scholarly journals Identifying Urban Functional Areas in China’s Changchun City from Sentinel-2 Images and Social Sensing Data

2021 ◽  
Vol 13 (22) ◽  
pp. 4512
Author(s):  
Shouzhi Chang ◽  
Zongming Wang ◽  
Dehua Mao ◽  
Fusheng Liu ◽  
Lina Lai ◽  
...  
Keyword(s):  
Mobile Phone ◽  
Urban Space ◽  
Central Area ◽  
Urban System ◽  
Identification Accuracy ◽  
Functional Area ◽  
Social Sensing ◽  
Sensing Data ◽  
Changchun City ◽  
Functional Areas

The urban functional area is critical to an understanding of the complex urban system, resource allocation, and management. However, due to urban surveys’ focus on geographic objects and the mixture of urban space, it is difficult to obtain such information. The function of a place is determined by the activities that take place there. This study employed mobile phone signaling data to extract temporal features of human activities through discrete Fourier transform (DFT). Combined with the features extracted from the point of interest (POI) data and Sentinel images, the urban functional areas of Changchun City were identified using a random forest (RF) model. The results indicate that integrating features derived from remote sensing and social sensing data can effectively improve the identification accuracy and that features derived from dynamic mobile phone signaling have a higher identification accuracy than those derived from POI data. The human activity characteristics on weekends are more distinguishable for different functional areas than those on weekdays. The identified urban functional layout of Changchun is consistent with the actual situation. The residential functional area has the highest proportion, accounting for 33.51%, and is mainly distributed in the central area, while the industrial functional area and green-space are distributed around.

scholarly journals Identification of Urban Functional Area by Using Multisource Geographic Data: A Case Study of Zhengzhou, China

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jingzhong Li ◽  
Xiao Xie ◽  
Bingyu Zhao ◽  
Xiao Xiao ◽  
Jingxin Qiao ◽  
...  
Keyword(s):  
Public Awareness ◽  
Central Area ◽  
Central China ◽  
Functional Area ◽  
Accurate Identification ◽  
The Sustainable Development ◽  
Rational Allocation ◽  
Geographic Data ◽  
Thematic Information ◽  
Functional Areas

The rational allocation of functional areas is the foundation for addressing the sustainable development of cities. Efficient and accurate identification methods of urban functional areas are of great significance to the adjustment and testing of urban planning and industrial layout optimization. Firstly, by employing multisource geographic data, an identification method of urban functional areas was developed. A quantitative measurement approach of the urban functional area was then established considering the comprehensive effects of human-land, space-time, and thematic information to present the covering area of ground objects, public awareness, and empirical research. Finally, the Zhengzhou city, which locates in Henan province of central China, was used to test the method. The results show that the developed method is efficient, accurate, and universal and can identify urban functional areas quickly and accurately. We found that the overall distribution of Zhengzhou’s functional areas presents a spatial pattern of single and multimixed coordinated development. The city’s commercial functional areas and commercial-based mixed functional areas are located in the city’s central area. The green square’s function area occupies relatively low and is mainly distributed in the city’s fringe.

scholarly journals Exploring Impact of Spatial Unit on Urban Land Use Mapping with Multisource Data

2020 ◽  
Vol 12 (21) ◽  
pp. 3597
Author(s):  
Xuanyan Dong ◽  
Yue Xu ◽  
Leping Huang ◽  
Zhigang Liu ◽  
Yi Xu ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Urban Land ◽  
Urban Land Use ◽  
Remote Sensing Images ◽  
Social Sensing ◽  
Sensing Data ◽  
Object Based ◽  
Land Use Types ◽  
Functional Areas

The ability to precisely map urban land use types can significantly aid urban planning and urban system understanding. In recent years, remote sensing images and social sensing data have been frequently used for urban land use mapping. However, there still remains a problem: what is the best basic unit for fusing remote sensing images with social sensing data? The aim of this study is to explore the impact of spatial units on urban land use mapping, with remote sensing images and social sensing data of Shenzhen City, China. Three different basic units were first applied to delineate urban land use types, and for each unit, a word dictionary was built by fusing natural–physical features from high spatial resolution (HSR) remote sensing images and the socioeconomic semantic features from point of interest (POI) data. The latent Dirichlet allocation (LDA) algorithm and random forest methods were then applied to map the land use of the Futian district—the core region of Shenzhen. The experiment demonstrates that: (1) No matter what kind of spatial unit, it is beneficial to fuse multisource data to improve the performance. However, when using different spatial units, the importances of features are different. (2) Using block-based spatial units results in the final map looking the best. However, a great challenge of this approach is that the scale is too coarse to handle mixed functional areas. (3) Using grid- and object-based units, the problem of mixed functional areas can be better solved. Additionally, the object-based land use map looks better from our visual interpretation. Accordingly, the results of this study could give other researchers references and advice for future studies.

scholarly journals The Imaginable City

2021 ◽  
Author(s):  
◽  
Yunyun Tian
Keyword(s):  
Urban Space ◽  
Large Scale ◽  
Urban Landscape ◽  
Design Method ◽  
Central Area ◽  
Urban System ◽  
Design Solution ◽  
Self Identity ◽  
Human Needs ◽  
Designed Environment

<p><b>The latter half of the 20th century saw rapid urban development, implemented to meet rapid growth and changing infrastructural needs. Cities around the world became designed homogeneously. In the early decades of the 21st century, the re-inhabitation of the post-industrial city has brought opportunities to bring new ideas to this homogeneity; yet templates and formulas still seem to gain ground: cities are losing their identity, as well as their imaginability. Within this problematic context, New Plymouth Central Area is a representative urban space. New Plymouth District Council has proposed a banally universal design framework, that promises only to continue burying the unique identity of its urban space, rather than liberating it to the imagination. The contemporary discipline still tends to design directly for universal human needs; an approach that ends up suggesting a city’s identity to its citizens, rather than empowering citizens to imagine, and then create, that identity.</b></p> <p>This design-led research proposes that landscape design and urban planning can recover the identity of the New Plymouth Central Area by enhancing its legibility and imaginability. It explores techniques for coordinating mental recognition with visual perceptions, to evoke human imagination of a large-scale urban landscape. It argues that imaginable space can be achieved by creating a mentally identifiable system, with urban patterns, for human physical experimentation and mental recognition to navigate; through agency of this urban system to allow those same dynamics to permeate the history and cultural value of the site; to strengthen the citizen’s recognition of self-identity, which always relates to, and measures itself by, the identity of the land. </p> <p>The outcomes of this research are: an abstract design method that communicates the mental recognition of landscape and its relation to the designed environment; and a physical design solution, testing the abstract method, for a legible and imaginable New Plymouth City.</p>

scholarly journals Data Mining and Knowledge Discovery

2021 ◽  
pp. 797-814
Author(s):  
Chao Zhang ◽  
Jiawei Han
Keyword(s):  
Data Mining ◽  
Urban Space ◽  
Physical World ◽  
Data Mining Techniques ◽  
Social Sensing ◽  
Sensing Data ◽  
Activity Modeling ◽  
Empirical Performance ◽  
Recent Developments ◽  
Urban Activity

AbstractOur physical world is being projected into online cyberspace at an unprecedented rate. People nowadays visit different places and leave behind them million-scale digital traces such as tweets, check-ins, Yelp reviews, and Uber trajectories. Such digital data are a result of social sensing: namely people act as human sensors that probe different places in the physical world and share their activities online. The availability of massive social-sensing data provides a unique opportunity for understanding urban space in a data-driven manner and improving many urban computing applications, ranging from urban planning and traffic scheduling to disaster control and trip planning. In this chapter, we present recent developments in data-mining techniques for urban activity modeling, a fundamental task for extracting useful urban knowledge from social-sensing data. We first describe traditional approaches to urban activity modeling, including pattern discovery methods and statistical models. Then, we present the latest developments in multimodal embedding techniques for this task, which learns vector representations for different modalities to model people's spatiotemporal activities. We study the empirical performance of these methods and demonstrate how data-mining techniques can be successfully applied to social-sensing data to extract actionable knowledge and facilitate downstream applications.

scholarly journals The Imaginable City

2021 ◽  
Author(s):  
◽  
Yunyun Tian
Keyword(s):  
Urban Space ◽  
Large Scale ◽  
Urban Landscape ◽  
Design Method ◽  
Central Area ◽  
Urban System ◽  
Design Solution ◽  
Self Identity ◽  
Human Needs ◽  
Designed Environment

<p><b>The latter half of the 20th century saw rapid urban development, implemented to meet rapid growth and changing infrastructural needs. Cities around the world became designed homogeneously. In the early decades of the 21st century, the re-inhabitation of the post-industrial city has brought opportunities to bring new ideas to this homogeneity; yet templates and formulas still seem to gain ground: cities are losing their identity, as well as their imaginability. Within this problematic context, New Plymouth Central Area is a representative urban space. New Plymouth District Council has proposed a banally universal design framework, that promises only to continue burying the unique identity of its urban space, rather than liberating it to the imagination. The contemporary discipline still tends to design directly for universal human needs; an approach that ends up suggesting a city’s identity to its citizens, rather than empowering citizens to imagine, and then create, that identity.</b></p> <p>This design-led research proposes that landscape design and urban planning can recover the identity of the New Plymouth Central Area by enhancing its legibility and imaginability. It explores techniques for coordinating mental recognition with visual perceptions, to evoke human imagination of a large-scale urban landscape. It argues that imaginable space can be achieved by creating a mentally identifiable system, with urban patterns, for human physical experimentation and mental recognition to navigate; through agency of this urban system to allow those same dynamics to permeate the history and cultural value of the site; to strengthen the citizen’s recognition of self-identity, which always relates to, and measures itself by, the identity of the land. </p> <p>The outcomes of this research are: an abstract design method that communicates the mental recognition of landscape and its relation to the designed environment; and a physical design solution, testing the abstract method, for a legible and imaginable New Plymouth City.</p>

scholarly journals Research on Spatiotemporal Differentiation and Influence Mechanism of Urban Resilience in China Based on MGWR Model

2021 ◽  
Vol 18 (3) ◽  
pp. 1056
Author(s):  
Yu Chen ◽  
Mengke Zhu ◽  
Qian Zhou ◽  
Yurong Qiao
Keyword(s):  
Spatial Heterogeneity ◽  
Spatial Correlation ◽  
Spatial Data ◽  
Central Area ◽  
Urban System ◽  
Entropy Method ◽  
Driving Factors ◽  
Spatial Data Analysis ◽  
Eastern Region ◽  
Urban Resilience

Urban resilience in the context of COVID-19 epidemic refers to the ability of an urban system to resist, absorb, adapt and recover from danger in time to hedge its impact when confronted with external shocks such as epidemic, which is also a capability that must be strengthened for urban development in the context of normal epidemic. Based on the multi-dimensional perspective, entropy method and exploratory spatial data analysis (ESDA) are used to analyze the spatiotemporal evolution characteristics of urban resilience of 281 cities of China from 2011 to 2018, and MGWR model is used to discuss the driving factors affecting the development of urban resilience. It is found that: (1) The urban resilience and sub-resilience show a continuous decline in time, with no obvious sign of convergence, while the spatial agglomeration effect shows an increasing trend year by year. (2) The spatial heterogeneity of urban resilience is significant, with obvious distribution characteristics of “high in east and low in west”. Urban resilience in the east, the central and the west are quite different in terms of development structure and spatial correlation. The eastern region is dominated by the “three-core driving mode”, and the urban resilience shows a significant positive spatial correlation; the central area is a “rectangular structure”, which is also spatially positively correlated; The western region is a “pyramid structure” with significant negative spatial correlation. (3) The spatial heterogeneity of the driving factors is significant, and they have different impact scales on the urban resilience development. The market capacity is the largest impact intensity, while the infrastructure investment is the least impact intensity. On this basis, this paper explores the ways to improve urban resilience in China from different aspects, such as market, technology, finance and government.

Mobile Phone Data Based Urban Functional Area Land Use Classification Algorithm

CICTP 2017 ◽  
2018 ◽  
Author(s):  
Jiyuan Tan ◽  
Luxi Dong ◽  
Yanwei Wang ◽  
Yibin Huang ◽  
Li Li ◽  
...  
Keyword(s):  
Land Use ◽  
Mobile Phone ◽  
Classification Algorithm ◽  
Mobile Phone Data ◽  
Land Use Classification ◽  
Functional Area

scholarly journals Commercial services and urban space reconversion in Romania (1990–2017)

2020 ◽  
Vol 60 (1) ◽  
Author(s):  
Radu Săgeată
Keyword(s):  
Urban Space ◽  
Urban System ◽  
Living Standard ◽  
Iron Curtain ◽  
Global Culture ◽  
Large Cities ◽  
Social Segregation ◽  
Specialist Services ◽  
Made In

Concentrating incomes in large cities has encouraged the development of specialist services and the opening of big commercial units. The downfall of ideological barriers east of the former Iron Curtain made global culture combine with endemic sub-cultures, influenced by the living standard. The only limitation of this process appears to be social segregation which restricts demand and creates preferential segments of users. In Romania, financial segregation is directly reflected in the commercial investment made in Bucharest and in the large cities, mostly in the centre and western part of the country. The paper analyses the correlation of financial and commercial services, as well as their location and dispersion strategies at the level of the Romanian urban system.

Identification and quantification of urban space in India: Defining urban macro-structures

Urban Studies ◽  
2018 ◽  
Vol 56 (10) ◽  
pp. 1988-2004 ◽  
Author(s):  
Joan Perez ◽  
Giovanni Fusco ◽  
François Moriconi-Ebrard
Keyword(s):  
Spatial Analysis ◽  
Urban Space ◽  
Urban Sprawl ◽  
Developing Economies ◽  
Urban Structures ◽  
Urban Rural ◽  
Functional Areas ◽  
Over Time ◽  
Identification And Quantification

Urban–rural differences seem particularly pronounced in India, especially when based on the official figures provided by the Census of India, which are heavily dependent on the administrative status of settlements. India, one of the world’s most dynamic and populous countries, still possesses an official urbanisation rate lagging well behind other developing economies. To investigate the extent of Indian urbanisation, this article develops a multi-step methodology using indicators specifically conceived for identifying urban structures in India. In this article, an emphasis is given to the conception and to the spatial analysis of two indicators: metropolitan ranking and meta-agglomerations. A method combining these indicators then allows identifying urban macro-structures acting as a larger organising framework in the regional space. Our results show a multitude of different functional areas that have developed specific urban morphologies over time. Some are particularly marked by high values of urban macrocephaly, small settlements taking the shape of nebulae, urban sprawl, etc.

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