Urban Trajectories Research Articles

In the interstices of ubiquity: respatialising Bogotá through black relational territories

ABSTRACT Through a narrativization that connects heterogeneous and often undetected social lives in Bogotá, Colombia, this article charts the rhizomatic spatial crossings of continuously mobile urban trajectories, the often-unsettled forms of dwelling that they inhabit, and their capacity to make place despite the dismantling of community cohesion and the necropolitical forms of urbanity operated by racial capitalism and coloniality across Latin America – what the article refers to as relational territories, drawing on a rich scholarship on Black Geographies of the everyday and Latin American ‘territorios’. From there, the article explores how paths are being charted out of the racial-colonial maze of Latin America’s city-making, through multiple forms of ordinary resistance/re-existence that create life in the interstices of ongoing necro-politics . Ultimately, the article shows how this pluralistic repertoire mobilized from the urban margins not only points to the difficulties of emplacement for Afro-descendant dwellers in Latin American cities but also to the possibility of respatialising the urban from the decolonial relationality of Améfrica.

Navigating Urban Sustainability: Urban Planning and the Predictive Analysis of Busan’s Green Area Dynamics Using the CA-ANN Model

While numerous studies have employed deep learning and high-resolution remote sensing to predict future land use and land cover (LULC) changes, no study has integrated these predictive tools with the current urban planning context to find a potential issues for sustainability. This study addresses this gap by examining the planning context of Busan Metropolitan City (BMC) and analyzing the paradoxical objectives within the city’s 2040 Master Plan and the subordinate 2030 Busan Master Plan for Parks and Greenbelts. Although the plans advocate for increased green areas to enhance urban sustainability and social wellbeing, they simultaneously support policies that may lead to a reduction in these areas due to urban development. Using the CA-ANN model in the MOLUSCE plugin, a deep learning-based LULC change analysis, we forecast further urban expansion and continued shrinkage of natural green areas. During 1980–2010, Busan Metropolitan City (BMC) underwent high-speed urban expansion, wherein the urbanized areas almost doubled and agricultural lands and green areas, including forests and grassland, reduced considerably. Forecasts for the years 2010–2040 show continued further expansion of urban areas at the expense of areas for agriculture and green areas, including forest and grasslands. Given the master plans, these highlight a critical tension between urban growth and sustainability. Despite the push for more green spaces, the replacement of natural landscapes with artificial parks and green areas may threaten long-term sustainability. In view of these apparently conflicting goals, the urban planning framework for BMC would have to take up increasingly stronger conservation policies and adaptive planning practices that consider environmental preservation on a par with economic development in the light of the planning context and trajectory of urbanization.

Spatio-temporal interplay between ecosystem services and urbanization in the Yangtze River Economic Belt: A new perspective for considering the scarcity effect

The expeditious trajectory of urbanization has profound ramifications on the configuration and functioning of the natural milieu. Given the constrained opulence of natural capital and its indispensable bestowal of ecosystem services in different regions, meticulous contemplation of the relationship between urbanization and the ecosystem service scarcity value (ESSV) while formulating decisions is imperative. This study focuses on the Yangtze River Economic Belt (YREB), where ESSV is quantified by combining the dynamic changes in market supply and demand factors. The influence of supply and demand changes on the ESSV is discussed and analyzed in four scenarios. Subsequently, a multidimensional urbanization comprehensive evaluation index system was established to explore the spatiotemporal interactive response mode between ESSV and urbanization. Our findings manifest a notably augmented ESSV in the YREB from 1990 to 2020, particularly prominent between 2000 and 2010. Moreover, the growth in public goods services outpaced that in private goods services within the same period. Demand-driven scarcity has emerged as the foremost determinant of ESSV. Urbanization levels gradually increased from 1990 to 2020, with a uniform allocation of heightened ESSV and urbanization throughout the region. The urbanization level of YREB, as a whole, exhibited conspicuous spatial heterogeneity, with the downstream region significantly surpassing the middle and upper reaches, and the downstream Yangtze River Delta city cluster and the middle reaches of the Chengdu-Chongqing city cluster notably outpacing that in the surrounding region. The coupling coordination degree (CCD) between the ESSV and urbanization in the YREB develops in a harmonious direction during the study period, accompanied by palpable spatial disparities. The area of unbalanced development gradually decreased, and the area proportion of the coordinated development type of ESSV and urbanization increased continuously. Overall, this study elucidates regional disparities in the reciprocal relationship between the ESSV and urbanization in the YREB, thereby unveiling the extent of incongruity between regional urbanization and the ecosystem. It serves to identify the juncture at which ecological sustainability and urbanization converge harmoniously, thus offering novel insights in achieving comprehensive, high-caliber, and synchronized development in the YREB.

Advancing Urban Resilience Amid Rapid Urbanization: An Integrated Interdisciplinary Approach for Tomorrow’s Climate-Adaptive Smart Cities—A Case Study of Wuhan, China

This research addresses the urgent challenges posed by rapid urbanization and climate change through an integrated interdisciplinary approach combining advanced technologies with rigorous scientific exploration. The comprehensive analysis focused on Wuhan, China, spanning decades of meteorological and land-use data to trace extreme urbanization trajectories and reveal intricate temporal and spatial patterns. Employing the innovative 360° radial Fibonacci geometric growth framework, the study facilitated a meticulous dissection of urban morphology at granular scales, establishing a model that combined fixed and mobile observational techniques to uncover climatic shifts and spatial transformations. Geographic information systems and computational fluid dynamics were pivotal tools used to explore the intricate interplay between urban structures and their environments. These analyses elucidated the nuanced impact of diverse morphosectors on local conditions. Furthermore, genetic algorithms were harnessed to distill meaningful relationships from the extensive data collected, optimizing spatial arrangements to enhance urban resilience and sustainability. This pioneering interdisciplinary approach not only illuminates the complex dynamics of urban ecosystems but also offers transformative insights for designing smarter, more adaptable cities. The findings underscore the critical role of green spaces in mitigating urban heat island effects. This highlights the imperative for sustainable urban planning to address the multifaceted challenges of the 21st century, promoting long-term environmental sustainability and urban health, particularly in the context of tomorrow’s climate-adaptive smart cities.

The rise of urbanism and exchange network: reconstruction of a 4000-year local history of Xinjiang, northwestern China

Urbanization is one of the milestones in the development of human society. Many regions in the southern parts of ‘the old world’ demonstrating an early emergence of agriculture also witnessed the flourishing of some of the earliest cities. Recent, yet still sparse, archaeological evidence appears to indicate a relatively later time for early urbanism in central Eurasia. However, given its vital geographic location and cultural nexus between East and West, more attention should be paid to the sedentary communities and their cities in oases amid the vast droughty desert, particularly in light of the rapidly increasing number of publications on early pastoralism and related communication routes along mountain chains and rivers. This study reveals the trajectory of urbanization and its role in the establishment of an exchange network in Xinjiang’s oasis region via reconstruction of the chronological sequence of the local societal history of the Baiyang River Basin along the southern piedmont of the Eastern Tianshan Mountains. A thorough archaeological investigation and refined radiocarbon dating programme was carried out and coupled with information from historical documentation within a Bayesian statistical framework. The results indicate three pulses of local urbanization during: the Early Iron Age, Tang–Yuan period, and Qing Dynasty, respectively. Combining this with evidence from other parts of Xinjiang, we re-evaluate the role of oasis urbanism in the promotion of trans-regional exchange.

Employing post classification comparison to detect land use cover change patterns and quantify conversions in Abakaliki LGA Nigeria from 2000 to 2022

Rapid urbanization is restructuring landscapes across sub-Saharan Africa. This study employed post-classification comparison of multi-temporal Landsat imagery to characterize land cover changes in Abakaliki Local Government Area, Ebonyi State, Nigeria between 2000 and 2022, addressing the need for empirical baselines to guide sustainable planning. Four classes were considered and images classified with overall accuracy of 95% for the year 2000 and 97% for the year 2022. Notably, 21,000 hectares of vegetation were lost, while built-up and bare land increased by 7500 and 13,700 hectares respectively. Spatial patterns revealed built-up encroachment from vegetation and bare land; this establishes the first standardized quantification of Abakaliki LGA’s shifting landscape, with results supporting compact development models while conserving ecological services under ongoing transformations. The study makes a significant contribution by establishing an empirical baseline characterizing Nigeria's urbanization trajectory essential for evidence-based stewardship of regional resources and livelihoods in a period of accelerating change.

Progress toward some of sustainable development goals in China's population-shrinking cities

A decrease in population is an emerging challenge in China's urbanization trajectory. This study utilizes data from the Sixth and Seventh Population Censuses to identify Chinese cities experiencing population decline, focusing on prefecture-level cities. It employs 30 indicators relevant to nine Sustainable Development Goals (SDGs) concerning urban areas and populations to evaluate the progress of these shrinking cities in 2010 and 2020. A novel metric, "SDG population elasticity", is introduced to quantify the association between population reduction and SDG indexes. The study employs K-means++ clustering for 130 shrinking cities. The findings reveal that out of the 130 cities, 63 exhibit a downward trend in SDG index scores, predominantly in China's northeast and western regions. The Northeast region has negative SDG population elasticity, indicating a lag in sustainable development compared to that in other areas. Additionally, the research categorizes China's shrinking cities into four groups: cities with strong population elasticity feedback-significantly declining SDGs, cities with weak population elasticity feedback-slightly regressing SDGs, cities with high population loss-negative SDGs in decline, and cities with smart population decline-steady SDGs growth. These findings offer a foundation for crafting bespoke policies in shrinking cities to ensure a balanced approach to sustainable development and monitor advancement toward achieving the SDGs.

Housing Policy, Urbanization, and the Production of Homelessness in Greenland

Visible homelessness is on the rise in Nuuk, Greenland. Since the early 2000s, the number of people staying at the municipal shelter, accessing support programs, and registering as homeless in the community has, by a qualitative estimate grown. Attention has also been given to the growing number of Greenlanders living homeless in Danish cities. However, the literature on Greenlandic homelessness remains sparse, and very little literature conceptualizes homelessness in Greenland within its specific geographical, cultural, or social context. To better understand the emergence of visible homelessness, this article explores the social dimensions of homelessness and asks how homelessness can be understood within the dynamics of urbanization in Greenland. Drawing on four years of participant observation in Nuuk with homelessness outreach organizations, and 20 in-depth interviews with both service providers and men and women experiencing homelessness, and four lived experience focus groups, we find that the emergence of homelessness in Greenland is part and parcel of a trajectory of welfare colonialism, resettlement, and contemporary urbanization. We highlight four specific policy issues: 1) an existing housing stock in Nuuk inappropriate for diverse needs; 2) urbanization in the absence of a national housing or homelessness strategy; 3) a lack of integrated supports and reliance on the non-profit sector; 4) and an increasingly punitive approach to managing the limited housing supply. Stepping back, we argue that the emergence of visible northern homelessness is an important lens through which to understand the dynamics of northern urbanization, social marginalization and exclusion, and the continuation of colonial relations in the era of self-governance.

From Countryside to City: How Land Property Rights Drive Migration in China

China’s remarkable economic surge since the 1970s hasn’t erased the pronounced economic disparities across different regions, most notably between rural and urban locales. Rooted in the historical division of land rights and usage stipulated by economic reforms, this urban-rural dichotomy has fostered varied development patterns in infrastructure, primary industries, and foreign trade and investment. At the core of this dichotomy is the contrasting landscape of land property rights—state ownership in urban areas with permissible leaseholds versus collective ownership in rural areas with restrictions on transfer or leasing. This paper investigates how these divergent land property rights regimes have engendered significant migration patterns, predominantly marked by rural to urban migration, in pursuit of better economic prospects. Through a meticulous examination of the Household Responsibility System (HRS) and subsequent agrarian reforms, this paper elucidates how partial property rights and restrictions on land transferability under HRS have had substantial repercussions on domestic migration. The analysis delineates how well-defined and secure property rights, as postulated by prominent theories of property rights, are instrumental in incentivizing migration. When operational, market mechanisms of land property rights enable farmers to lease their lands, thereby fostering migration by reducing the opportunity cost of leaving rural lands. Conversely, in the absence of robust property rights, government mechanisms often lead to forced land acquisitions sans adequate compensation, exacerbating rural-urban income disparities and propelling rural-urban migration. The paper expounds on the multifaceted implications of these migration patterns on economic opportunities, poverty alleviation, and urbanization in China. Additionally, it discusses the ripple effects of rural-urban migration on income disparity and the consequent socioeconomic repercussions. The findings shed light on the complex interrelationship between land property rights and migration, providing a nuanced understanding of China’s urbanization trajectory and its attendant rural-urban disparities. This analysis offers valuable insights for policy formulations aimed at addressing the systemic issues arising from the entrenched land property rights framework, and suggests a pathway towards a more balanced regional economic development and sustainable urbanization in China.

Motorized three-wheelers and their potential for just mobility in Caribbean urban areas

Abstract This paper investigates the role of motorized three-wheelers (MTW) in urban mobility within popular transport, a demand-responsive and unscheduled mode of transportation provided by self-organized small operators frequently operating in grey areas of regulation. Although popular transport is the primary mobility option for millions worldwide, knowledge about its users, operation, and environmental and social impacts remains scarce. This paper sheds light on some of the features and impacts of popular MTW, focusing on two case studies in the Caribbean with different scales and urban trajectories: Puerto Viejo, Costa Rica, and Soledad in Colombia. We explored the relationship between MTW and fragmentation–(in)accessibility–exclusion in these cities, drawing on a framework connecting these concepts in the Latin American and Caribbean context. Using primary data from qualitative and quantitative methods, the paper examines the distribution of inhibitors or enablers of accessibility within the context of unequal, splintered, and fragmented transport and communication infrastructures. Additionally, the environmental impact of MTW in terms of CO2 and PM2.5 emissions is assessed using field data from low-cost sensors. The paper argues that planning for just urban mobility necessitates considering the ecological consequences of various transportation modes and their social consequences and potential for participation and inclusion. The applied methodology introduces low-cost, replicable, and scalable data production and analysis techniques, contributing to future research on sustainable and just mobility in resource-limited urban areas.

Urbanization in France: An Overview of Transformations and Impacts

This paper explores the historical perspectives and contemporary trends of urbanization in France, shedding light on the transformations, challenges, and opportunities that have shaped the country's urban landscape over time. The article begins by tracing the roots of urbanization in the nineteenth century when industrialization spurred rapid urban growth in cities like Paris, Lyon, Marseille, and Bordeaux. The rise of urban infrastructure, including factories, transportation networks, and housing, accommodated the growing urban population.The twentieth century marked a transition in France's urbanization patterns, with post-war reconstruction, suburbanization, and changing societal dynamics playing significant roles. Efforts were made to rebuild and modernize cities after the World Wars, resulting in urban renewal projects and architectural changes. Suburbanization emerged as a trend driven by the desire for improved living conditions outside overcrowded city centers.In recent decades, globalization, technological advancements, and changing lifestyles have influenced urban development patterns in France. Metropolitan areas, particularly the Greater Paris Region, have experienced significant expansion, concentrating economic activities, cultural institutions, and population. However, smaller towns and rural areas have faced population decline and struggles to maintain services and infrastructure.The consequences of urbanization in France have been multifaceted. Cities have become centers of economic innovation, cultural vibrancy, and educational opportunities, attracting talent and fostering creativity. Additionally, urban areas have played a crucial role in France's tourism industry, with cities like Paris and Lyon being major global destinations. However, the rapid growth of cities has presented challenges related to housing affordability, transportation congestion, environmental sustainability, and social inequality.To effectively manage urbanization, policymakers, urban planners, and researchers must understand the driving factors, impacts on local communities, and strategies for sustainable urban development. The article emphasizes the importance of examining demographic shifts, urban planning initiatives, transportation systems, housing dynamics, cultural transformations, and the quest for sustainable development. By analyzing the historical trajectory and current trends of urbanization in France, valuable insights can be gained into the opportunities and challenges faced by the country as it navigates the complexities of a rapidly changing urban landscape.The article concludes by highlighting the need for comprehensive urban planning, sustainable development practices, and inclusive policies to address the challenges posed by urbanization in France. It emphasizes the importance of transportation systems, housing dynamics, affordability, and environmental considerations in creating resilient and livable cities. Additionally, the article suggests that examining specific case studies like Paris, Lyon, and Marseille can provide deeper insights into the unique challenges and successes of urbanization in different cities.

“The Navigators”. Mediterranean Cities and Urban Spaces in the Passage from Late Antiquity to the Early Middle Ages (ca. 600 – ca. 850 CE)

The aim of the paper is to reassess urban trajectories in the Mediterranean during the passage from Late Antiquity to the early Middle Ages. This will be done by focusing on the sites of Amorium, Gortyn, Eleutherna, and Comacchio, places which transcend both the terrestrial and maritime, and the political and military frontiers of the Byzantine empire and the Umayyad Caliphate. Archaeology and material culture will be used – in a comparative perspective – to dissect urban bodies in terms of use of space and function of spatial relationship. This is in order to document the construction of urban models, structures, and infrastructures, which, although often stemming from diverse centralized political and administrative policies, nevertheless accommodated common, cross-cultural developments, including the creation of commercial and artisanal facilities, construction or restoration of religious buildings as foci of settlement, and resilience of local elites as a catalyst of patronage and levels of demand. Particular attention will be given to the role of public spaces as the frame of reference. Indeed, such spaces will be used to show how artistic and architectural displays operated, cultural assumptions could be (re-) discussed, and different types of buildings coexisted. In this respect, the paper will also explore the continuous importance of civic infrastructures and religious buildings as pillars of a yet coherent urban fabric, representatives of the power and wealth of local city-oriented elites, and conveyors of political, artistic, and spatial symbolism, as mutually recognized and experienced by the communities frequenting seventh-to-ninth century eastern Mediterranean urban spaces.

From Books to Airplanes: The Materiality of Global and Urban Entanglements

The articles in this special section employ histories of cities to examine the relationship between human ambitions and the transformation of space, the development of power discrepancies, and unequal access to material and natural resources. They also reveal the relevance of this quintessential human creation to global dynamics on our planet by unveiling the complex and often messy intersection between urban trajectories, local, imperial, or national histories and longue durée global developments. More than a case study, each article delves into the details of the materiality of the urban history they examine to explain how cities exist in the world, or in Richard Harris’s words, “how cities matter” to our shared planetary past and present. In this manner, they answer the call for new conversations about the historical relationship between our urban past and our broader global reality.

Predictive Modeling of Urban Traffic Accident Severity in Türkiye's Centennial: Machine Learning Approaches for Sustainable Cities

With their far-reaching implications for public health, urban development, and societal harmony, traffic accidents remain a global challenge. As the Republic of Türkiye marks its 100th year, predicting traffic accident severity assumes critical significance, aligning with the nation's aspirations for urban renewal and sustainable progress. This research harnesses the capabilities of machine learning (ML) to anticipate accident severities, shedding light on the critical roles of specific driver and vehicle characteristics. In-depth evaluation of various ML techniques—spanning from Random Forest (RF) and Gaussian Naive Bayes to k-NN, CatBoostClassifier, LightGBM, and Decision Trees—was undertaken, drawing on an expansive dataset that mirrors a spectrum of traffic situations. The RF algorithm demonstrated superior predictive prowess, with certain variables such as Engine_Capacity_(CC), Age_of_Driver, Age_of_Vehicle, Day_of_Week, and Vehicle_Type emerging as decisive factors in accident outcomes. Beyond highlighting RF's potential in accident severity prediction, the study emphasizes the significance of critical determinants. These insights offer a roadmap for stakeholders to craft specialized interventions, amplify public awareness efforts, and pioneer infrastructural upgrades, culminating in a vision of enhanced road safety. Furthermore, this investigation charts a course for Türkiye to foster a sustainable urban trajectory through informed urban and traffic planning initiatives.

Digital Inequality In The Archipelago: A Deep Divide Into Balikpapan’s Mobile Banking Ecosystem

Indonesia, archipelagic nation with a growing need for digitalization, has cities such as Balikpapan leading the way in mobile banking as part of this digital transformation. Balikpapan's journey is hindered by a digital divide caused mainly by unequal internet distribution. This research focuses on evaluating the impact of motivation, tangible access, and proficiency in mobile banking on its adoption. The study also examines the influence of demographic variables such as education, age, gender, and location on this phenomenon. The digital divide continues to be a global concern, exhibiting different forms in different regions, as supported by previous research. Balikpapan's urban trajectory offers a unique context for reevaluating this divide. A sample of 347 Balikpapan residents was analyzed using WarpPLS 7.0 software, applying SEM-PLS criteria. The findings reveal a minimal digital divide in the adoption of mobile banking. Disparities in education and location are apparent. This study builds upon the work of van Deursen & van Dijk (2019) and offers new perspectives on the evolving focus from digital access to a more comprehensive development of digital skills. The significance of Balikpapan's narrative lies in its demonstration of the power of intrinsic motivation in driving digital adoption. This highlights the need to reassess strategies aimed at achieving comprehensive digital inclusion.

Handbook on Shrinking cities

It is not our intention here to resuscitate ‘wasteland’ and ‘shrinking’ as epistemological categories but to underline a volume that goes beyond finding new uses for wasteland derived from shrinkage. The contribution chosen for review is one of the last and updated contributions about shrinkage and the management of wasteland which main goal has been the provision of examples based on multi- and trans-disciplinary research and practices for a more sustainable future for shrinking territories. The volume is, in turn, the result of the outcomes of the European-driven program “Reviving shrinking cities – innovative paths and perspectives toward livability for shrinking cities in Europe” and this element add relevance to the field as it is the collective effort of a wider training program for Ph.D. students that hopefully can develop even more their compelling findings.
 The decision to make a reflection on this volume arises from the fact that this meaty 450-page manuscript was organized around research areas and case studies that suddenly had to confront an unexpected and destabilizing factor: the 2020 pandemic. The impact of Covid-19 on urban trajectories has been so significant that it has generated new dynamics worldwide, especially in shrinking realities. For this reason, the contents of “Handbook on Shrinking cities” can serve as a guide for investigating and rethinking ways to intervene in shrinking central, suburban, and rural areas.

Inferring vehicle spacing in urban traffic from trajectory data

This study presents a new method to infer the average two-dimensional (2D) spacing between interacting vehicles in urban traffic from trajectory data. In this context, 2D spacing reflects the amount of road space consumed by pairs of interacting vehicles, and is related to 2D density at the macroscopic level. Due to complex interaction and conflicts in urban traffic, the inherent assumptions in traditional traffic flow models, such as unidirectional flow and homogeneity, are often violated. Such violation challenges direct measurement of urban vehicle spacing. The proposed method addresses this challenge by focusing on the relative movement between interacting vehicles and aggregating the accumulated presence of vehicles in similar scenarios. We apply the method to a large-scale urban trajectory dataset called pNEUMA, and validate the consistency of the method through bootstrapping. By applying the method we obtain a new empirical relation between the average 2D spacing and the relative speeds between interacting vehicles. There are similarities between this empirical relation with the classical Fundamental Diagram of traffic flow in terms of shape and interpretation, and so we term it the “interaction Fundamental Diagram” (iFD). However, there are also key differences. The iFD does not represent steady-state (homogeneous and stationary) longitudinal behaviour; it describes the average amount of road space needed for vehicle interactions at different relative speeds. We believe these iFD relations contribute to understanding vehicle interaction in urban traffic, and can offer new insights for designing safer and more efficient urban intersections.

Understanding Urban Expansion and Its Landscape Responses with Long-Term Landsat Data in Guangzhou, China

Quantifying the spatio-temporal pattern of urban expansion is essential to understanding the ecological consequences of urbanization and supporting optimal urban management strategies. As one of the most developed regions in China, Guangzhou has experienced rapid urban expansion over the past decades. However, little is known about the detailed process of urban expansion across long-term periods. Combining remote sensing data with GIS techniques, we attempted to quantify the spatio-temporal pattern of urban expansion in Guangzhou. We mapped the urban landscape in Guangzhou using Landsat images between 1973 and 2017. The urban land developed and change process was also examined, including urban expansion direction, urban expansion types, and landscape responses to urban expansion. The results showed that the building nearly increased by 90-fold from 1973 to 2017, and over half of the newly developed buildings mainly came from farmland. Edge expansion is the main type of urban growth. The urban trajectory shows that the expansion mainly occurred in the southwest to northeast direction. Urban growth led to radical changes in the urban landscape, leading to sharp decreases in soil and farmland. The results from this study provide key information for future planning to make eco-friendly megacities as well as sustainable development.

Home and Away: Drivers and Perceptions of Migration Among Urban Migrants and Their Rural Families in the Lower Mekong River Basin of Cambodia

Cambodian cities continue to experience major growth, due principally to in-country migration. However, the recent trajectory and historical context of urbanisation differs from other Asian countries and as such are less investigated. Using a framework of interconnected migration factors, this article reports on rural-to-urban migration in five provinces around Phnom Penh—from the perspective of both urban migrants and their rural family members. The work examines the economic, environmental, and sociocultural factors influencing migrants’ current and desired movements, changing livelihood activities, and the permanency of migration choices. While there is evidence to support three major theories of migration—income differentials, environmental change, and social networks—it is argued that none of these alone explains current migration patterns. Explanations of Cambodian migration must account for the powerful attraction of home villages and kin relations, as well as the inseparability of two exogenous factors: the proliferation of microfinance (MFI) and the rise of the garment industry. The results show distinct patterns of migration with implications for adaptation, precarity, and rural livelihoods.

Mobility Inference on Long-Tailed Sparse Trajectory

Analyzing the urban trajectory in cities has become an important topic in data mining. How can we model the human mobility consisting of stay and travel states from the raw trajectory data? How can we infer these mobility states from a single user’s trajectory information? How can we further generalize the mobility inference to the real-world trajectory data that span multiple users and are sparsely sampled over time? In this article, based on formal and rigid definitions of the stay/travel mobility, we propose a single trajectory inference algorithm that utilizes a generic long-tailed sparsity pattern in the large-scale trajectory data. The algorithm guarantees a 100% precision in the stay/travel inference with a provable lower bound in the recall metric. Furthermore, we design a transformer-like deep learning architecture on the problem of mobility inference from multiple sparse trajectories. Several adaptations from the standard transformer network structure are introduced, including the singleton design to avoid the negative effect of sparse labels in the decoder side, the customized space-time embedding on features of location records, and the mask apparatus at the output side for loss function correction. Evaluations on three trajectory datasets of 40 million urban users validate the performance guarantees of the proposed inference algorithm and demonstrate the superiority of our deep learning model, in comparison to sequence learning methods in the literature. On extremely sparse trajectories, the deep learning model improves from the single trajectory inference algorithm with more than two times of overall and F1 accuracy. The model also generalizes to large-scale trajectory data from different sources with good scalability.