Mei-Po Kwan

• PhD (University of California, Santa Barbara)
• Professor (Full) at Chinese University of Hong Kong

Any study that examines the effects of area-based attributes on individual behaviors or outcomes faces another fundamental methodological problem besides the modifiable areal unit problem (MAUP). It is the problem that results about these effects can be affected by how contextual units or neighborhoods are geographically delineated and the extent t...

Ignoring people’s daily mobility and exposures to nonresidential contexts may lead to erroneous results in epidemiological studies of people’s exposures to and the health impact of environmental factors. This paper identifies and describes a phenomenon called neighborhood effect averaging, which may significantly confound the neighborhood effect as...

This article draws on recent studies to argue that researchers need to be attentive to the limits of the neighborhood effect as conventionally understood. It highlights the complexities of contextual influences and the challenges in accurately representing and measuring individual exposures to those influences. Specifically, it discusses the idiosy...

Drawing on examples from human mobility research, I argue in this article that the advent of big data has significantly increased the role of algorithms in mediating the geographic knowledge production process. This increased centrality of algorithmic mediation introduces much more uncertainty to the geographic knowledge generated when compared to...

Many fundamental notions in geographic and social science research still tend to be conceptualized largely in static spatial terms, ignoring how our understanding of the issues we study can be greatly enriched through the lenses of time and human mobility. This article revisits three such notions: racial segregation, environmental exposure, and acc...

The COVID-19 pandemic has drastically altered urban transportation patterns, leading to significant changes in people’s daily travel behavior. Scholars have attributed this shift to individuals’ perceived pandemic risk, suggesting that higher perceived risk discourages daily travel. However, existing research has produced mixed results regarding th...

Transport and health studies need elaborated contextual information to establish causally relevant associations between built environment factors, mobility characteristics, and health outcomes. However, current approaches face various challenges in reliably obtaining contextual attributes. Therefore, investigating the capability of combining contex...

Crime is a significant social, economic, and legal issue. This research presents an open-access spatiotemporal repository of street and neighborhood crime data, comprising approximately one million records of crimes in China, with specific geographic coordinates (latitude and longitude) and timestamps for each incident. The dataset is based on publ...

Leveraging human mobility data has advanced the understanding of the effect of contextual factors on health and behaviors by mitigating the uncertain geographic context problem (UGCoP)––a source of inferential errors that occur due to the misspecification of a geographic context in which individuals interact with environmental factors and other peo...

Aims To examine the relationship between lipid profile and non-alcoholic fatty liver (NAFL), compare the predictive strengths of different lipid indicators to NAFL, and explore the possible mechanisms. Methods Male workers from a baseline survey of a cohort of workers in southern China were included. Basic information was collected through face-to...

Ensuring adequate access to healthy food is essential for public health. As a rapidly growing food access channel, online food delivery (OFD) services have gained widespread popularity globally, particularly in China. However, the accessibility of food through OFD retailers remains underexplored. This study addresses this gap by analyzing comprehen...

China has dedicated significant efforts to preventing obesity, but the rising prevalence of overweight and obesity remains a pressing public health issue. Therefore, unique solutions are required to address this challenge in China. As a research priority, the food environment plays a pivotal role in addressing overweight and obesity. However, resea...

Reducing global carbon dioxide (CO2 ) emissions is essential for meeting climate change mitigation goals, especially in urban areas. In this regard, this study used CO2 emissions and energy transition data from 296 China’s cities in 2020 and the extended Stochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) model to ex...

We aimed to assess the association of health locus of control with anxiety and depression, and explore the mediating effects of health risk behaviors. A multi-stage cluster random sampling method was used among Chinese college students. Logistic regression models were used to explore the associations of health locus of control with anxiety and depr...

Urban parks play a crucial role in human health and well-being, such as promoting physical activity (PA). However, past studies on park-based PA often overlooked other PA characteristics beyond the amount of PA. To bridge this gap, we explored what environmental factors are significantly associated with PA amount, intensity, and diversity, utilizin...

Global environmental issues are becoming increasingly serious. As a comprehensive indicator of environmental pressure, the material footprint reflects changing pressures amidst sustainable resource utilization. In this research, we conducted a time series prediction of material footprint using the Multi-Feature CNN-BiLSTM model and analyzed the mat...

As a crucial spatial constraint, directional relationships play an essential role in advanced spatial queries, spatial reasoning, image analysis, spatial indexing, and a variety of other applications. This paper concentrates on spatial cognitive tendencies and multiscale formal frameworks of directional associations within diverse contexts. We deve...

Agriculture is an important contributor to air pollution and its health impacts, with ramifications for environmental and health inequity. A substantial fraction of these effects can be attributable to dietary changes, but the extent of such impacts remains unclear. Here we show that the PM2.5-related mortality attributable specifically to dietary...

This study examines the impact of individual socioeconomic factors, living environment factors (e.g., housing conditions), and environmental exposures (e.g., greenspace) on people's mental health during the COVID-19 pandemic in Hong Kong. We measured the environmental exposures to greenspace, noise and air pollution using GPS tracking and mobile se...

This study aims to explore the spatial heterogeneity of influential factors of integrated use of ride-hailing service with the metro. Using the operation data of ride-hailing services in Chengdu, China, first, an identification method of integrated ride-hailing trips is proposed. Then, the ordinary least squares (OLS) and geographically weighted re...

Equal exposure to quality-built environments fosters livable, inclusive cities. The neighborhood effect averaging problem (NEAP) suggests that daily mobility plays a crucial role in shaping environmental exposure. This study aims to unveil the NEAP in built-environment quality exposure. Street-view image data and mobile phone signaling data are cou...

The COVID-19 pandemic has had an unprecedented impact on public travel and has significantly altered people’s travel behavior. By comparing the travel behaviors of ride-hailing passengers before and after the pandemic (i.e., the pre-pandemic era and the post-pandemic era), it is possible to effectively identify the changes in their travel patterns...

This paper proposes a diversity identification method based on information fusion for quantitatively identifying mixed urban functional zones (UFZ), addressing the critical need for better city planning and management. This method integrates both social and physical sensing data, considering the frequency of urban functional occurrences and the int...

An accurate understanding of noise perception is important for urban planning, noise management and public health. However, the visual and acoustic urban landscapes are intrinsically linked: the intricate interplay between what we see and hear shapes noise perception in the urban environment. To measure this complex and mixed effect, we conducted a...

Community dependence reflects individuals' daily needs for community space and facilities and is closely related to the accurate allocation of social resources and human quality of life. This study examines the differences in community use and dependence among different income groups at the overall and community levels from the perspective of the m...

This study formulates the order dispatch problem of the inter-city/inter-district ridesplitting service as an integer linear programming, and a solution framework that combines Lagrangian relaxation (LR) and alternating direction methods of multipliers is constructed. Specifically, LR problem is constructed by relaxing coupling constraints; based o...

The urgency to combat climate change has led countries worldwide to embrace clean energy solutions across various sectors, including transportation, to reduce greenhouse gas emissions. This shift is evident in the growing popularity and adoption of alternative fuel vehicles (AFVs), such as natural gas vehicles and electric vehicles. AFVs have signi...

The neighborhood effect averaging problem (NEAP) is a fundamental statistical phenomenon in mobility-dependent environmental exposures. It suggests that individual environmental exposures tend toward the average exposure in the study area when considering human mobility. However, the universality of the NEAP across various environmental exposures a...

Mental stress issues are emerging among residents of modern cities. Among environmental factors associated with stress mitigation, greenspace has consistently been shown to have significant stress-reducing properties. However, the temporality of greenspace exposure, particularly the cumulative threshold effect in urban environments, has been largel...

Advanced techniques in Geographic Information Systems (GIS) currently provide one of the most promising approaches to investigating the health impacts of green space. The GIS solution of deriving causally relevant green space exposures still faces challenges from the arbitrary determination of the contextual unit size. This paper presents an in-dep...

This study seeks to reveal urban noise exposure patterns and inequalities using noise complaint data and vision-language hybrid method. By applying a natural language processing model to 17,243 noise complaint records, we uncovered distinct patterns of traffic, industrial, and living noise exposures across residential communities. Our analysis of s...

The '15-minute city' (15minC) concept, which aspires to bring essential services within reach via a 15-minute walk for all residents, represents a pivotal paradigm shift in sustainable urban development. However, the achievability of this concept for different cities varies considerably across diverse population distributions, urban contexts, and d...

Spatial epidemiology recognizes the impact of environmental factors on human infectious diseases through disease vectors. The expansion of Aedes aegypti and Aedes albopictus raises concerns about health risks due to their changing distribution. However, current mosquito mapping methods have low spatial resolution and limited focus on long-term tren...

Excessive urbanization leads to considerable nature deficiency and abundant artificial infrastructure in urban areas, which triggered intensive discussions on people’s exposure to green space and outdoor artificial light at night (ALAN). Recent academic progress highlights that people’s exposure to green space and outdoor ALAN may be confounders of...

The rapid pace of urbanization and population growth has led to heightened traffic congestion and extended commuting distances, consequently amplifying uncertainties in travel times. For decades, studies have employed average or median travel time to assess job accessibility while neglecting variations and uncertainty in travel time, ultimately lea...

Greenspaces are crucial for enhancing mental and physical health. Recent research has shifted from static methods of assessing exposure to greenspaces, based on fixed locations, to dynamic approaches that account for individual mobility. These dynamic evaluations utilize advanced technologies like GPS tracking and remote sensing to provide more pre...

Monitoring urban structure and development requires high-quality data at high spatio-temporal resolution. While traditional censuses have provided foundational insights into demographic and socio-economic aspects of urban life, their pace may not always align with the pace of urban development. To complement these traditional methods, we explore th...

The rapidly aging population demands more public and academic attention to both the physical and psychological needs of older adults. Walking is one of the most favored forms of transportation and exercise for older adults. Hence, the conditions of walkways and the built environment are critical for the development of an older adults-friendly socie...

Advanced nighttime light (NTL) remote sensing techniques enable the large-scope epidemiological investigations of people’s exposure to outdoor artificial light at night (ALAN) and its health effects. However, multiple uncertainties remain in the measurements of people’s exposure to outdoor ALAN, including the representations of outdoor ALAN, the co...

Urban greenspaces are pivotal in enhancing the well-being and health of city residents. Accurate assessment of an individual's exposure to these natural settings is thus crucial in urban greenspace planning. However, the dynamic nature of human mobility, which determines the amount of greenspace exposure accessed over time and space, often leads to...

Air pollution poses a threat to human health. Public perceptions of air pollution are important for individual self-protection and policy-making. Given the uncertainty faced by residence-based exposure (RB) measurements, this study measures individuals’ real-time mobility-based (MB) exposures and perceptions of air pollution by considering people’s...

It is common to observe the epidemic risk perception (ERP) and a decline in subjective well-being (SWB) in the context of public health events, such as Corona Virus Disease 2019 (COVID-19). However, there have been few studies exploring the impact of individuals’ ERP within living space on their SWB, especially from a geographical and daily activit...

Developing walkable urban environments is crucial for enhancing urban liveability and sustainability. To evaluate the chrono‐urbanism status, this study combines conventional census and mapping data with social media check‐in big data. A composite index is proposed, which assesses the accessibility of essential urban functions under the 5/10/15‐min...

The reduction of social interactions through non-pharmaceutical interventions (NPIs) has been shown to effectively curb COVID-19 transmission. However, these control measures were often accompanied by changes in people’s daily routines and constraints on their activity space, which could lead to mental distress (i.e., anxiety and depression). This...

In order to gain a comprehension of the impact of COVID-19 pandemic on the ride-hailing service and the potential role of the ride-hailing played in this period, this study investigates the impact mechanism of usage frequency of ride-hailing users before and after the outbreak of COVID-19. Utilizing the questionnaire collected in Nanjing, China, we...

Considering that the number of wheelchair users is on the rise at the global level due to population aging, it is crucial to secure their rights to have adequate access to healthcare services. Spatial accessibility to healthcare services has been well recognized to influence people's health. However, research on healthcare accessibility of wheelcha...

Background As the COVID-19 pandemic became a major global health crisis, many COVID-19 control measures that use individual-level georeferenced data (e.g., the locations of people’s residences and activities) have been used in different countries around the world. Because these measures involve some disclosure risk and have the potential for privac...

Urbanization has led to environmental challenges, with the urban heat island effect being a prominent concern. Understanding the influence of urban environmental characteristics (UECs) on land surface temperature (LST) is essential for addressing this issue and promoting sustainable urban development. The spatiotemporal characteristics and influenc...

Urban buildings are an integral component of urban space, and accurately identifying their spatial configurations and grouping them is vital for various urban applications. However, most existing building clustering methods only utilize the original spatial and nonspatial features of buildings, disregarding the potential value of complementary info...

Land subsidence, a common geological phenomenon in deltaic regions, poses significant risks to infrastructures, environments, and human lives. Monitoring and understanding land subsidence are crucial for establishing resilient, adaptive, and sustainable environments. In this study, a robust multi-temporal interferometric synthetic aperture radar (M...

Air pollution perception biases hinder the public's awareness of actual air quality. Past studies that examined the association and mismatch between actual and perceived air quality neglected individuals’ dynamic exposure and their activity, travel, spatial, temporal, and social contexts. Using data collected with real-time air pollutant sensors an...

People's exposure to green space is a critical link between urban green space and urban residents' health. Since green space may affect human health through multiple pathways regarding diverse human health outcomes, the measurement of people's exposure to green space must be tailored to concrete study contexts and research questions. In this scopin...

Machine learning (ML) and deep learning (DL) have exhibited significant advantages compared to conventional data analysis methods. However, the limitations of poor generalization and extendibility impede the broader application of these methods beyond specific learning tasks. To address this challenge, this study proposes a transfer learning-based...

Causal inference in complex systems has been largely promoted by the proposal of some advanced temporal causation models. However, temporal models have serious limitations when time series data are not available or present insignificant variations, which causes a common challenge for earth system science. Meanwhile, there are few spatial causation...

Background: Metabolic syndrome (MetS) is a common metabolic disorder that results from the increasing prevalence of obesity, which has been an increasing concern in recent years. Previous evidence indicated that MetS was associated with mortality; however, different definitions of MetS were used. In 2005, the National Cholesterol Education Program...

Introduction Promoting a walkable environment is a prime concern for aging societies, including Japan. This study focuses on the daily shopping environment of older adults in Yokohama City and analyzes the association between their daily step counts and spatial accessibility to grocery stores. We aim to discover a reasonable distance to and the spa...

Using individual-level data collected from two communities in Hong Kong, this study proposes a significant association rule mining method to identify the complex associations between individual socioeconomic characteristics and perceived air pollution in people’s daily life. It defines a measure, namely the rule inequality index, to assess the soci...

This study investigates how people’s perceived COVID-19 risk, worries about financial hardship, job loss, and family conflicts, and exposures to greenspace, PM2.5, and noise (in people’s residential neighborhoods and daily activity locations) are related to their depression, anxiety, and stress during the COVID-19 pandemic. Using a two-day activity...

Sandwich composites are prone to delamination and fracture during service when exposed to external low-velocity impact. One hindrance to overcome before a broader deployment of sandwich composites is the issue of impact energy assessment (IEA). To promote the solution to this issue, an ensemble deep learning approach is proposed in this study. The...

A place reflects the collective cognition of the geographical extent and semantics of a named spatial domain, acting as a vital reference to a particular space in daily discourse. Boundaries and toponyms are essential identifiers of places. Frameworks that are efficient in real-world boundary determination of cognitive places are still missing. The...

Earth system modelling (ESM) is essential for understanding past, present and future Earth processes. Deep learning (DL), with the data-driven strength of neural networks, has promise for improving ESM by exploiting information from Big Data. Yet existing hybrid ESMs largely have deep neural networks incorporated only during the initial stage of mo...