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
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
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
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
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
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
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
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
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.
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.
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 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.
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.
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 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.