Identifying Region-Wide Functions Using Urban Taxicab Trajectories

Along with the rapid development of China’s economy as well as the continuing urbanization, the internal spatial and functional structures of cities within this country are also gradually changing and restructuring. The study of functional region identification of a city is of great significance to the city’s functional cognition, spatial planning, economic development, human livability, and so forth. Backed by the emerging urban Big Data, and taking the traffic community as the smallest research unit, a method is proposed to identify urban functional regions by combining floating car track data with point of interest (POI) data recorded on an electronic map. It provides a new perspective for the study of urban functional region identification. Firstly, the main functional regions of the city studied are identified through clustering analysis according to the passenger’s spatial-temporal travel characteristics derived from the floating car data. Secondly, the fine-grained identification of the functional region attributes of the traffic communities is achieved using the label information from POI data. Finally, the AND-OR operation is performed on the recognition results derived by the clustering algorithm and the Delphi method, to obtain the identification of urban functional regions. This approach is verified by applying it to the main urban zone within Chengdu’s Third Ring Road. The results show that: (1) There are fewer single functional regions and more mixed functional regions in the main urban zone of Chengdu, and the distribution of the functional regions are roughly concentric centering in the city center. (2) Using the traffic community as a research unit, combined with dynamic human activity trajectory data and static urban interest point data, complex urban functional regions can be effectively identified.

Digital technologies have recently become more advanced, allowing for the development of social networking sites and applications. Despite these advancements, phone calls and text messages still make up the largest proportion of mobile data usage. It is possible to study human communication behaviors and mobility patterns using the useful information that mobile phone data provide. Specifically, the digital traces left by the large number of mobile devices provide important information that facilitates a deeper understanding of human behavior and mobility configurations for researchers in various fields, such as criminology, urban sensing, transportation planning, and healthcare. Mobile phone data record significant spatiotemporal (i.e., geospatial and time-related data) and communication (i.e., call) information. These can be used to achieve different research objectives and form the basis of various practical applications, including human mobility models based on spatiotemporal interactions, real-time identification of criminal activities, inference of friendship interactions, and density distribution estimation. The present research primarily reviews studies that have employed mobile phone data to investigate, assess, and predict human communication and mobility patterns in the context of crime prevention. These investigations have sought, for example, to detect suspicious activities, identify criminal networks, and predict crime, as well as understand human communication and mobility patterns in urban sensing applications. To achieve this, a systematic literature review was conducted on crime research studies that were published between 2014 and 2022 and listed in eight electronic databases. In this review, we evaluated the most advanced methods and techniques used in recent criminology applications based on mobile phone data and the benefits of using this information to predict crime and detect suspected criminals. The results of this literature review contribute to improving the existing understanding of where and how populations live and socialize and how to classify individuals based on their mobility patterns. The results show extraordinary growth in studies that utilized mobile phone data to study human mobility and movement patterns compared to studies that used the data to infer communication behaviors. This observation can be attributed to privacy concerns related to acquiring call detail records (CDRs). Additionally, most of the studies used census and survey data for data validation. The results show that social network analysis tools and techniques have been widely employed to detect criminal networks and urban communities. In addition, correlation analysis has been used to investigate spatial–temporal patterns of crime, and ambient population measures have a significant impact on crime rates.

Ecosystem services are vital for humans in urban regions. However, urban development poses a great risk for the ability of ecosystems to provide these services. In this paper we first address the most important ecosystem services in functional urban regions in Finland. Well accessible and good quality recreational ecosystem services, for example, provided by urban nature, are an important part of a high-quality living environment and important for public health. Vegetation of urban regions can have a role in carbon dioxide sequestration and thus in climate change mitigation. For instance, estimates of carbon sinks can be compared to total CO2 emissions of an urban region, and the municipality can aim at both increasing carbon sinks and decreasing CO2 emissions with proper land-use planning. Large and contiguous core nature areas, smaller green areas and ecological connections between them are the essence of regional ecological networks and are essential for maintaining interconnected habitats for species and thus biological diversity. Thus, both local and regional level ecological networks are vital for maintaining ecosystem services in urban regions. The impacts of climate change coupled with land-use and land cover change will bring serious challenges for maintaining ecosystem services in urban areas. Although not yet widely used in planning practices, the ecosystem services approach can provide an opportunity for land-use planning to develop ecologically sustainable urban regions. Currently, information on ecosystem services of urban regions is lacking and there is a need to improve the knowledge base for land-use planning.

Re-evaluating polycentric urban structure: A functional linkage perspective

BackgroundHuman mobility behaviour modelling plays an essential role in the understanding and control of the spread of contagious diseases by limiting the contact among individuals, predicting the spatio-temporal evolution of an epidemic and inferring migration patterns. It informs programmatic and policy decisions for effective and efficient intervention. The objective of this research is to assess the human mobility pattern and analyse its implication for malaria disease epidemiology.MethodsIn this study, human mobility patterns in Benishangul-Gumuz and Gambella regions in Western Ethiopia were explored based on a cellular network mobility parameter (e.g., handover rate) via real world data. Anonymized data were retrieved for mobile active users with mobility related information. The data came from anonymous traffic records collected from all the study areas. For each cell, the necessary mobility parameter data per hour, week and month were collected. A scale factor was computed to change the mobility parameter value to the human mobility pattern. Finally, the relative human mobility probability for each scenario was estimated. MapInfo and Matlab softwares were used for visualization and analysis purposes. Hourly travel patterns in the study settings were compared with hourly malaria mosquito vector feeding behaviour.ResultsHeterogeneous human movement patterns were observed in the two regions with some areas showing typically high human mobility. Furthermore, the number of people entering into the two study regions was high during the highest malaria transmission season. Two peaks of hourly human movement, 8:00 to 9:00 and 16:00 to 18:00, emerged in Benishangul-Gumuz region while 8:00 to 10:00 and 16:00 to 18:00 were the peak hourly human mobility time periods in Gambella region. The high human movement in the night especially before midnight in the two regions may increase the risk of getting mosquito bite particularly by early biters depending on malaria linked human behaviour of the population.ConclusionsHigh human mobility was observed both within and outside the two regions. The population influx and efflux in these two regions is considerably high. This may specifically challenge the transition from malaria control to elimination. The daily mobility pattern is worth considering in the context of malaria transmission. In line with this malaria related behavioural patterns of humans need to be properly addressed.

A Nemzeti Innovációs Hivatal által támogatott kutatás keretében 2009-től kezdődően az MTA RKK Békéscsabai Osztálya és a Településkutató Osztály (Budapest) munkatársai komplex vizsgálatot indítottak a határon átnyúló várostérségek témakörében.A kutatás főbb csomópontjai a következők voltak:a városrégió megjelenése az európai és hazai területi kutatásokban és politikákban; a városrégiók lehatárolásának módszertani kérdései, figyelembe véve, hogy az eredményeket a felsőoktatásban is szeretnénk alkalmazni; terepi felmérésekkel feltárni a magyar határon átnyúló várostérségek kialakulásának, fejlődésének mozgatórugóit, szakaszait, a határok átalakulásának fázisait. A tanulmányban szereplő Gyulán – az említett terepmunka mellett – elemeztük a város fejlesztési dokumentumait, értékeltük a határ menti együttműködési forrásért benyújtott pályázatokat, áttekintettük a megvalósult fejlesztésekhez kapcsolódó korábbi kérdőívezések eredményeit és a helyi sajtót, továbbá strukturált interjúkat készítettünk a kulcsszereplőkkel. (Helyben 45, kontrollként pedig a romániai oldalon – zömmel Nagyváradon és Aradon – 25 interjút vettünk fel.)A kutatás során tapasztalt térfolyamatok erős egyoldalúságot mutattak Gyula város, illetve a román oldalon elterülő községek viszonylatában. A magyar oldalról történő átmozgás döntően nem a határ közvetlen közelében fekvő kistelepülésekre irányul (kivéve talán Nagyszalontát), hanem erősebben a határhoz közeli partiumi nagyvárosokba – elsődlegesen Nagyváradra és Aradra –, illetve Erdély belső, magyarlakta területei felé. Ezzel szemben, a román határtérségből érkező mozgások egyik meghatározó céltelepülésévé Gyula (és részben Békéscsaba) vált az elmúlt két évtized során. Ennek oka a város megerősödő szolgáltatószerepkörében rejlik (pozitív tényezők), illetve a határ román oldalán a meghatározó térszervező centrumok hiányának, nagy távolságának, nehézkes elérhetőségének tudható be (negatív tényezők).A gazdasági fejlődés a rendszerváltást követően Romániában – még erőteljesebben, mint Magyarországon – a nagyvárosokra és közvetlen környezetükre koncentrálódott, miközben a rurális terekben stagnálás volt megfigyelhető, vagy a korábbi struktúrák leépülése zajlott. E kontextusban, a lokális szintre koncentrálva, Gyula relatív előnye még nőtt is a határ túloldalával összevetve (amit a 2008-ban kirobbant gazdasági válság tartósított). A kulcsszereplőknek a tanulmányban összesített reakciói jelzik, hogy a város képes a határ menti fekvésből, létből előnyt kovácsolni, és azt saját hosszú távú stratégiái elemévé tenni.Gyula és a határ túloldalán fekvő hajdani vonzásterület együttműködésének sajátos eleme, hogy a nemzetiségi arányok alakulása kevéssé zavarja, sokkal gyakoribbak a magyar–román közös akciók, mint a magyar–magyar vagy a román–román kapcsolatok. Éppen erre alapozva kockáztathatjuk meg a feltételezést, hogy a város határon átnyúló szerepkörei hosszabb távon is fennmaradnak sőt erősödhetnek, nem függetlenül a nemzeti szintű és a lokális politikai folyamatok alakulásától.

Mining people's semantic trajectory behaviours from geotagged photographs

The quality of life for people in urban regions can be improved by predicting urban human mobility and adjusting urban planning accordingly. In this study, we compared several possible variables to verify whether a gravity model (a human mobility prediction model borrowed from Newtonian mechanics) worked as well in inner-city regions as it did in intra-city regions. We reviewed the resident population, the number of employees, and the number of SNS posts as variables for generating mass values for an urban traffic gravity model. We also compared the straight-line distance, travel distance, and the impact of time as possible distance values. We defined the functions of urban regions on the basis of public records and SNS data to reflect the diverse social factors in urban regions. In this process, we conducted a dimension reduction method for the public record data and used a machine learning-based clustering algorithm for the SNS data. In doing so, we found that functional distance could be defined as the Euclidean distance between social function vectors in urban regions. Finally, we examined whether the functional distance was a variable that had a significant impact on urban human mobility.

As the capital of China, Beijing has experienced extensive urbanization in the past two decades. To explore the effect of urbanization on plant diversity, we investigated the vascular plant diversity of the whole Beijing Municipality in three different functional (urban, suburban and exurban) regions. For its geo-diversity, Beijing has a rather abundant vascular plant diversity (2,276 species), including 207 species of conservation concern such as endemic, threatened and protected species. The exurban region had not only the highest species diversity (1,998 species), but also the most species of conservation concern (194 species). Urban region possessed the maximum alien species in terms of both absolute number and proportional representation, while the suburban region had the least species diversity (1,026 species). Some problems, such as wetland shrink and biological invasions, were common in the whole Beijing Municipality. However, primary threats to biodiversity differed in the three functional regions. The urban and suburban regions mainly suffered from habitat loss and fragmentation due to urban sprawl, while the exurban region faced serious ecosystem degradation from increasing disturbance from both local and urban people. Based on our investigation, we put forward conservation strategies for the three regions: improving the structure and ecological function of green spaces in urban region, preserving as much remnant natural habitats in the suburban region, and restricting the rural tourism and establishing a biosphere reserve in the exurban region. In addition, improving public education and orientating that more to social aspects of conservation practice is strongly recommended.

As cities grew beyond their administrative borders, the demand for metropolitan governance appeared. The last 50 years proved that there is no one, universal model of metropolitan governance as urban regions are very different all around the world. However, it seems quite obvious that if metropoles are to be the forefront of development, they need to provide a widely defined cohesion within their subordinate territories. Metropolitan political cohesion may be defined as a collaborative public governance which offers tailored managerial solutions for enhancing development based on the subsidiarity principle and the place‐based approach. Drawing on the lessons from major cities in North America and Europe: Copenhagen, Rotterdam, Stockholm, Hannover, London, Wrocław and Toronto the paper intends to dive into a few, selected cases of metropolitan government and the causes behind their failure and reappearance. How have various governments met the cardinal question of metropoles: to provide a resilient match between the functional urban region and the administrative structure? The answer to this question is not straightforward. Metropolitan authorities all over the world manage exceptionally complex systems, where the diversity of actors, complexity of relations and interdependences across an extended, fragmented and dynamic metropolitan region restrain governability. However some general trends in metropolitan governance may be outlined, regarding the recent history, main types of governance and legitimacy of metropolitan administration.

Classifying urban functional regions by integrating buildings and points-of-interest using a stacking ensemble method

The research objectives are exploring characteristics of human mobility patterns, subsequently modelling them mathematically depending on inter-event time ∆t and traveled distances ∆rparameters using CDRs (Call Detailed Records). The observations are obtained from Armada festival in France. Understanding, modelling and simulating human mobility among urban regions is excitement approach, due to itsimportance in rescue situations for various events either indoor events like evacuation of buildings or outdoor ones like public assemblies,community evacuation in casesemerged during emergency situations, moreover serves urban planning and smart cities. The results of numerical simulation are consistent withpreviousinvestigations findings in that real systems patterns are almost follow an exponential distribution.Further experimentations could classify mobility patterns into major classes (work or off) days, also radius of gyration could be considered as influential parameter in modelling human mobility, additionally city rhythm could be extracted by modelling mobility speed of individuals.

With the wide adoption of multi-community structure in many popular online platforms, human mobility across online communities has drawn increasing attention from both academia and industry. In this work, we study the statistical patterns that characterize human movements in cyberspace. Inspired by previous work on human mobility in physical space, we decompose human online activities into return and exploration - two complementary types of movements. We then study how people perform these two movements, respectively. We first propose a preferential return model that uncovers the preferential properties of people returning to multiple online communities. Interestingly, this model echos the previous findings on human mobility in physical space. We then present a preferential exploration model that characterizes exploration movements from a novel online community-group perspective. Our experiments quantitatively reveal the patterns of people exploring new communities, which share striking similarities with online return movements in terms of underlying principles. By combining the mechanisms of both return and exploration together, we are able to obtain an overall model that characterizes human mobility patterns in cyberspace at the individual level. We further investigate human online activities using our models, and discover valuable insights on the mobility patterns across online communities. Our models explain the empirically observed human online movement trajectories remarkably well, and more importantly, sheds better light on the understanding of human cyberspace dynamics.

The frequency and intensity of natural disasters has significantly increased over the past decades and this trend is predicted to continue. Facing these possible and unexpected disasters, understanding and simulating of human emergency mobility following disasters will becomethe critical issue for planning effective humanitarian relief, disaster management, and long-term societal reconstruction. However, due to the uniquenessof various disasters and the unavailability of reliable and large scale human mobility data, such kind of research is very difficult to be performed. Hence, in this paper,we collect big and heterogeneous data (e.g. 1.6 million users' GPS records in three years, 17520 times of Japan earthquake data in four years, news reporting data, transportation network data and etc.) to capture and analyze human emergency mobility following different disasters. By mining these big data, we aim to understand what basic laws govern human mobility following disasters, and develop a general model of human emergency mobility for generating and simulating large amount of human emergency movements. The experimental results and validations demonstrate the efficiency of our simulation model, and suggest that human mobility following disasters may be significantly morepredictable and can be easier simulated than previously thought.

城市生态环境问题已上升到生态安全的层面。以人类生存安全和理想人居环境为目标,基于空间数据和统计资料,利用景观安全格局原理和地理信息系统空间分析方法,构建了包含基本保障格局-缓冲格局-最优格局3个级别的水安全格局、地质灾害安全格局、大气安全格局、生物保护安全格局和农田安全格局,叠加得到高明区综合生态安全格局,在此基础上提出了高明区建设用地扩展最优方案和生态功能分区。结果显示,并非生态安全格局水平越高,城乡发展模式越优,缓冲生态安全格局下的高明区建设用地扩展模式,最可能实现生态安全保护与城镇扩展的和谐发展。综合生态安全格局明确了区域的生态环境敏感区和生态服务功能重要区,为区域生态功能分区提供了新的思路。;High intensity of human activities and inappropriate land-use modes bring an enormous pressure on the susceptible urban ecosystem. Recently, urban ecological and environmental problems have risen to the urban ecological security level in China, especially in economic-developed regions, such as the Changjiang Delta regions and Pearl River Delta regions. So, construction of a good regional ecological security pattern has become an effective means to protect the urban and rural ecological security, to create an optimum urban development mode for such regions and to control the rapid and disordered urban expansion. Aiming to protect the subsistence security of human beings and create an ideal human settlement, we firstly indentified the key points (sources) and ecological processes (landscape-resistance surfaces) for the regional ecological security pattern using the landscape security pattern theory and GIS spatial analysis method on the basis of the terrain, land-use and statistical data. Then, we built five ecological security patterns (the water, geological disasters, air, the biology and the farmland safety pattern), which contain three-level security patterns such as the Basic protection ecological security, the Buffer ecological security and the Optimum ecological security pattern for each element. Next, we overlaid the five ecological security patterns and developed a comprehensive three-level ecological security patterns for Gaoming district of Foshan City. Furthermore, we simulated four urban expansion patterns separately under the Inertial urban development pattern and the three-level ecological security patterns. Results showed that the urban regions always spread along the road and the original urban regions randomly. Open spaces, such as the farmlands and woodlands, were always firstly occupied due to the disordered urban expansion under the inertial development pattern. So the ecosystem security under the Inertial urban development pattern can not be basely protected. While under the Basic, the Buffer and the Optimum ecological security patterns, the integrity and connectivity of the whole ecological system can be progressively improved and the connectivity among towns will be progressively reduced. Integrating from different simulation results, the urban development pattern of Gaoming under Buffer ecological security pattern was the best one to protect the ecological safety and meet the needs of urban expansion simultaneously. It indicated that higher level of ecological security pattern did not mean a more optimum urban and rural development model. On the basis of the Buffer ecological security pattern simulation, we then divided the region of Gaoming into three ecological zones (the ecological zone with low mountains and hills, the eastern plains ecological zone along the Xijiang River, and the tableland-valley agriculture and forestry ecological zone). We further subdivided the three ecological zones into 12 sub-ecological zones and 12 ecological function zones using the hierarchical classification method. Then, the three-level ecological function zone patterns (ecological zones, ecological sub-zones and ecological function zones) of Gaoming were finally developed. It can be clearly seen that the comprehensive ecological security pattern of Gaoming clarified the most sensitive area of the ecology and environment and the most important regions of the ecological functions. Hence, the comprehensive ecological security pattern provided a new method for regional ecological function zoning.