To adapt to national climate change strategies,understanding the thermal vulnerability of urban functional zones(UFZs)is critical for enhancing the livability and sustainable development of cities.We address the limit...To adapt to national climate change strategies,understanding the thermal vulnerability of urban functional zones(UFZs)is critical for enhancing the livability and sustainable development of cities.We address the limitations of existing thermal vulnerability assessments by incorporating human perception into the analysis.Specifically,we introduce the sky openness index to reflect human perception of the thermal environment and examine variations in thermal vulnerability across different UFZs.Using the Extreme Gradient Boosting(XGBoost)-SHapley Additive exPlanations(SHAP)model,we analyze the contributions of 2D and 3D urban form indicators to thermal vulnerability and link these contributions to the unique needs and vulnerability characteristics of UFZs of Foshan City,China in 2023.The results reveal that:1)high-value heat-fragile areas(1.74–2.00]constitute 10.42%of Foshan City;2)traffic zone and publiccommercial zone exhibit the highest levels of thermal vulnerability;and 3)building height and the normalized building index are the most influential factors,with contributions of|0.06|and|0.03|,respectively.We provide a scientific foundation for developing governance strategies to promote urban resilience.展开更多
Urban functional area(UFA)is a core scientific issue affecting urban sustainability.The current knowledge gap is mainly reflected in the lack of multi-scale quantitative interpretation methods from the perspective of ...Urban functional area(UFA)is a core scientific issue affecting urban sustainability.The current knowledge gap is mainly reflected in the lack of multi-scale quantitative interpretation methods from the perspective of human-land interaction.In this paper,based on multi-source big data include 250 m×250 m resolution cell phone data,1.81×105 Points of Interest(POI)data and administrative boundary data,we built a UFA identification method and demonstrated empirically in Shenyang City,China.We argue that the method we built can effectively identify multi-scale multi-type UFAs based on human activity and further reveal the spatial correlation between urban facilities and human activity.The empirical study suggests that the employment functional zones in Shenyang City are more concentrated in central cities than other single functional zones.There are more mix functional areas in the central city areas,while the planned industrial new cities need to develop comprehensive functions in Shenyang.UFAs have scale effects and human-land interaction patterns.We suggest that city decision makers should apply multi-sources big data to measure urban functional service in a more refined manner from a supply-demand perspective.展开更多
Urbanization significantly increases the risk of urban flooding. Therefore, quantitative study of urban rainfall-runoff processes can provide a scientific basis for urban planning and management. In this paper, the bu...Urbanization significantly increases the risk of urban flooding. Therefore, quantitative study of urban rainfall-runoff processes can provide a scientific basis for urban planning and management. In this paper, the built-up region within the Fifth Ring Road of Beijing was selected as the study area. The details of land cover and urban function zones(UFZs) were identified using GIS and RS methods. On this basis, the SCS-CN model was adopted to analyze the rainfall-runoff risk characteristics of the study area. The results showed that:(1) UFZs within different levels of runoff risk varied under different rainfall conditions. The area ratio of the UFZs with high runoff risk increased from 18.90%(for rainfall return period of 1 a) to 54.74%(for period of 100 a). Specifically, urban commercial areas tended to have the highest runoff risk, while urban greening spaces had the lowest.(2) The spatial characteristics of the runoff risks showed an obvious circular distribution. Spatial cluster areas with high runoff risk were mainly concentrated in the center of the study area, while those with low runoff risk were mainly distributed between the fourth and fifth ring roads. The results indicated that the spatial clustering characteristic of urban runoff risk and runoff heterogeneity among different UFZs should be fully considered during urban rainwater management.展开更多
The classification of urban functional areas plays an important role in urban planning and resource management.Although previous studies have confirmed that different urban func-tional areas have different morphologic...The classification of urban functional areas plays an important role in urban planning and resource management.Although previous studies have confirmed that different urban func-tional areas have different morphological structures and Land Surface Temperature(LST)characteristics,these two types of characteristics have rarely been fully integrated and used for functional area classification.In this paper,a new framework for classifying urban functional areas is proposed by combining urban morphological features and LST features.First,metrics are constructed from three levels,namely,building,road and region,which are used to portray urban morphology;LST is retrieved using thermal infrared remote sensing to reflect LST features with four metrics:the average temperature,maximum temperature,temperature difference and standard deviation of temperature.Then,the functional areas are classified into four categories:service/public land,commercial land,residential land and industrial land.A random forest algorithm is used to effectively fuse the features of these two categories and classify the functional areas.The effectiveness of the proposed framework is tested in the study area of Shenzhen City,Guangdong Province.The results show that the combined classification accuracy of the proposed classification method is 0.85,which is 0.26 higher than that of the classification model based on urban morphology and 0.1 higher than that of the classification model based on LST features.The proposed framework verifies that the integration of LST features into urban functional area classification is reliable and effectively combines urban morphology and LST features for functional area classification.展开更多
Dam-break flows pose significant threats to urban areas due to their potential for causing rapid and extensive flooding. Traditional numerical methods for simulating these events struggle with complex urban landscapes...Dam-break flows pose significant threats to urban areas due to their potential for causing rapid and extensive flooding. Traditional numerical methods for simulating these events struggle with complex urban landscapes. This paper presents an alternative approach using Radial Basis Functions to simulate dam-break flows and their impact on urban flood inundation. The proposed method adapts a new strategy based on Particle Swarm Optimization for variable shape parameter selection on meshfree formulation to enhance the numerical stability and convergence of the simulation. The method’s accuracy and efficiency are demonstrated through numerical experiments, including well-known partial and circular dam-break problems and an idealized city with a single building, highlighting its potential as a valuable tool for urban flood risk management.展开更多
When various urban functions are integrated into one location,they form a mixture of functions.The emerging big data promote an alternative way to identify mixed functions.However,current methods are largely unable to...When various urban functions are integrated into one location,they form a mixture of functions.The emerging big data promote an alternative way to identify mixed functions.However,current methods are largely unable to extract deep features in these data,resulting in low accuracy.In this study,we focused on recognizing mixed urban functions from the perspective of human activities,which are essential indicators of functional areas in a city.We proposed a framework to comprehensively extract deep features of human activities in big data,including activity dynamics,mobility interactions,and activity semantics,through representation learning methods.Then,integrating these features,we employed fuzzy clustering to identify the mixture of urban functions.We conducted a case study using taxiflow and social media data in Beijing,China,in whichfive urban functions and their correlations with land use were recognized.The mixture degree of urban functions in each location was revealed,which had a negative correlation with taxi trip distance.The results confirmed the advantages of our method in understanding mixed urban functions by employing various representation learning methods to comprehensively depict human activities.This study has important implications for urban planners in understanding urban systems and developing better strategies.展开更多
Urban Functional Zones(UFZs)can be identified by measuring the spatiotemporal patterns of activities that occur within them.Geosocial media data possesses abundant spatial and temporal information for activity mining....Urban Functional Zones(UFZs)can be identified by measuring the spatiotemporal patterns of activities that occur within them.Geosocial media data possesses abundant spatial and temporal information for activity mining.Identifying UFZs from geosocial media data aids urban planning,infrastructure,resource allocation,and transportation modernization in the complex urban system.In this work,we proposed an integrated approach by combining the spatiotemporal clustering method with a machine learning classifier.The spatiotemporal clustering method was used to mine the spatiotemporal patterns of activities,of which the distinctive features were extracted as inputs into a machine learning classifier for UFZ identification.The results show that more than 80%of the UFZs can be correctly identified by our proposed method.It reveals that this work serves as a functional groundwork for future studies,facilitating the understanding of urban systems as well as promoting sustainable urban development.展开更多
Urban Functional Zone(UFZ)identification is vital for urban planning,renewal,and development.Point of Interest(POI),as one of the most popular data in UFZ studies,is transformed into a geo-corpus under specific sampli...Urban Functional Zone(UFZ)identification is vital for urban planning,renewal,and development.Point of Interest(POI),as one of the most popular data in UFZ studies,is transformed into a geo-corpus under specific sampling strategies,which can be used with Natural Language Processing(NLP)technology to extract geo-semantic features and identify UFZs.However,existing studies only capture a single spatial distribution pattern of POIs,while ignoring the other spatial distribution information.In this paper,we developed an integrated geo-corpus construction approach to capture multi-spatial distribution patterns of POIs that were represented by different modal POI embeddings.Subsequently,random forest model was leveraged to classify UFZs based on those embeddings.A set of combination experiments were designed for performance validation.The results show that our proposed method can effectively identify UFZs with an accuracy of 72.9%,with an improvement of 8.5%compared to the baseline methods.The outcome of this study will help urban planners to better understand UFZs through investigating the integrated spatial distribution patterns of POIs embedded in UFZs.展开更多
Under the background of increasing aggravation of social transformation,the paper has discussed the influence of new campus construction in large cities on the expansion of high education zone and college suburbanizat...Under the background of increasing aggravation of social transformation,the paper has discussed the influence of new campus construction in large cities on the expansion of high education zone and college suburbanization.Based on Merton's structural functionalism,by taking Xindu District of Chengdu City for example,the positive and negative functions of college suburbanization in suburb urbanization have been analyzed through complex indexes of urbanization evaluation.Furthermore,it has analyzed positive functions on urbanization of suburb population,suburb economy,suburb residents' life style and values,as well as negative functions on government's administration and land resources' use.On this basis,countermeasures to transform negative effects into positive effects have been proposed.展开更多
Rapid morphological and socioeconomic changes have accelerated the urbanization process and urban land use transformation in China.Megacities comprise clusters of urban cities and exhibit both newly formed and well-de...Rapid morphological and socioeconomic changes have accelerated the urbanization process and urban land use transformation in China.Megacities comprise clusters of urban cities and exhibit both newly formed and well-developed urban land use development beyond administrative boundaries.It is necessary to distinguish the changing effects of spatial-varying driving factors on newly formed urban land uses from well-developed built-up areas in megacities.This study proposed a multi-spatial urbanization framework to quantify region-level socioeconomics,cluster-level ecological morphologies,and grid-level urban functional morphologies.A three-level Bayesian hierarchical model was developed to investigate the impacts of multi-spatial driving factors on urban land use transformation in megacities.The study period focused on the urbanization process between 2000 and 2018 in Guangdong-Hong Kong-Macao Greater Bay Area(GBA).Results revealed that compared with well-developed urban built-up land,changing impacts of three-level driving factors in urban land use transformation could be captured based on the proposed Bayesian hierarchical model.The region-level total population was associated with increasing possibilities in forming new residential land than the well-developed ones in 35 districts/counties/cities in GBA.Cluster-level ecological attributes with higher proportion,lower edge density of urban built areas,and lower-degree ecological complexity showed increasing probability on newly formed industrial and public land.Grid-level urban functional factors including public transportation density and shopping/dining distribution exhibited significantly decreasing probability(coefficients:−2.12 to−0.51)on contributing newly formed land uses compared with the well-developed areas,whereas business/industry distribution represented higher(coefficients:0.99 and 0.15)and lower probabilities(coefficient:−0.22)of forming industrial/public land and residential land separately.This research shows a new attempt to distinguish multi-spatial morphological and socioeconomic effects in urban land use transformation in megacities.展开更多
Driven by the rapid development of urbanization in China,a large amount of inefficient land has been generated,and cities need to transform their extensive development methods.To achieve efficient urban development,th...Driven by the rapid development of urbanization in China,a large amount of inefficient land has been generated,and cities need to transform their extensive development methods.To achieve efficient urban development,the relevant departments implement urban renewal actions,and promote sustainable urban development.On the basis of analyzing the concept of urban renewal action,the history and background of urban renewal policies are analyzed,and different levels of policy guidance and priorities are sorted out.Several thoughts are put forward on urban renewal action,aiming to create a beautiful and comfortable urban space.It is hoped that this will have certain guiding significance for urban renewal in China.展开更多
The coordinated development of urban and rural territorial systems has long been a scientific issue of concern in geography and socioeconomic development in China.Based on Territorial Function Theory,this paper establ...The coordinated development of urban and rural territorial systems has long been a scientific issue of concern in geography and socioeconomic development in China.Based on Territorial Function Theory,this paper establishes a theoretical framework to support the coordinated development of urban and rural territorial systems,analyzes the trend of functional evolution,discusses the impact of efficient allocation and orderly element flow on system equivalence development,and puts forward approaches and policy suggestions for equilibrium development in the future.The main conclusions are as follows:(1)The evolution of urban and rural territorial functions has experienced four stages:rural to rural,rural to urban transition,rural to urban,and urban to urban.In this process,territorial functions have been developed to be hierarchical and advanced.(2)Functional evolution enables urban and rural comparative advantages to be transformed from value difference to value equivalence.Increasing the flow intensity and reconstructing the flow space have become the necessary conditions for the coordination of development.(3)Land is the most important resource in China,and land system reform is the key to achieving equivalence development of urban and rural territorial systems,thereby determining the future equilibrium development of the two systems.展开更多
Quantifying the degree of urban function mix has great signifi cance to both urban planning practices and studies. This paper, fi rst of all, based on the data of points of interest(POIs), analyzes the spatial distrib...Quantifying the degree of urban function mix has great signifi cance to both urban planning practices and studies. This paper, fi rst of all, based on the data of points of interest(POIs), analyzes the spatial distribution patterns of urban functions in Beijing. Then according to the taxi GPS data with the origin and destination points(taxi-ODs), we identify the spatial and temporal pattern of the degree of urban function mix in Beijing. Finally, based on the information entropy model of the POIs and taxi-ODs, we establish a spatial entropy and a temporal entropy to quantitatively assess the degree of urban function mix, confirming by virtue of correlation analysis and regression analysis that the spatial entropy of POIs is closely associated with the temporal entropy of taxi-ODs, which proves that it is reasonable to assess the degree of urban function mix via these two entropies. As a result, the degree of urban function mix in Beijing is characterized by slowly decreasing from its core area along the 3rd and 4th Ring Roads to its periphery. In detail, there is the highest degree of urban function mix in Beijing's traditional core areas, including Zhongguancun, CBD(Central Business District), the Old Dongcheng District, the Old Xicheng District, and the area within the 2nd Ring Road; a higher degree in Wangjing area; and a low degree in Tiantongyuan and Huilongguan communities. The analytical results have initially achieved a more accurate identifi cation and quantitative evaluation on the degree of urban function mix, and can be taken as a supporting tool to analyze the comprehensiveness of urban functions.展开更多
Since the 17th National Congress of the Communist Party of China, ecological civilization has been the key construction goal in China, which has a profound impact on the process of urbanization. In recent years, with ...Since the 17th National Congress of the Communist Party of China, ecological civilization has been the key construction goal in China, which has a profound impact on the process of urbanization. In recent years, with the rapid development of urbanization and unreasonable land development and utilization, the ecological environment has deteriorated sharply, and the stability of ecological environment has always been a difficult problem in the process of regional development. The spatial division of urban ecological function can be divided into different types of spatial utilization according to the fragile state of ecological environment, which not only guarantees urban construction but also maintains the ecological environment health, and has great economic benefits and ecological value in formulating regional development strategies and ecological protection. In this paper, from four perspectives of “land, water, human and forest”, eight factors affecting ecological sensitivity were selected, and GIS spatial superposition method was used to conduct qualitative and quantitative analysis on the ecological sensitivity of Baoji City, and the evaluation results of single factor ecological sensitivity and comprehensive ecological sensitivity were obtained. The areas with different ecological sensitivity are divided into extremely sensitive areas, highly sensitive areas, moderately sensitive areas, slightly sensitive areas and non-sensitive areas. The research shows that the proportion of extreme, high, moderate, mild and insensitive areas in Baoji City is 7.32%, 10.57%, 22.25%, 42.91% and 16.95% respectively. Finally, the areas with different sensitivity grades are identified as three types of urban ecological function areas: ecological conservation area, ecological coordinated moderate utilization area and ecological suitable construction area, so as to provide scientific theoretical basis for urban construction and land use optimization in Baoji City.展开更多
Rapid urbanization in Beijing stimulates the urban land expansion and diminishes available agricultural land. Monofunctional agricultural land use can not meet the demand of the devel- opment of the multifunctional ag...Rapid urbanization in Beijing stimulates the urban land expansion and diminishes available agricultural land. Monofunctional agricultural land use can not meet the demand of the devel- opment of the multifunctional agriculture and urbanization any more, so multifunctional agricultural land use is going to be promoted in the city. This article proposes the evolvement of the land use change from 1992 to 2004 and discusses some evolvement views.展开更多
This methodological investigation deals with measurement and valuation of ecological service functions for urban green space. Social, economic and ecological dimensions for such types of function were analyzed and a ...This methodological investigation deals with measurement and valuation of ecological service functions for urban green space. Social, economic and ecological dimensions for such types of function were analyzed and a concept “integrated ecological service functions” (IESF) was put forward for evaluation. Based upon this conceptual approach, an index system for measuring IESF for urban green space was established. With a methodological integration of fuzzy mathematics, decision making analysis and Delphi method, an AHP fuzzy evaluation techniques for IESF for urban green space, called AFIFUG method, was developed. Such a method has been directly applied to the land use strategic planning of Tianjin out ring green belt(TOGB), and its analysis results have been successfully put into operation.展开更多
From the perspective of balancing urban and rural development,this article researches the factors influencing the consumption level of rural residents in China.I select the relevant data concerning per capita net inco...From the perspective of balancing urban and rural development,this article researches the factors influencing the consumption level of rural residents in China.I select the relevant data concerning per capita net income of rural households and annual per capita consumer spending of rural residents for living in the period 1985-2008,establish the regression model of per capita net income of rural households and per capita consumer spending of rural residents for living,and conduct regression analysis and error correction model test using the measurement software.The analysis results show that there is not only long-term equilibrium relationship between rural residents' current consumption and rural residents' current income,between rural residents' consumption in lag period 1 and rural residents' income in lag period 1,but also short-term equilibrium relationship;current income is the main reason for determining the current consumption).Corresponding proposals are put forward to promote the level of rural consumption in China as follows:propel agricultural modernization;actively develop specialized cooperative organizations of rural residents;improve rural land transfer mechanism;promote the level of public services in rural areas;accelerate the transfer of rural surplus labor.展开更多
基金Under the auspices of Liaoning Revitalization Talents Program(No.XLYC2202024)Basic Scientific Research Project(Key Project)of the Education Department of Liaoning Province(No.LJ212410165084)the Fundamental Research Funds for the Central Universities(No.N2111003,N2411001)。
文摘To adapt to national climate change strategies,understanding the thermal vulnerability of urban functional zones(UFZs)is critical for enhancing the livability and sustainable development of cities.We address the limitations of existing thermal vulnerability assessments by incorporating human perception into the analysis.Specifically,we introduce the sky openness index to reflect human perception of the thermal environment and examine variations in thermal vulnerability across different UFZs.Using the Extreme Gradient Boosting(XGBoost)-SHapley Additive exPlanations(SHAP)model,we analyze the contributions of 2D and 3D urban form indicators to thermal vulnerability and link these contributions to the unique needs and vulnerability characteristics of UFZs of Foshan City,China in 2023.The results reveal that:1)high-value heat-fragile areas(1.74–2.00]constitute 10.42%of Foshan City;2)traffic zone and publiccommercial zone exhibit the highest levels of thermal vulnerability;and 3)building height and the normalized building index are the most influential factors,with contributions of|0.06|and|0.03|,respectively.We provide a scientific foundation for developing governance strategies to promote urban resilience.
基金Under the auspices of Natural Science Foundation of China(No.41971166)。
文摘Urban functional area(UFA)is a core scientific issue affecting urban sustainability.The current knowledge gap is mainly reflected in the lack of multi-scale quantitative interpretation methods from the perspective of human-land interaction.In this paper,based on multi-source big data include 250 m×250 m resolution cell phone data,1.81×105 Points of Interest(POI)data and administrative boundary data,we built a UFA identification method and demonstrated empirically in Shenyang City,China.We argue that the method we built can effectively identify multi-scale multi-type UFAs based on human activity and further reveal the spatial correlation between urban facilities and human activity.The empirical study suggests that the employment functional zones in Shenyang City are more concentrated in central cities than other single functional zones.There are more mix functional areas in the central city areas,while the planned industrial new cities need to develop comprehensive functions in Shenyang.UFAs have scale effects and human-land interaction patterns.We suggest that city decision makers should apply multi-sources big data to measure urban functional service in a more refined manner from a supply-demand perspective.
基金Major Program of National Natural Science Foundation of China,No.41590841Key Project for National Natural Science Foundation of China,No.41230633
文摘Urbanization significantly increases the risk of urban flooding. Therefore, quantitative study of urban rainfall-runoff processes can provide a scientific basis for urban planning and management. In this paper, the built-up region within the Fifth Ring Road of Beijing was selected as the study area. The details of land cover and urban function zones(UFZs) were identified using GIS and RS methods. On this basis, the SCS-CN model was adopted to analyze the rainfall-runoff risk characteristics of the study area. The results showed that:(1) UFZs within different levels of runoff risk varied under different rainfall conditions. The area ratio of the UFZs with high runoff risk increased from 18.90%(for rainfall return period of 1 a) to 54.74%(for period of 100 a). Specifically, urban commercial areas tended to have the highest runoff risk, while urban greening spaces had the lowest.(2) The spatial characteristics of the runoff risks showed an obvious circular distribution. Spatial cluster areas with high runoff risk were mainly concentrated in the center of the study area, while those with low runoff risk were mainly distributed between the fourth and fifth ring roads. The results indicated that the spatial clustering characteristic of urban runoff risk and runoff heterogeneity among different UFZs should be fully considered during urban rainwater management.
基金supported by the National Natural Science Foundation of China[grant Nos 41971406,41871292]the Science and Technology Program of Guangdong Province[grant number 2018B020207002]the Science and Technology Program of Guangzhou,China[grant number 201803030034].
文摘The classification of urban functional areas plays an important role in urban planning and resource management.Although previous studies have confirmed that different urban func-tional areas have different morphological structures and Land Surface Temperature(LST)characteristics,these two types of characteristics have rarely been fully integrated and used for functional area classification.In this paper,a new framework for classifying urban functional areas is proposed by combining urban morphological features and LST features.First,metrics are constructed from three levels,namely,building,road and region,which are used to portray urban morphology;LST is retrieved using thermal infrared remote sensing to reflect LST features with four metrics:the average temperature,maximum temperature,temperature difference and standard deviation of temperature.Then,the functional areas are classified into four categories:service/public land,commercial land,residential land and industrial land.A random forest algorithm is used to effectively fuse the features of these two categories and classify the functional areas.The effectiveness of the proposed framework is tested in the study area of Shenzhen City,Guangdong Province.The results show that the combined classification accuracy of the proposed classification method is 0.85,which is 0.26 higher than that of the classification model based on urban morphology and 0.1 higher than that of the classification model based on LST features.The proposed framework verifies that the integration of LST features into urban functional area classification is reliable and effectively combines urban morphology and LST features for functional area classification.
文摘Dam-break flows pose significant threats to urban areas due to their potential for causing rapid and extensive flooding. Traditional numerical methods for simulating these events struggle with complex urban landscapes. This paper presents an alternative approach using Radial Basis Functions to simulate dam-break flows and their impact on urban flood inundation. The proposed method adapts a new strategy based on Particle Swarm Optimization for variable shape parameter selection on meshfree formulation to enhance the numerical stability and convergence of the simulation. The method’s accuracy and efficiency are demonstrated through numerical experiments, including well-known partial and circular dam-break problems and an idealized city with a single building, highlighting its potential as a valuable tool for urban flood risk management.
基金supported by the National Natural Science Foundation of China[grant number 41971331].
文摘When various urban functions are integrated into one location,they form a mixture of functions.The emerging big data promote an alternative way to identify mixed functions.However,current methods are largely unable to extract deep features in these data,resulting in low accuracy.In this study,we focused on recognizing mixed urban functions from the perspective of human activities,which are essential indicators of functional areas in a city.We proposed a framework to comprehensively extract deep features of human activities in big data,including activity dynamics,mobility interactions,and activity semantics,through representation learning methods.Then,integrating these features,we employed fuzzy clustering to identify the mixture of urban functions.We conducted a case study using taxiflow and social media data in Beijing,China,in whichfive urban functions and their correlations with land use were recognized.The mixture degree of urban functions in each location was revealed,which had a negative correlation with taxi trip distance.The results confirmed the advantages of our method in understanding mixed urban functions by employing various representation learning methods to comprehensively depict human activities.This study has important implications for urban planners in understanding urban systems and developing better strategies.
基金supported by the Natural Sciences and Engineering Research Council of Canada[RGPIN-2017-05950]China Scholarship Council[03998521001]+1 种基金Beijing Categorized Development Quota Project[03082722002]Beijing University of Civil Engineering and Architecture Young Scholars’Research Ability Improvement Program[X21018]。
文摘Urban Functional Zones(UFZs)can be identified by measuring the spatiotemporal patterns of activities that occur within them.Geosocial media data possesses abundant spatial and temporal information for activity mining.Identifying UFZs from geosocial media data aids urban planning,infrastructure,resource allocation,and transportation modernization in the complex urban system.In this work,we proposed an integrated approach by combining the spatiotemporal clustering method with a machine learning classifier.The spatiotemporal clustering method was used to mine the spatiotemporal patterns of activities,of which the distinctive features were extracted as inputs into a machine learning classifier for UFZ identification.The results show that more than 80%of the UFZs can be correctly identified by our proposed method.It reveals that this work serves as a functional groundwork for future studies,facilitating the understanding of urban systems as well as promoting sustainable urban development.
基金supported by the China Scholarship Council[03998521001]the Beijing Categorized Development Quota Project[03082722002]+2 种基金the Beijing University of Civil Engineering and Architecture Young Scholars’Research Ability Improvement Program[X21018]the National Natural Science Foundation of China[41930650]the Natural Sciences and Engineering Research Council of Canada[RGPIN-2017-05950].
文摘Urban Functional Zone(UFZ)identification is vital for urban planning,renewal,and development.Point of Interest(POI),as one of the most popular data in UFZ studies,is transformed into a geo-corpus under specific sampling strategies,which can be used with Natural Language Processing(NLP)technology to extract geo-semantic features and identify UFZs.However,existing studies only capture a single spatial distribution pattern of POIs,while ignoring the other spatial distribution information.In this paper,we developed an integrated geo-corpus construction approach to capture multi-spatial distribution patterns of POIs that were represented by different modal POI embeddings.Subsequently,random forest model was leveraged to classify UFZs based on those embeddings.A set of combination experiments were designed for performance validation.The results show that our proposed method can effectively identify UFZs with an accuracy of 72.9%,with an improvement of 8.5%compared to the baseline methods.The outcome of this study will help urban planners to better understand UFZs through investigating the integrated spatial distribution patterns of POIs embedded in UFZs.
基金Supported by Social Science Planning Youth Project of Educational Department of Sichuan Province(09SB112)~~
文摘Under the background of increasing aggravation of social transformation,the paper has discussed the influence of new campus construction in large cities on the expansion of high education zone and college suburbanization.Based on Merton's structural functionalism,by taking Xindu District of Chengdu City for example,the positive and negative functions of college suburbanization in suburb urbanization have been analyzed through complex indexes of urbanization evaluation.Furthermore,it has analyzed positive functions on urbanization of suburb population,suburb economy,suburb residents' life style and values,as well as negative functions on government's administration and land resources' use.On this basis,countermeasures to transform negative effects into positive effects have been proposed.
基金supported by the General Research Fund[grant numbers 15602619,15603920,14605920,and 14611621]the Collaborative Research Fund[grant numbers C5062-21GF and C4023-20GF]from the Hong Kong Research Grants Council+1 种基金the Research Institute for Land and Space of the Hong Kong Polytechnic University[grant number 1-CD81]the Research Committee on Research Sustainability of Major Research Grants Council Funding Schemes of the Chinese University of Hong Kong.
文摘Rapid morphological and socioeconomic changes have accelerated the urbanization process and urban land use transformation in China.Megacities comprise clusters of urban cities and exhibit both newly formed and well-developed urban land use development beyond administrative boundaries.It is necessary to distinguish the changing effects of spatial-varying driving factors on newly formed urban land uses from well-developed built-up areas in megacities.This study proposed a multi-spatial urbanization framework to quantify region-level socioeconomics,cluster-level ecological morphologies,and grid-level urban functional morphologies.A three-level Bayesian hierarchical model was developed to investigate the impacts of multi-spatial driving factors on urban land use transformation in megacities.The study period focused on the urbanization process between 2000 and 2018 in Guangdong-Hong Kong-Macao Greater Bay Area(GBA).Results revealed that compared with well-developed urban built-up land,changing impacts of three-level driving factors in urban land use transformation could be captured based on the proposed Bayesian hierarchical model.The region-level total population was associated with increasing possibilities in forming new residential land than the well-developed ones in 35 districts/counties/cities in GBA.Cluster-level ecological attributes with higher proportion,lower edge density of urban built areas,and lower-degree ecological complexity showed increasing probability on newly formed industrial and public land.Grid-level urban functional factors including public transportation density and shopping/dining distribution exhibited significantly decreasing probability(coefficients:−2.12 to−0.51)on contributing newly formed land uses compared with the well-developed areas,whereas business/industry distribution represented higher(coefficients:0.99 and 0.15)and lower probabilities(coefficient:−0.22)of forming industrial/public land and residential land separately.This research shows a new attempt to distinguish multi-spatial morphological and socioeconomic effects in urban land use transformation in megacities.
文摘Driven by the rapid development of urbanization in China,a large amount of inefficient land has been generated,and cities need to transform their extensive development methods.To achieve efficient urban development,the relevant departments implement urban renewal actions,and promote sustainable urban development.On the basis of analyzing the concept of urban renewal action,the history and background of urban renewal policies are analyzed,and different levels of policy guidance and priorities are sorted out.Several thoughts are put forward on urban renewal action,aiming to create a beautiful and comfortable urban space.It is hoped that this will have certain guiding significance for urban renewal in China.
基金National Natural Science Foundation of ChinaNo.41630644。
文摘The coordinated development of urban and rural territorial systems has long been a scientific issue of concern in geography and socioeconomic development in China.Based on Territorial Function Theory,this paper establishes a theoretical framework to support the coordinated development of urban and rural territorial systems,analyzes the trend of functional evolution,discusses the impact of efficient allocation and orderly element flow on system equivalence development,and puts forward approaches and policy suggestions for equilibrium development in the future.The main conclusions are as follows:(1)The evolution of urban and rural territorial functions has experienced four stages:rural to rural,rural to urban transition,rural to urban,and urban to urban.In this process,territorial functions have been developed to be hierarchical and advanced.(2)Functional evolution enables urban and rural comparative advantages to be transformed from value difference to value equivalence.Increasing the flow intensity and reconstructing the flow space have become the necessary conditions for the coordination of development.(3)Land is the most important resource in China,and land system reform is the key to achieving equivalence development of urban and rural territorial systems,thereby determining the future equilibrium development of the two systems.
文摘Quantifying the degree of urban function mix has great signifi cance to both urban planning practices and studies. This paper, fi rst of all, based on the data of points of interest(POIs), analyzes the spatial distribution patterns of urban functions in Beijing. Then according to the taxi GPS data with the origin and destination points(taxi-ODs), we identify the spatial and temporal pattern of the degree of urban function mix in Beijing. Finally, based on the information entropy model of the POIs and taxi-ODs, we establish a spatial entropy and a temporal entropy to quantitatively assess the degree of urban function mix, confirming by virtue of correlation analysis and regression analysis that the spatial entropy of POIs is closely associated with the temporal entropy of taxi-ODs, which proves that it is reasonable to assess the degree of urban function mix via these two entropies. As a result, the degree of urban function mix in Beijing is characterized by slowly decreasing from its core area along the 3rd and 4th Ring Roads to its periphery. In detail, there is the highest degree of urban function mix in Beijing's traditional core areas, including Zhongguancun, CBD(Central Business District), the Old Dongcheng District, the Old Xicheng District, and the area within the 2nd Ring Road; a higher degree in Wangjing area; and a low degree in Tiantongyuan and Huilongguan communities. The analytical results have initially achieved a more accurate identifi cation and quantitative evaluation on the degree of urban function mix, and can be taken as a supporting tool to analyze the comprehensiveness of urban functions.
文摘Since the 17th National Congress of the Communist Party of China, ecological civilization has been the key construction goal in China, which has a profound impact on the process of urbanization. In recent years, with the rapid development of urbanization and unreasonable land development and utilization, the ecological environment has deteriorated sharply, and the stability of ecological environment has always been a difficult problem in the process of regional development. The spatial division of urban ecological function can be divided into different types of spatial utilization according to the fragile state of ecological environment, which not only guarantees urban construction but also maintains the ecological environment health, and has great economic benefits and ecological value in formulating regional development strategies and ecological protection. In this paper, from four perspectives of “land, water, human and forest”, eight factors affecting ecological sensitivity were selected, and GIS spatial superposition method was used to conduct qualitative and quantitative analysis on the ecological sensitivity of Baoji City, and the evaluation results of single factor ecological sensitivity and comprehensive ecological sensitivity were obtained. The areas with different ecological sensitivity are divided into extremely sensitive areas, highly sensitive areas, moderately sensitive areas, slightly sensitive areas and non-sensitive areas. The research shows that the proportion of extreme, high, moderate, mild and insensitive areas in Baoji City is 7.32%, 10.57%, 22.25%, 42.91% and 16.95% respectively. Finally, the areas with different sensitivity grades are identified as three types of urban ecological function areas: ecological conservation area, ecological coordinated moderate utilization area and ecological suitable construction area, so as to provide scientific theoretical basis for urban construction and land use optimization in Baoji City.
基金National Nature Science Foundation of China (Grant No. 40571056).
文摘Rapid urbanization in Beijing stimulates the urban land expansion and diminishes available agricultural land. Monofunctional agricultural land use can not meet the demand of the devel- opment of the multifunctional agriculture and urbanization any more, so multifunctional agricultural land use is going to be promoted in the city. This article proposes the evolvement of the land use change from 1992 to 2004 and discusses some evolvement views.
文摘This methodological investigation deals with measurement and valuation of ecological service functions for urban green space. Social, economic and ecological dimensions for such types of function were analyzed and a concept “integrated ecological service functions” (IESF) was put forward for evaluation. Based upon this conceptual approach, an index system for measuring IESF for urban green space was established. With a methodological integration of fuzzy mathematics, decision making analysis and Delphi method, an AHP fuzzy evaluation techniques for IESF for urban green space, called AFIFUG method, was developed. Such a method has been directly applied to the land use strategic planning of Tianjin out ring green belt(TOGB), and its analysis results have been successfully put into operation.
文摘From the perspective of balancing urban and rural development,this article researches the factors influencing the consumption level of rural residents in China.I select the relevant data concerning per capita net income of rural households and annual per capita consumer spending of rural residents for living in the period 1985-2008,establish the regression model of per capita net income of rural households and per capita consumer spending of rural residents for living,and conduct regression analysis and error correction model test using the measurement software.The analysis results show that there is not only long-term equilibrium relationship between rural residents' current consumption and rural residents' current income,between rural residents' consumption in lag period 1 and rural residents' income in lag period 1,but also short-term equilibrium relationship;current income is the main reason for determining the current consumption).Corresponding proposals are put forward to promote the level of rural consumption in China as follows:propel agricultural modernization;actively develop specialized cooperative organizations of rural residents;improve rural land transfer mechanism;promote the level of public services in rural areas;accelerate the transfer of rural surplus labor.
