essential to access the regional labour market,goods and services,and to constrain the spread of infectious diseases.Although the gravity model has been proved to be an effective model to describe mobility among settlements,knowledge is still insufficient in regions where dozens of megacities interact closely and over 100 million people reside.In addition,the existing knowledge is limited to overall population mobility,while the difference in inter-city travel with different purposes is unexplored on such a large geographic scale.We revisited the gravity laws of inter-city mobility using the 2.12 billion trip chains recorded by 40.48 million mobile phone users’trajectories in the Jing-Jin-Ji Region,which contains China’s capital Beijing.Firstly,unlike previous studies,we found that non-commuting rather than commuting is the dominant type of inter-city mobility(89.3%).Noncommuting travellers have a travel distance 42.3%longer than commuting travellers.Secondly,we developed more accurate gravity models for the spatial distribution of inter-city commuting and non-commuting travel.We also found that inter-city mobility has a hierarchical structure,as the distribution of inter-city travel volume follows Zipf’s law.In particular,the hierarchy of non-commuting travel volume among the cities is more in line with an ideal Zipf distribution than commuting travel.Our findings contribute to new knowledge on basic inter-city mobility laws,and they have significant applications for regional policies on human mobility.展开更多
China has experienced rapid car-oriented suburbanization during the past decades and is facing emerging challenges such as traffic congestion,air pollution,and even health threats.Learning from North American cities,C...China has experienced rapid car-oriented suburbanization during the past decades and is facing emerging challenges such as traffic congestion,air pollution,and even health threats.Learning from North American cities,Chinese cities have started adopting and implementing a Transit-Oriented Development(TOD) strategy,which encourages the transit ridership and walking trips by creating a pedestrian-friendly urban environment.Although much research has examined the walking environment in various neighborhoods or communities,few existing studies have examined the walking environment around transit stations,especially using micro-level data,such as walking infrastructure variables.This research chooses several infrastructure variables that are critical for pedestrians to investigate the walking environment around stations of the Bus Rapid Transit(BRT) No.1 Line in Xiamen City,China.This study defines a half mile buffer centered on each station as the spatial unit of analysis.The Geographic Information System(GIS) and field audits are employed to measure the characteristics of the infrastructure for pedestrians in each spatial unit of analysis.The results of this analysis can help assess the existing conditions of the infrastructure for pedestrians in each station area,which might need to be added or improved.The findings will not only provide empirical support for improving TODs in Xiamen,but also offer a lesson on how areas around transit stations could be retrofitted to improve the pedestrian environment.展开更多
文摘This study addresses sustainable transportation in the Texas Urban Triangle at the regional scale. Its aim is to determine the most suitable corridor for new transport infrastructure by employing a spatial decision support system proposed in this project. The system is being tested through its application to a prototype corridor parallel to Interstate 35 between San Antonio and Austin. The basic research questions asked are spatial in nature, so accordingly the geographic information system is the primary method of data analysis. The overall modeling approach is devoted to answering the following questions: What are the considerations to support sustainable growth? What scale or type of infrastructure is necessary? And how to adequately model the transportation corridors to meet the demands and to sustain the living environment at the same time?
基金sponsored in part by the National Natural Science Foundation of China (Grant No.42001187)Scientific Research Project of Education Department of Hubei Province (No.B2022262)。
文摘Cropland elevation uplift(CLEU) has recently become a new challenge for agricultural modernization,food security,and sustainable cropland use in China.Uncovering the rules of CLEU is of great theoretical and practical significance for China’s sustainable agricultural development and rural revitalization strategy.However,existing studies lack in-depth disclosure of multi-scale CLEU evolution rules,making it difficult to support the formulation of specific cropland protection policies.We analyzed the spatio-temporal evolution and multiscale CLEU in China from 1980 to 2020 using the Lorenz curve,gravity center model,hotspot analysis,and cropland elevation spectrum.The results indicated that the center of gravity of cropland moved to the northeast from 1980 to 2000 and then shifted to the northwest.The spatial distribution of cropland became increasingly imbalanced from 1980 to 2000.The change hotspots clustered in the northwest and the northeast,whereas cold-spots were mainly in southeastern China.The average elevation of cropland increased by 17.38 m,and the elevation uplift rule in different regions differed evidently across scales.From 1980 to 2000,all provinces except Xinjiang,Inner Mongolia,Gansu,and Yunnan exhibited CLEU,with Qinghai,Tibet,Beijing,and Guangdong showing the most noticeable uplifting.The CLEU can alleviate the shortage of cropland to some extent.However,without a planning constraint,the CLEU will lead to the increase of ecological risk and food security risk.
文摘Hazard mitigation plans address hazards such as earthquakes,hurricanes,landslides,tornados,flooding more explicitly than pandemics or other public health crises.This paper analyzes and identifies pandemic-related mitigation strategies in state-level hazard mitigation plans across the United States.This study identifies common and uncommon strategies that could be included in plan updates such as:use of personal protective equipment(PPE),self-isolation/quarantine,hygiene,restricted gatherings,vaccination,vulnerability assessment,economic consequences analysis,acknowledging the need to address pandemics,and referring Centers for Disease Control and Prevention(CDC)guidelines.The 54 statelevel plans are compared based on their inclusion of the nine strategies.Findings show that vaccination,self-isolation/quarantine,and vulnerability assessment are the strategies most listed in plans.Additional concerns made evident by the 2020 coronavirus pandemic,such as contact tracing,environmental impact,and public services,were limited across the plans.It was concluded that long-term mitigation strategies for reducing the risk and speed of spread such as identifying strategic locations for testing,vaccination,and quarantine should be devised and implemented.Pandemics should be included as a distinct class of hazards while formulating state hazard mitigation plans.Strategies for addressing the impact of long working hours on the mental health of healthcare workers should be explored.Economic and psychological impact of unavailability of essential public services,such as transport and groceries,should be investigated and strategies should be formulated in the mitigation plans accordingly.
基金National Natural Science Foundation of China,No.42001187。
文摘Under the framework of ecological civilisation,the formulation of territorial spatial planning(TSP) and improvement of spatial governance systems are of great practical significance.Since the founding of the People’s Republic of China,land-use planning(LUP) has experienced profound changes,and tremendous research efforts have been made in that field.However,systematic studies on LUP history are scarce.To bridge the existing gap,this study traced back to the emergence of LUP,described its practice stages,and analysed the evolution of its classification system and methods.Further,the three rounds of general LUP practice and the current TSP over the past 40 years of the reform and opening-up have been discussed.The evolution of LUP was found to be closely related to economic development and could be broadly divided into four stages.The development of land-use classification in China has been slow and can be divided into five stages according to the evolution of the land classification system and important historical events.The development of LUP methods can be divided into two stages,before and after 1978.Since the economic reform,China has successively conducted three rounds of general LUP under different institutional and policy backgrounds.Future development should aim to innovate the theories and methods of TSP with Chinese characteristics and promote the study of village planning and the construction of TSP systems to achieve rural revitalisation and ecological civilisation.
基金Under the auspices of National Natural Science Foundation of China(No.41801378,42071382)the Open Fund of Key Laboratory of Urban Land Resources Monitoring and Simulation,Ministry of Natural Resources(No.KF-2019-04-033)。
文摘The connectedness between cities has become one of the most widely discussed topics in urban and regional research in the mobile and big data era. One problem identified is the asymmetric city connectivity, partially due to data availability. We present a data-driven approach based on location and toponym(place name) extracted from social media data, to assess the asymmetric connectivity between cities. The assumption is that a higher frequency of occurrences of the name of city i in posts located in city j would imply that the city i is more influential than other cities upon city j. In addition, we’ve developed a group of measurements such as the relatedness index, impact index, link strength index, dependence index, and structure similar index to characterize such interactions. This framework of connectivity measurements can also be used to support smart planning taking into account the evolving interplay among cities. The space-time structure of urban systems in China is examined as the case study.
基金supported by U.S.National Science Foundation:[Grant Number Award#:1762600 and 1620451].
文摘This paper develops a social media-disaster resilience analysis framework by categorizing types of social media use and their challenges to better understand and assess its role in disaster resilience research and management.The framework is derived primarily from several case studies of Twitter use in three hurricane events in the United States-Hurricanes Isaac,Sandy,and Harvey.The paper first outlines four major contributions of social media data for disaster resilience research and management,which include serving as an effective communication platform,providing ground truth information for emergency response and rescue operations,providing information on people's sentiments,and allowing predictive modeling.However,there are four_key challenges to its uses,which include,easy spreading of false information,social and geographical disparities of Twitter use,technical issues on processing and analyzing big and noisy data,especially on improving the locational accuracy of the tweets,and algorithm bias in Al and other types of modeling.Then,the paper proposes twenty strategies that the four sectors of the social media community-organizations,individuals,social media companies,and researchers-could take to improve social media use to increase disaster resilience.
文摘This paper presents a pilot effort to identify a methodology to more efficiently codify, quantify and illustrate the intrinsic values associated with ecological resources as expressed by stakeholders. Existing methodologies examine the value of ecological resources, but are often criticized for their monetary focus. These methods generally produce quasi-market values for non-market resources. The natural and cultural resources associated with a national park are analyzed in terms of the expressed values of active stakeholders to quantitatively produce multiple dimensions of value for each resource relative to all others. The resulting abstract and graphical value-space quantitatively reflects stakeholder participation, reflects non-market intrinsic value, and proactively contributes to environmental management and decision making.
基金National Natural Science Foundation of China,No.51908495。
文摘The number of urban vitality assessment studies is rising continuously,owing to the emergence of geographic data.The current literature focuses primarily on evaluation,rather than implementation,of urban vitality.Hence,a scoping review and research agenda are needed for urban vitality research to be more practical.This study aims to fill the research gap by exploring the content and methods of vitality assessment that can make urban vitality research more compatible with policy,planning,and design practice.We chose the neighborhood scale,which is the most practical initiative unit for vitality enhancement.We discovered that the gaps between the current research and practice primarily lie in the diversity of research subjects,the authenticity and comprehensiveness of vitality measurement,and the multi-domain of impact factor analysis.On this basis,we classified the following expandable aspects:(1) multi-type,multi-dimensional,multi-temporal,and implementation-adaptive vitality evaluation;(2) methods reflecting high-quality social interactions and the perceptions of vulnerable groups;(3) how design and urban management impacts vitality;and(4) the synergistic effects of multiple indicators on vitality.Overall,the research content and methodology presented in this paper can help neighborhood-scale vitality assessment to provide more meaningful insights for policy makers and practitioners.
基金the SBE Office of Multidisciplinary Activities(SMA)organization in Interdisciplinary Behavioral and Social Science Research(IBSS)Program(Award No.1620451)the NSF Social and Economic Sciences Division(SES)Hurricane Harvey 2017 Program(Award No.1762600)。
文摘Socialmedia such as Twitter is increasingly beingused as an effective platform to observe human behaviors in disastrous events.However,uneven social media use among different groups of population in different regions could lead to biased consequences and affect disaster resilience.This paper studies the Twitter use during 2017 Hurricane Harvey in 76 counties in Texas and Louisiana.We seek to answer a fundamental question:did socialgeographical disparities of Twitter use exist during the three phases of emergency management(preparedness,response,recovery)?We employed a Twitter data mining framework to process the data and calculate two indexes:Ratio and Sentiment.Regression analyses between the Ratio indexes and the social-geographical characteristics of the counties at the three phrases reveal significant social and geographical disparities in Twitter use during Hurricane Harvey.Communities with higher disasterrelated Twitter use in Harvey generally were communities having better social and geographical conditions.These results of Twitter use patterns can be used to compare with future similar studies to see whether the Twitter use disparities have increased or decreased.Future research is also needed to examine the effects of Twitter use disparities on disaster resilience and to test whether Twitter use can predict community resilience.
基金supported by University of South Carolina COVID-19 Internal Funding Initiative[Grant Number 135400-20-54176]National Institutes of Health(NIH)[Grant Number 3R01AI127203-04S1]National Science Foundation(NSF)[Grant Number 2028791].
文摘This study reveals the human mobility from various sources and the luxury nature of social distancing in the U.S during the COVID-19 pandemic by highlighting the disparities in mobility dynamics from lower-income and upper-income counties.We collect,process,and compute mobility data from four different sources.We further design a Responsive Index(RI)based on the time series of mobility change percentages to quantify the general degree of mobility-based responsiveness to COVID-19 at the U.S.county level.We find statistically significant positive correlations in the RI between either two data sources,revealing their general similarity,albeit with varying Pearson’s r coefficients.Despite the similarity,however,mobility from each source presents unique and even contrasting characteristics,in part demonstrating the multifaceted nature of human mobility.The results suggest that counties with higher income tend to react more aggressively in terms of reducing more mobility in response to the COVID-19 pandemic.Most states present a positive difference in RI between their upper-income and lower-income counties,where diverging patterns in time series of mobility changes percentages can be found.The findings shed light on not only the characteristics of multi-source mobility data but also the mobility patterns in tandem with the economic disparity.
基金supported by the National Natural Science Foundation of China(Grant Nos.41925003&42130402)the Beijing Municipal Social Science Foundation(Grant No.20JCB073)。
文摘Inter-city mobility is one of the most important issues in the UN Sustainable Development Goals,as it is essential to access the regional labour market,goods and services,and to constrain the spread of infectious diseases.Although the gravity model has been proved to be an effective model to describe mobility among settlements,knowledge is still insufficient in regions where dozens of megacities interact closely and over 100 million people reside.In addition,the existing knowledge is limited to overall population mobility,while the difference in inter-city travel with different purposes is unexplored on such a large geographic scale.We revisited the gravity laws of inter-city mobility using the 2.12 billion trip chains recorded by 40.48 million mobile phone users’trajectories in the Jing-Jin-Ji Region,which contains China’s capital Beijing.Firstly,unlike previous studies,we found that non-commuting rather than commuting is the dominant type of inter-city mobility(89.3%).Noncommuting travellers have a travel distance 42.3%longer than commuting travellers.Secondly,we developed more accurate gravity models for the spatial distribution of inter-city commuting and non-commuting travel.We also found that inter-city mobility has a hierarchical structure,as the distribution of inter-city travel volume follows Zipf’s law.In particular,the hierarchy of non-commuting travel volume among the cities is more in line with an ideal Zipf distribution than commuting travel.Our findings contribute to new knowledge on basic inter-city mobility laws,and they have significant applications for regional policies on human mobility.
基金funded by the National Science Foundation of China(Grant No.51508208)
文摘China has experienced rapid car-oriented suburbanization during the past decades and is facing emerging challenges such as traffic congestion,air pollution,and even health threats.Learning from North American cities,Chinese cities have started adopting and implementing a Transit-Oriented Development(TOD) strategy,which encourages the transit ridership and walking trips by creating a pedestrian-friendly urban environment.Although much research has examined the walking environment in various neighborhoods or communities,few existing studies have examined the walking environment around transit stations,especially using micro-level data,such as walking infrastructure variables.This research chooses several infrastructure variables that are critical for pedestrians to investigate the walking environment around stations of the Bus Rapid Transit(BRT) No.1 Line in Xiamen City,China.This study defines a half mile buffer centered on each station as the spatial unit of analysis.The Geographic Information System(GIS) and field audits are employed to measure the characteristics of the infrastructure for pedestrians in each spatial unit of analysis.The results of this analysis can help assess the existing conditions of the infrastructure for pedestrians in each station area,which might need to be added or improved.The findings will not only provide empirical support for improving TODs in Xiamen,but also offer a lesson on how areas around transit stations could be retrofitted to improve the pedestrian environment.