In Wuhu,urban renewal has not only transformed the development process,but improved people’s lives.DURING the 14th Five-Year Plan period(2021-2025),urban renewal has served as a crucial measure to promote high-qualit...In Wuhu,urban renewal has not only transformed the development process,but improved people’s lives.DURING the 14th Five-Year Plan period(2021-2025),urban renewal has served as a crucial measure to promote high-quality urban development and continuously meet people’s growing aspirations for a better life.Wuhu,in central China’s Anhui Province,has consistently enhanced its urban functions and services to build a modern,people-oriented city that is innovative,livable,beautiful,resilient,and smart.展开更多
Large-scale urban land expansion in mountainous and hilly areas(UEMH)has significantly altered the terrain in many Chinese cities,leading to various environmental and urban challenges.Despite its importance,there is l...Large-scale urban land expansion in mountainous and hilly areas(UEMH)has significantly altered the terrain in many Chinese cities,leading to various environmental and urban challenges.Despite its importance,there is limited nation-scale research that reveals the amount and the spatial variations of UEMH-induced terrain alteration.This research integrates the Global Annual Urban Dynamics dataset,the Global Basic Landform Unit dataset,the TanDEM-X DEM Change Map(DCM)dataset,Baidu Points-of-Interest(POI),and other auxiliary datasets to conduct a comprehensive analysis of terrain alteration induced by UEMH in China from 2012 to 2020.The results indicate that the country-wide UEMH-induced terrain alteration reached approximately 13 billion m^(3),which is about 100 times the volume of Hangzhou West Lake,and terrain alteration volume in over 300 counties exceeded 10 million m^(3).The Southwest and Southeast regions,which are ecologically sensitive and critical,feature the greatest alteration in terms of area and volume.The most significant terrain alteration in terms of intensity is observed in the Southwest and Hengduan Mountain Area.Additionally,there are significant spatial variations in the contributions of different urban functional zones to terrain alteration.Our findings indicate that urban land expansion in mountains and hills has significantly altered terrain in some regions of China,necessitating customized urban planning strategies for better managing mountainous urban land expansion and governance policies to address the geological,ecological,and urban development challenges.展开更多
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
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
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
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
Rapidly developing cities are under continuous physical and social changes which make sustainable urban growth concept a matured line of thinking. They are therefore, in need of restructuring to contain these changes....Rapidly developing cities are under continuous physical and social changes which make sustainable urban growth concept a matured line of thinking. They are therefore, in need of restructuring to contain these changes. Likewise, Khartoum is growing rapidly and is subjected to continual transformation. It started in Independence Day （1/1/1956） by 〈3% of Sudan population and reached 16.8% in 2010 while its physical block grew beyond imagination. The objective of this paper is to throw light on Khartoum rapid growth change effects which necessitated implementation of a revolutionary restructuring programme. At first, huge rural influxes were absorbed and later physical distortions were corrected. This included squatter settlements＇ treatment to strengthen urban fabric, reallocation of incompatible urban functions, revitalization of the CBD （central business district） and other urban renewal schemes. Transportation lines were extended to ease people mobility and higher population concentrations were diluted, particularly the filthy slums. Old neighbourhoods, traditional villages, etc. were re-planned and popular physical development was encouraged. The restructuring programme appropriated population distribution, administrative districts, new local markets＇ locations and urban activities＇ distribution. The programme attained social benefits, particularly availing shelter and essential social services. Difficulties from relocation processes were encountered but settlements＇ regularization achieved social justice and sustained urban growth.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
This study establishes a framework to assess greenspace supply-demand disparities related to thermal discomfort from the perspective of population mobility across urban functional zones(UFZs).High-resolution greenspac...This study establishes a framework to assess greenspace supply-demand disparities related to thermal discomfort from the perspective of population mobility across urban functional zones(UFZs).High-resolution greenspace maps and location-based service(LBS)datasets for Nanjing,China,were combined with Spearman correlation analyses and a four-quadrant model to elucidate associations and matching patterns between greenspace exposure and thermal comfort.The findings indicate that population fluctuations affect the availability of actual greenspace,with correlations to thermal discomfort showing significant temporal variations among different UFZs.During morning workday hours,commercial zones have a significantly higher representation in Quadrant Ⅱ(82.26%)compared to non-workdays(70.86%),which is characterized by high population density,low greenspace exposure,and pronounced thermal discomfort.In contrast,residential and public service zones maintain consistently high and stable proportions in Quadrant Ⅰ across all periods.This spatial mismatch is primarily caused by differences in available greenspace quantities and population mobility.Planning adjustments should focus on ensuring sufficient greenspace provision in key areas during peak population mobility periods to mitigate thermal discomfort.Minimizing residents'staying time in thermally uncomfortable zones,implementing time-specific greenspace access,and strategically increasing greenspace coverage are essential for improving the mismatch between greenspace supply and demand.展开更多
Microplastics(MPs;<5 mm)have become one of the most prominent global environmental pollution problems.MPs can spread to high altitudes through atmospheric transport and can be deposited by rainfall or snowfall,pote...Microplastics(MPs;<5 mm)have become one of the most prominent global environmental pollution problems.MPs can spread to high altitudes through atmospheric transport and can be deposited by rainfall or snowfall,potentially threatening the structure and function of natural ecosystems.MPs in terrestrial and aquatic ecosystems alter the growth and functional characteristics of organisms.However,little attention has been given to the possible harm associated with MPs deposited in snow,particularly in the context of global climate warming.MPs collected from surface snow in the Inner Mongolia Plateau,China,were used for quantitative analysis and identification.The results showed that MPs were easily detected,and the related concentration was approximately(68±10)–(199±22)MPsL1 in snow samples.Fibers were the most common morphology,the polymer composition was largely varied,and the abundance and composition of MPs were linked to human activity to a great extent.High-throughput sequencing results showed that the composition and abundance of microorganisms also differed in snow samples from areas with different MP pollution characteristics,indicating a considerable difference in microbial functional diversity.MPs may have an interference effect on the individual growth and functional expression of microorganisms in snow.In addition,the results showed that functional living areas(e.g.,landfills and suburban areas)in cities play an important role in the properties of MPs.For instance,the highest abundance of MPs was found in thermal power plants,whereas the abundance of polymers per sample was significantly lower in the suburban area.The MP contaminants hidden in snow can alter microbial structure and function and are therefore a potential threat to ecosystem health.展开更多
Urban subway station is a key node related to urban social,political,economic and cultural activities.There are some differences in the location,function orientation,land use and flow characteristics of different type...Urban subway station is a key node related to urban social,political,economic and cultural activities.There are some differences in the location,function orientation,land use and flow characteristics of different types of stations in the city.This paper mainly used Tyson’s edge,kernel density analysis,chart analysis and other methods to classify the functional types of 412,393 POI data of 26 stations along Metro he results showed that the spatial distribution of Beijing Metro Line 6 was mainly divided into 3 categories,subway stations were divided into 4 categories.Among them,type A sites were divided into composite and single types,and the distribution characteristics of the 6 types of sites were quite different.Based on the qualitative and quantitative analysis of POI point data,this method can quickly classify and analyze the characteristics of stations along Line 6 in Beijing,which also has theoretical and practical value for the planning of urban subway lines.展开更多
Eco-city development is a healthy process towards sustainable development, within the carrying capacity of local ecosystem through changing production mode, consumption behavior and decision instrument based on ecolog...Eco-city development is a healthy process towards sustainable development, within the carrying capacity of local ecosystem through changing production mode, consumption behavior and decision instrument based on ecological economics and system engineering. The key to its planning is an ecological integration to make trade-off between economic wealth and environmental health, between material and spiritual civilization, between natural and human eco-cybernetics. Integration, demonstration, citizens’ participation and scientists’ and technician’s catalyzing are the key instruments for the implementation of the ecocity plan. "Clean production" and "ecological industry" are key elements in comprehensive development towards an eco-city. Beyond the technical and management questions, how to interlink production, consumption and reduction at the local and regional level, the spatial and urban dimension should be considered in order to perform an integrative urban eco-space.展开更多
In this paper, we analyse the main strategy for the development of Beijing as it was presented by the last Master Plan: “Beijing should be, by the middle of the 21st century an international modern metropolis of the ...In this paper, we analyse the main strategy for the development of Beijing as it was presented by the last Master Plan: “Beijing should be, by the middle of the 21st century an international modern metropolis of the first world rank”. At first, we summarize the current Chinese studies and urban changes that are being carried out in Beijing, both in spatial and function aspects. Further, we underline the necessity to Beijing to become a powerful economically modernized metropolis. We emphasize with three main reasons in order to explain this necessity: the new “socialist economic market” in China, the inter urban competition among Chinese cities, and the comparison with the current metropolises of the first world rank. Finally, after a summary about the internalization process of London, Paris, New York and Tokyo, we present a simplified analysis of the urban internalization process. According to this analysis, we conclude that Beijing must combine two status: a powerful economically modernized metropolis and the Asian Cultural Capital status, so that could project Beijing into the next century as one of the elite metropolis in the world.展开更多
Represents the first attempt to classify all of China’s295 cities in terms of industrial functions,using 1984 data.Within the framework of economic base theory of urban development,three elements are defined as speci...Represents the first attempt to classify all of China’s295 cities in terms of industrial functions,using 1984 data.Within the framework of economic base theory of urban development,three elements are defined as specialized branch,functional intensity and functional scale.The method used here is based on a combination of the three elements.A number of techniques tried made it possible to base the classification on a composite measure,consisting of the Ward’s Error Method of hierarchical cluster analysis and a supplementary application of Nelson measure.The 295 cities have been grouped into three categories with 19 subcategories and 54 functional groups.The distribution of cities in most of the subcategories are displayed on 8 maps.展开更多
As an important urban infrastructure,rail transit not only has transportation function,but also has a close connection and harmonious development with the surrounding urban space.Taking Beijing Metro Line 5 as an exam...As an important urban infrastructure,rail transit not only has transportation function,but also has a close connection and harmonious development with the surrounding urban space.Taking Beijing Metro Line 5 as an example,each station of Beijing Metro Line 5 was analyzed by GIS software and Echarts chart based on POI data.The functions of subway site type were divided into main function,secondary function and no significant function,and various types of sites within the main functional characteristics of urban functions were discussed in details.The paper presents a new method for identifying urban functional features,which can be applied to not only other metro stations in Beijing but also the same type of cities.Moreover,it lays a foundation for the research of rail transit subway stations and their related researches.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
文摘In Wuhu,urban renewal has not only transformed the development process,but improved people’s lives.DURING the 14th Five-Year Plan period(2021-2025),urban renewal has served as a crucial measure to promote high-quality urban development and continuously meet people’s growing aspirations for a better life.Wuhu,in central China’s Anhui Province,has consistently enhanced its urban functions and services to build a modern,people-oriented city that is innovative,livable,beautiful,resilient,and smart.
基金supported by the National Natural Science Foundation of China(Grants No.42322110 and 42271415)。
文摘Large-scale urban land expansion in mountainous and hilly areas(UEMH)has significantly altered the terrain in many Chinese cities,leading to various environmental and urban challenges.Despite its importance,there is limited nation-scale research that reveals the amount and the spatial variations of UEMH-induced terrain alteration.This research integrates the Global Annual Urban Dynamics dataset,the Global Basic Landform Unit dataset,the TanDEM-X DEM Change Map(DCM)dataset,Baidu Points-of-Interest(POI),and other auxiliary datasets to conduct a comprehensive analysis of terrain alteration induced by UEMH in China from 2012 to 2020.The results indicate that the country-wide UEMH-induced terrain alteration reached approximately 13 billion m^(3),which is about 100 times the volume of Hangzhou West Lake,and terrain alteration volume in over 300 counties exceeded 10 million m^(3).The Southwest and Southeast regions,which are ecologically sensitive and critical,feature the greatest alteration in terms of area and volume.The most significant terrain alteration in terms of intensity is observed in the Southwest and Hengduan Mountain Area.Additionally,there are significant spatial variations in the contributions of different urban functional zones to terrain alteration.Our findings indicate that urban land expansion in mountains and hills has significantly altered terrain in some regions of China,necessitating customized urban planning strategies for better managing mountainous urban land expansion and governance policies to address the geological,ecological,and urban development challenges.
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.
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.
文摘Rapidly developing cities are under continuous physical and social changes which make sustainable urban growth concept a matured line of thinking. They are therefore, in need of restructuring to contain these changes. Likewise, Khartoum is growing rapidly and is subjected to continual transformation. It started in Independence Day （1/1/1956） by 〈3% of Sudan population and reached 16.8% in 2010 while its physical block grew beyond imagination. The objective of this paper is to throw light on Khartoum rapid growth change effects which necessitated implementation of a revolutionary restructuring programme. At first, huge rural influxes were absorbed and later physical distortions were corrected. This included squatter settlements＇ treatment to strengthen urban fabric, reallocation of incompatible urban functions, revitalization of the CBD （central business district） and other urban renewal schemes. Transportation lines were extended to ease people mobility and higher population concentrations were diluted, particularly the filthy slums. Old neighbourhoods, traditional villages, etc. were re-planned and popular physical development was encouraged. The restructuring programme appropriated population distribution, administrative districts, new local markets＇ locations and urban activities＇ distribution. The programme attained social benefits, particularly availing shelter and essential social services. Difficulties from relocation processes were encountered but settlements＇ regularization achieved social justice and sustained urban growth.
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 China,No.42371397The Key Laboratory of Lake and Watershed Science for Water Security,No.NKL2023-KP03。
文摘This study establishes a framework to assess greenspace supply-demand disparities related to thermal discomfort from the perspective of population mobility across urban functional zones(UFZs).High-resolution greenspace maps and location-based service(LBS)datasets for Nanjing,China,were combined with Spearman correlation analyses and a four-quadrant model to elucidate associations and matching patterns between greenspace exposure and thermal comfort.The findings indicate that population fluctuations affect the availability of actual greenspace,with correlations to thermal discomfort showing significant temporal variations among different UFZs.During morning workday hours,commercial zones have a significantly higher representation in Quadrant Ⅱ(82.26%)compared to non-workdays(70.86%),which is characterized by high population density,low greenspace exposure,and pronounced thermal discomfort.In contrast,residential and public service zones maintain consistently high and stable proportions in Quadrant Ⅰ across all periods.This spatial mismatch is primarily caused by differences in available greenspace quantities and population mobility.Planning adjustments should focus on ensuring sufficient greenspace provision in key areas during peak population mobility periods to mitigate thermal discomfort.Minimizing residents'staying time in thermally uncomfortable zones,implementing time-specific greenspace access,and strategically increasing greenspace coverage are essential for improving the mismatch between greenspace supply and demand.
基金supported by the funds for the National Natural Science Foundation of China(52070183)the International Cooper ation and Exchange of the National Natural Science Foundation of China(51820105011)the Program of the Youth Innovation Promotion Association of Chinese Academy of Sciences(2019044).
文摘Microplastics(MPs;<5 mm)have become one of the most prominent global environmental pollution problems.MPs can spread to high altitudes through atmospheric transport and can be deposited by rainfall or snowfall,potentially threatening the structure and function of natural ecosystems.MPs in terrestrial and aquatic ecosystems alter the growth and functional characteristics of organisms.However,little attention has been given to the possible harm associated with MPs deposited in snow,particularly in the context of global climate warming.MPs collected from surface snow in the Inner Mongolia Plateau,China,were used for quantitative analysis and identification.The results showed that MPs were easily detected,and the related concentration was approximately(68±10)–(199±22)MPsL1 in snow samples.Fibers were the most common morphology,the polymer composition was largely varied,and the abundance and composition of MPs were linked to human activity to a great extent.High-throughput sequencing results showed that the composition and abundance of microorganisms also differed in snow samples from areas with different MP pollution characteristics,indicating a considerable difference in microbial functional diversity.MPs may have an interference effect on the individual growth and functional expression of microorganisms in snow.In addition,the results showed that functional living areas(e.g.,landfills and suburban areas)in cities play an important role in the properties of MPs.For instance,the highest abundance of MPs was found in thermal power plants,whereas the abundance of polymers per sample was significantly lower in the suburban area.The MP contaminants hidden in snow can alter microbial structure and function and are therefore a potential threat to ecosystem health.
基金Beijing Municipal Education Commission Social Science Project(KM202010009002)Beijing Municipal Social Science Foundation(22GLC062)“Young YuYou Talents Training Plan”of North China University of Technology.
文摘Urban subway station is a key node related to urban social,political,economic and cultural activities.There are some differences in the location,function orientation,land use and flow characteristics of different types of stations in the city.This paper mainly used Tyson’s edge,kernel density analysis,chart analysis and other methods to classify the functional types of 412,393 POI data of 26 stations along Metro he results showed that the spatial distribution of Beijing Metro Line 6 was mainly divided into 3 categories,subway stations were divided into 4 categories.Among them,type A sites were divided into composite and single types,and the distribution characteristics of the 6 types of sites were quite different.Based on the qualitative and quantitative analysis of POI point data,this method can quickly classify and analyze the characteristics of stations along Line 6 in Beijing,which also has theoretical and practical value for the planning of urban subway lines.
文摘Eco-city development is a healthy process towards sustainable development, within the carrying capacity of local ecosystem through changing production mode, consumption behavior and decision instrument based on ecological economics and system engineering. The key to its planning is an ecological integration to make trade-off between economic wealth and environmental health, between material and spiritual civilization, between natural and human eco-cybernetics. Integration, demonstration, citizens’ participation and scientists’ and technician’s catalyzing are the key instruments for the implementation of the ecocity plan. "Clean production" and "ecological industry" are key elements in comprehensive development towards an eco-city. Beyond the technical and management questions, how to interlink production, consumption and reduction at the local and regional level, the spatial and urban dimension should be considered in order to perform an integrative urban eco-space.
文摘In this paper, we analyse the main strategy for the development of Beijing as it was presented by the last Master Plan: “Beijing should be, by the middle of the 21st century an international modern metropolis of the first world rank”. At first, we summarize the current Chinese studies and urban changes that are being carried out in Beijing, both in spatial and function aspects. Further, we underline the necessity to Beijing to become a powerful economically modernized metropolis. We emphasize with three main reasons in order to explain this necessity: the new “socialist economic market” in China, the inter urban competition among Chinese cities, and the comparison with the current metropolises of the first world rank. Finally, after a summary about the internalization process of London, Paris, New York and Tokyo, we present a simplified analysis of the urban internalization process. According to this analysis, we conclude that Beijing must combine two status: a powerful economically modernized metropolis and the Asian Cultural Capital status, so that could project Beijing into the next century as one of the elite metropolis in the world.
文摘Represents the first attempt to classify all of China’s295 cities in terms of industrial functions,using 1984 data.Within the framework of economic base theory of urban development,three elements are defined as specialized branch,functional intensity and functional scale.The method used here is based on a combination of the three elements.A number of techniques tried made it possible to base the classification on a composite measure,consisting of the Ward’s Error Method of hierarchical cluster analysis and a supplementary application of Nelson measure.The 295 cities have been grouped into three categories with 19 subcategories and 54 functional groups.The distribution of cities in most of the subcategories are displayed on 8 maps.
基金Sponsored by Beijing Municipal Social Science Foundation“Research on Service Function Renewal of Beijing Subway Station Living Circle Driven by Multiple Big Data”(22GLC062)Beijing Municipal Education Commission Social Science Project(KM202010009002)“Young Yu You Talents Training Plan”of North China University of Technology。
文摘As an important urban infrastructure,rail transit not only has transportation function,but also has a close connection and harmonious development with the surrounding urban space.Taking Beijing Metro Line 5 as an example,each station of Beijing Metro Line 5 was analyzed by GIS software and Echarts chart based on POI data.The functions of subway site type were divided into main function,secondary function and no significant function,and various types of sites within the main functional characteristics of urban functions were discussed in details.The paper presents a new method for identifying urban functional features,which can be applied to not only other metro stations in Beijing but also the same type of cities.Moreover,it lays a foundation for the research of rail transit subway stations and their related researches.
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.
