Unsupervised Short-Term Monitoring of Human-Induced Land Cover Change Using Repeat-Pass RADARSAT-2 Polarimetric SAR Images (Prof. Anthony Yeh, Department of Urban Planning and Design, The University of Hong Kong), Hong Kong Research Grants Council, 2015 - 2017

A major issue confronting China today is the illegal use of land for development. Illegal land use has resulted in a rapid decline in the supply of arable land and posed a major threat to healthy urban development. Timely information on land development activities is essential for identifying unauthorized expansion of construction land. Land development is commonly accompanied by drastic land cover changes induced by human construction activities. Therefore, short-term monitoring of human-induced land cover changes is important for detecting and preventing illegal land development at an early stage. However, conventional optical remote sensing is limited by weather conditions and has difficulties in collecting timely land cover information in regions frequently covered by clouds. Spaceborne polarimetric synthetic aperture radar (PolSAR) remote sensing is independent of weather conditions and day light as well as provides multi-polarization SAR data that outperforms traditional single-polarization SAR data in land cover classification. Therefore, it is a promising tool for short-term monitoring of land cover changes. Post-classification comparison (PCC) is commonly used in land cover change detection with remote sensing images because it not only detects changed areas but also provides the type of change these areas undergo. However, PCC is limited by the accuracy of the classification. PolSAR images suffer from serious speckle noise and most existing orbital PolSAR systems are single-frequency types. When applied to PolSAR images, PCC may yield poor results because of the low classification accuracies caused by the speckle effect and limited spectral information. Furthermore, most classification methods are supervised methods, which are performed based on training samples that are commonly selected in field work. In short-term monitoring of land cover changes, field work needs to be conducted frequently to collect ground truth data. It will consume a lot of time, money, and manpower. In addition, seasonal vegetation growth may pose difficulties for short-term monitoring of human-induced land cover changes. Seasonal growth of agricultural and natural vegetation can cause many land cover changes that may be easily confused with changes caused by construction activities, and thus produce false alarms to the detection of human-induced land cover changes. The objective of this study is to develop methods for unsupervised short-term monitoring of human-induced land cover changes using repeat-pass RADARSAT-PolSAR images. The study will explore a new method that integrates unsupervised change detection techniques and PCC with object-oriented image analysis to detect land cover changes from PolSAR images. The method is expected to greatly improve the accuracy of land cover change detection by reducing the effect of the classification errors and speckle noise. A decision tree-based hierarchical clustering method will be developed for the classification of PolSAR images. Hierarchical clustering is implemented according to the dendrogram of a pre-defined decision tree to classify images acquired on different dates. This can perform land cover classification of PolSAR images without using any training dataset. The study will also develop a new method that can automatically distinguish human-induced land cover changes from changes caused by seasonal vegetation growth. Interferometric information and multi-temporal land cover information extracted from successive repeat-pass PolSAR images will be used to identify changes caused by human construction activities.



Integrating Spatio-Temporal Analysis and Molecular Epidemiology to Study the Transmission of Tuberculosis in China (Prof. P.C. Lai (Department of Geography, The University of Hong Kong) and Prof. X. Wei (Chinese University of Hong Kong)), Hong Kong Research Grants Council Competitive Bid's Awards 2014-15, 10/14-09/17

Abstract: The proposed research aims to mobilize the recently available large databases of over 6000 genotyped TB samples in China, and to develop a rigorous and integrated approach to analyze TB transmission. First, the process of TB will be analyzed under multiple spatial and temporal scales to find out whether the disease is heterogeneous in space and time. Second, bacterial evolution will be analyzed based on over 6000 genotyped samples collected from disease surveillance and cohort studies in China. Linking with the spatio-temporal analysis, this study will generate a direct picture for the process of TB transmission at both macro- and micro scales. The project will specifically study the effects of people migrations on TB transmission as China has the largest internal migrants worldwide. This research will advance both scientific and systematic approaches in the study of TB transmission and pave a solid foundation for relevant infectious disease studies.

Unsupervised Short-Term Monitoring of Human-Induced Land Cover Change Using Repeat-Pass RADARSAT-2 Polarimetric SAR Images (Prof. Anthony Yeh and Dr. Zhixin Qi, Department of Urban Planning and Design, The University of Hong Kong), Science and Operational Applications Research (SOAR) programme, Canadian Space Agency (CSA) and Natural Resources Canada's Centre for Remote Sensing (CCRS), 2014- 2017

There are many illegal land use sites in some developing countries such as China that are experiencing a process of rapid urbanization. Short-term (e.g., monthly) monitoring of human-induced land cover changes is important for detecting illegal land use at its early stage. Optical sensors have difficulties in collecting timely land cover information in regions frequently covered by clouds. Radar remote sensing, not affected by clouds, can overcome these difficulties. Polarimetric SAR (PolSAR) provides multi-polarization information, which leads to a significant improvement in the quality of land cover classification, is a promising tool for short-term monitoring of land cover changes. Post-classification comparison (PCC) is widely used for change detection because it provides information on both change areas and the type of change these areas undergo. However, the accuracy of PCC is limited by the classification accuracy. It is still difficult to achieve high accuracy for PolSAR image classification due to speckles and limited spectral information in PolSAR data. Moreover, most classification methods are supervised methods, which are performed based on ground truth data commonly collected in field work. The collection of ground truth often costs a lot of time and labor. In addition, seasonal vegetation growth poses difficulties for the monitoring of human-induced land cover changes because seasonal land cove changes caused by vegetation growth are easily confused with human-induced changes. The overall objective of this study is to explore methods for unsupervised short-term monitoring of human-induced land cover changes using RADARSAT-2 images. To achieve this objective, the aforementioned technical issues must be addressed. The research objectives are summarized as follows: 1) To develop a new land cover change detection method using RADARSAT-2 images. The method is expected to greatly reduce the effect of the error of independent classification. Moreover, the method can reduce the speckle effect and extract textural and spatial information for improving land cover classification accuracy. 2) To explore a new land cover classification method using RADARSAT-2 images. The method can be used to extract land cover information from PolSAR images without using any training samples. 3) To develop a new method for discriminating human-induced land cover changes from seasonal vegetation changes. The study should be useful in monitoring and controlling illegal land use in rapidly developing regions in China and other parts of the world which are under a rapid urbanization. The new change detection and classification methods for PolSAR data have potential to achieve high accuracy for monitoring land cover changes without conducting field investigation. The new method for discriminating human-induced changes from seasonal vegetation changes can promote the application of RADARSAT-2 images in mapping land use changes.

The Hong Kong D3D Study: A Dynamic Three-Dimensional Exposure Model for Hong Kong (M. Brauer, CM Wong, TQ Thach, HK Lai (Health Effects Institute) and PC Lai (Department of Geography, The University of Hong Kong)), Health Effects Institute, 01/03/2014 to 28/02/2017. RFA 13-1

Abstract: The proposed study has the overarching aim of creating a dynamic three dimensional (3D) exposure model for Hong Kong (HK), with a fully evaluated methodology that can be applied to other large cities, especially Asian megacities. The study has three main objectives: (1) to investigate the behaviour and distribution of vehicle emissions in a three dimensional (3D) urban landscape with high residential and traffic density; (2) to develop a detailed air pollution exposure model for Hong Kong (HK), incorporating population mobility, vertical and horizontal vehicle emission profiles, physical geography and land use; and (3) to create an incremental exposure assessment methodology that balances exposure error with input data availability, and is therefore applicable to other megacities across Asia and the developing world.

Measuring and modelling Quality of Urban Life (QOUL) in Hong Kong - An Asian Perspective (Prof. P.C. Lai (Department of Geography, The University of Hong Kong), E. Cerin and R. Stimpson (University of Melbourne)), Hong Kong Research Grants Council Competitive Bid's Awards 2013-14, 01/14-12/16. HKU 744113

Abstract: The research will use both existing and new methodologies to assess the quality of urban life (QOUL) in Hong Kong, about which there is a paucity of detailed analysis and systematic understanding. This research aims at examining the city planning approaches to quality of life, well-being, and liveability focussing specifically on the quality of the urban environment and neighbourhood design. This study proposes a three-staged research process: (1) apply the GIS technique to abstract objective measures of the physical layout and structure of neighbourhoods; (2) employ a social survey to collect subjective perception of neighbourhoods; and (3) establish agreements and disagreements of a range of objective variables and subjective well-being to arrive at a small number of well-chosen QOUL indicators for Asian cities that are more focussed and easily understood.



IPEN adolescent: International Study of Built Environments and Physical Activity (J.F. Sallis et al. (San Diego State University), and P.C. Lai (Department of Geography, The University of Hong Kong)), National Institute of Health, 04/12-03/16. AN3367041, NIH R01-NH111378

Abstract: This study will estimate strengths of associations of measures of the built environment with physical activity and weight status in adolescents based on data collected according to a common protocol in a collaborative international study.

Healthy Ageing and Sustainable Transport (Prof. Becky P.Y. Loo, Department of Geography), The University of Hong Kong, 27 th Round PDF/RAP Scheme, 7th September, 2012 - 6th September, 2015

The Geospatial Education Forum (GEF): Resolving the challenges of a New Geospatial Education Curriculum (Prof. P.C. Lai (Department of Geography, The University of Hong Kong) and Dr. B. King (Hong Kong Polytechnic University)), UGC's Additional Funding for Teaching and Learning Related Initiatives for the 2012-15 Triennium, 04/14-08/15

Abstract: The sphere of application of geospatial information and technology (GIT) encompasses social science, tourism, engineering, political science, health, agriculture, logistics, finance, and business. Geospatial Education (GeoEd) encompasses these disciplines (and more), but each has its own concept of what constitutes geospatial information in their own fields. In order to circumvent these problematic characteristics and to create a synergy between disciplines a review of the curriculum of GeoEd, in the broadest of senses, is required. Such a review should lead to a wider understanding of the foci of the various disciplines; encourage cross-fertilisation of teaching skills and strategies; and produce graduates with greater visions of the potentials of GIT.

Past Research

Angle Difference Method for Vehicle Navigation in Multi-level Road Networks with Three Dimensional GIS-T (Prof. Anthony Yeh, Mr. Zhong Teng (Department of Urban Planning, The University of Hong Kong) and Dr. Yue Yang (Shenzhen Key Laboratory of Spatial Smart Sensing and Services, Shenzhen University)), Chinese Patent No. CN 101424535 B

Multi-level road networks such as grade-separated interchanges and elevated roads have been increasingly used to solve traffic congestion in large cities. When navigating a vehicle in a multi-level road network, identifying the location of the vehicle in different road levels is of equal importance as identifying its planar location, especially for overlapping and parallel roads. Although they can be represented and visualized in the existing navigation system, at present, it is difficult to guide a vehicle through such multi-level road network because the existing vehicle positioning system and GIS-T database is mainly 2D-based that focus on planar positioning (i.e., (x, y)-based) and the position of the vehicle on different road levels in multi-level road networks is often overlooked. This paper examines the deficiency of existing approaches in supporting vehicle navigation in multi-level road networks. It proposes to use an angle difference method that compares the vehicle inclination angle with the slope angles of different road levels calculated from road elevations stored in the proposed GIS-T database to snap the vehicle to the appropriate road level when the vehicle is entering a multi-level road network.

2015
The 8th Greater China GIS Conference
The 8th Greater China GIS Conference was held from 7th to 9th January 2015 at the University of Hong Kong. This Conference is a joint Conference of the GIS associations in the Mainland, Taiwan, Macau and Hong Kong. The first Conference was held in 1998 and thereafter it is organized once every two years by rotation. The Hong Kong Geographic Information System Association (HKGISA) organized this Conference and co-organized by the China Association for Geographic Information Service, Taiwan Geographic Information Society and the Cartography and Cadastre Bureau of the Macau SAR Government. The conference is sponsored by the Centre of Urban Studies and Urban Planning of the University of Hong Kong. The main objective of this Conference is to provide an interactive platform for the GIS academics and practitioners from the Mainland, Taiwan, Macau and Hong Kong to exchange views and ideas about the latest developments in GIS research and application. The Conference was participated by over 180 participants and seven exhibitors from both the public and private sector set up booths to display their GIS products and services.







Workshop: Introduction to the "Understanding the World with Geography" E-Textbook
17 Jan 2015 & 24 Jan 2015, Introduction to the "Understanding the World with Geography" e-textbook, GIS workshop held at the Department of Geography, The University of Hong Kong


2014
Research Seminars: A Quantitative Approach to Understand Urban Morphology and Urban Design for Promoting University: "Form Syntax" Method
14 February 2014, A Quantitative Approach to Understand Urban Morphology and Urban Design for Promoting University: "Form Syntax" Method, Presented by Mr. Yu Ye, held at the Department of Urban Planning and Design, The University of Hong Kong


2013
Research Seminars: Smart City - Concept, Technology and Applications
7 May 2013, Smart City - Concept, Technology and Applications, presented by Prof. Deren Li, held at the Department of Geography, The University of Hong Kong.

Research Seminars: Activity-travel Behavior Analysis and Its Application in Smart Travel Planning: A Case Study in Beijing
11 December 2013, Activity-travel Behavior Analysis and Its Application in Smart Travel Planning: A Case Study in Beijing, presented by Prof. Yanwei Cai, held at the Department of Urban Planning and Design, The University of Hong Kong

Research Seminars: Augmenting Ecosystem Services with Urban Green Infrastructure: Planning and Development Regimes in Hong Kong
28 Nov 2013, Augmenting ecosystem services with urban green infrastructure: planning and development regimes in Hong Kong, presented by Janice C.Y. Tse, held at the Department of Geography, The University of Hong Kong.

Research Seminars: Compactness of Resident's Living and Employment Activities - A Mobile Phone Data Approach
7 August 2013, Compactness of Resident's Living and Employment Activities - A Mobile Phone Data Approach, presented by Mr. Xingang Zhou, held at the Department of Urban Planning and Design, The University of Hong Kong


2012
Research Seminars: Identifying Objective Measures about Environmental Aspects of the Urban Quality of Life Index
29 Nov 2012, Identifying Objective Measures about Environmental Aspects of the Urban Quality of Life Index, presented by Si Chen, held at the Department of Geography, The University of Hong Kong


2010
Research Seminars: Spatio-Temporal Transmission Modelling of An Infectious Disease: A Case Study of the 2003 SARS Outbreak in Hong Kong
25 Feb 2010, Spatio-temporal transmission modelling of an infectious disease: a case study of the 2003 SARS outbreak in Hong Kong, presented by KH Kwong, held at the Department of Geography, The University of Hong Kong

Ongoing Research
A Study of Urban Living and Employment Compactness Based on Multi-source Spatio-temporal Data Characters (Prof. Anthony Yeh and Dr. Weifeng Li, Department of Urban Planning and Design, The University of Hong Kong), National Science Foundation China (NSFC), 01/15-12/18.

Rapid urbanization in China has led to a set of urban problems such as traffic congestion, energy consumption, which may affect sustainable development. One of the problems is mismatch between activities and spatial structures. Urban planning in China has been promoting compact city characterized as high-density and mixed land use development for many years. However, compact urban form, compact land use and facilities are not real goals of fulfilling a compact city. Achieving high quality and compactness of urban living and employment are the key issues of sustainable development. The availability of big data from mobile phones and smart cards enable us to have better knowledge of travel pattern and behaviours. To recognize and extract residents' living and commuting activity pattern from big data is one key scientific question. The other scientific question is how to demonstrate the evolving dynamics of urban systems by integrating the big data with the traditional land use and transportation data. This project examines the analysis of big data for the investigating the compactness of urban living and employment and to find the relationships between the measurement of compactness from traditional land use analysis and actual people's activity space from big data. The project will further advance the theory of compact city, filling in the research gap that traditional urban planning practice cannot match spatial structure and urban micro-economic activities. It will develop the bottom-up activity based urban planning theoretical framework by the use of big data which is of great significance to sustainable urban spatial development and smart urban planning.


Remote Sensing Monitoring of PM2.5 Concentrations and Analysis of Socio-economic Driving Forces in Beijing-Tianjin-Hebei Based on VIIRS Data (Dr. Weifeng Li, Department of Urban Planning and Design, The University of Hong Kong), National Science Foundation China (NSFC), 01/2015-12/2018.

While Beijing is not alone when it comes to smoke-filled skies, this city has come to symbolize the environmental cost of China's break-neck economic growth. It has been a heated topic for discussion that also leads to health concerns greatly. Health studies have shown a significant association between exposure to fine particulates and premature death from heart or lung disease. There are limited air quality monitor stations in a city, though, air quality varies in urban spaces non-linearly and depends on multiple factors, such as meteorology, traffic volume, and land uses. Satellite remote sensing for air quality monitoring has advanced significantly in recent years, however, there are still inherent weaknesses and challenges in the use of this technology. This research is one of the earliest attempts to associate remote sensed aerosol optical depth (AOD) to ground-level PM2.5 data in China since the public release of ground-level PM2.5 data in more than 500 stations in early 2013. It aims to calculate correlations of AOD retrieved by the Visible Infrared Imaging Radiometer Suite (VIIRS) and hourly PM2.5 readings from the monitoring stations and develop statistical models, which also include meteorological factors, to assess the relationship between remotely sensed AOD and PM2.5 in the Beijing-Tianjin-Hebei region. The spatial and temporal variation of PM2.5 concentrations derived from remote sensing data, will also be regressed on land use, road traffic, population and human activities data. The spatial statistical models will be used to explore the role of the driving forces, such as population, land use, transportation, and urban activates, and to simulate the impacts of different policy scenarios on air quality in the near future.




Neighbourhood Design and Energy Efficiency in Post-industrial Urban China: Evidence from Shenzhen and Hong Kong (Dr. Weifeng Li, Department of Urban Planning and Design, The University of Hong Kong), Hong Kong Research Grants Council, 2015-2017.

Achieving low carbon urban development in China requires a combination of approaches. Energy supply-side measures alone cannot provide the solution to China's or the world's challenge. More understanding of the household demand side is necessary to make relevant policies to potentially influence the behaviours of urban energy end-users. This research aims to take a step further by seeking to understand the potential of alternative urban form and neighbourhood design in relation to energy efficiency, and to answer the question of how neighbourhood design affects a household's direct energy consumption as well as carbon emissions, through the influence on urban household's lifestyle in post-industrial Chinese cities. It also aims to fill the gaps in the literature, by piloting a theoretical framework to integrate the two main sources of direct energy consumption, in-home use and personal travel, with empirical evidence in China's urban context, through the influence of urban households' lifestyles. The disaggregated household-level survey data with rich demographic and socio-economic information, collected from both Hong Kong - one of the most densely populated city, and Shenzhen - a newly emerging city, will be used for a mixed qualitative-quantitative study. An important methodological contribution of the study to the relationship between built environment, travel behaviour and household energy consumption is to provide new insights of the interaction of residence and mobility as a lifestyle bundle, and clarify the role of urban form and neighbourhood design in influencing a household's lifestyle choice with respect to energy consumption and carbon emission.


Convenience of Play Space in Local Neighbourhoods of Hong Kong - A Study to Determine the Ease of Accessing Quality Play Space by Disabled Children and Their Families (Prof. P.C. Lai, Department of Geography, The University of Hong Kong), UNICEF Child Rights Advocacy Project, 01/16-12/17.

Abstract: The proposed project focuses on physical inaccessibility of play space by disabled children and their families. This study will adopt GIS methods to measure three indicators of convenience pertaining to play space: accessibility, quality and quantity. A number spatial data layers (e.g. transportation, population density, demographics, land use, etc.) will be integrated in a GIS to uncover areas in need of improvement or provision of more quality play space. The conditions of play space will also be assessed through environmental audits and site visits. This project expects to provide evidence-based information on accessibility, quality, and quantity of play space in Hong Kong to inform policy makers where the needs of the community are not being met, as well as possible locations and areas of improvement.



Bicycle Injury Prevention Program in Tuen Mun District (S.C. Wong (Department of Civil Engineering), N.N. Sze, Becky P.Y. Loo (Department of Geography), K.L. Tsui, F.L. So, H.S. Lee and S.S. So), Health Care and Promotion Fund Committee, Food and Health Bureau, Hong Kong SAR Government (24100244), 1st September, 2011 - 28th February, 2013


Understanding and Enhancing the Mobility and Safety of Elderly Pedestrians (Becky P.Y. Loo (Department of Geography) and K.L. Tsui ), RGC GRF (HKU 749210), 1st January, 2011 - 30th June, 2013


Home and Neighbourhood Environment: Associations with Children's Physical Activity and Obesity-Related Dietary Behaviours (H.S. Wong, et al. (Department of Sports Science and Physical Education, The Chinese University of Hong Kong), and P.C. Lai (Department of Geography, The University of Hong Kong)), Health and Health Services Research Fund, Food and Health Bureau, 01/12-06/13

Abstract: This study aims to: (1) examine the associations of home and neighbourhood environment with physical activity (PA); (2) examine the associations of home and neighbourhood environment with obesity-inducing dietary behaviours; and (3) examine the relative contribution of psychosocial, environmental, and behavioural factors (PA and above-mentioned dietary behaviours) to body mass index (BMI), among school children in Hong Kong.



Monthly Short-Term Detection of Land Development Using RADARSAT-2 Polarimetric SAR Imagery (Prof. Anthony Yeh, Dr. Zhixin Qi (Department of Urban Planning, The University of Hong Kong) and Prof. Xia Li (School of Geography and Planning, Sun Yat-sen University)), 2009-2011

Regular land development detection on a short-term basis (monthly or multi-month) has grown in importance with increasing concern over the impact of rapid urbanization on the environment. Unauthorized urban land developments have caused considerable damage to the environment in many developing countries because they are difficult to be controlled using conventional long-term (annual or multi-year) monitoring with optical remote sensing images. This paper presents the results of a novel study that detects land developments monthly using RADARSAT-2 polarimetric synthetic aperture radar (PolSAR) data. A sequence of seven RADARSAT-2 PolSAR images acquired at intervals of 24 days was obtained for this study. Land cover classification of each image was performed independently to investigate the ability of RADARSAT-2 PolSAR data in classifying land cover types under the influence of environmental change and vegetation growth. Wishart maximum likelihood ratio (MLR) was combined with post-classification comparison (PCC) to detect land developments from each pair of successive images based on object-oriented image analysis (OOIA). The average detection accuracy and false alarm rate for monthly land development detection were 85.20% and 0.39%, respectively. The results show that land developments can be effectively detected from RADARSAT-2 PolSAR images on a monthly time step. Land development is typically a gradual expansion process. By the time that it is detected using long-term detection methods, the small development may have already been developed into a large site, causing irreversible damage to the environment. Monthly short-term detection of land developments can enable the authorities to locate the sites which just start the development. This can allow the government to prevent unauthorized land developments and stop their resulting damage to the environment at an early stage.




Climate Change and Environmental Health - the Impact of Thermal Stress on the Mortality and Morbidity in Urban Hong Kong: Development of a Coordinated Methodology Between Multidisciplinary Experts from Hong Kong and Germany (C.M. Wong, et.al. (Community Medicine and Kraemer, The University of Hong Kong, A. of University of Bielefeld), and P.C. Lai (Department of Geography, The University of Hong Kong)), Germany/Hong Kong Joint Research Scheme 2010/11, G_HK032/10, 01/2011-12/2012

Abstract: The effects of temperature are not equal among subgroups of the population. Previous studies in developed countries suggested that risks of temperature effects on cardiovascular and respiratory mortality were higher for several subgroups, including the persons with low socioeconomic status This project is the first step in collaboration with colleagues from Germany. The interdisciplinary consortium aims to develop a more comprehensive methodology to assess thermal stress and health outcomes. Additionally it strives to model the future development of thermal stress in urban areas beyond Hong Kong. A wide range of future projects not only in China and Germany but also in other geographical regions can get benefit from the results of this project. This will open the opportunity to compare results of both projects and to later test for the Hong Kong developed climate-health model in other sites also heavily affected by climate change.


A Cohort Study for Effects of Environmental Thermal Stress and Air Pollution on Mortality for the Older Population in Hong Kong (CM Wong, et. al.(Community Medicine, The University of Hong Kong) and P.C. Lai (Department of Geography, The University of Hong Kong)), Hong Kong Research Grants Council Competitive Bid's Awards 2012-13, 10/12-12/14. HKU 780512

Abstract: Thermal stress and air pollution are two major hazards resulting in substantial disease burden. Because of acclimatization, long term effects of thermal stress are difficult to assess. However it is biologically plausible that thermal stress and air pollution may interact. Long term exposure to higher thermal stress may lead to higher intake of air pollutant (particulate matter with aero-diameter < 10 μm i.e. PM10), and the observed effects should give information about long term effects of thermal stress. The objectives of the study include the following: (1) To assess the effects on mortality associated with long term exposure to PM10 and long term exposure to thermal stress through its interaction with PM10; and (2) To assess, for short term exposures, interaction between effects of thermal stress and air pollution with a view to clarifying the mechanism for temperature as an effect modifier for health effects of air pollution.



Understanding the Relative Contribution and Interactive Effects of Psychological, Social and Environmental Correlates of Physical Activity, Sedentary Behaviours and Dietary Behaviours in Hong Kong Adolescents (E. Cerin (Institute of Human Performance, The University of Hong Kong), J.F. Sallis (San Diego State University), and P.C. Lai (Department of Geography, The University of Hong Kong)), Health and Medical Research Fund, 09/12-08/14. 10111501

Abstract: This proposal aims to identify built environmental, social and individual factors associated with physical activity (PA), sedentary behaviours (SBs) and dietary behaviours (DBs) in Hong Kong adolescents. Acknowledging that PA, SBs and DBs are likely shaped by a large number of multi-level, interacting psychological, social and environmental factors, research in this field has been shifting from a psychosocial to a social ecological framework. This would be the first study to estimate the relative contribution and multilevel interactive effects of a wide array of individual, social and objective and perceived environmental factors on three main obesity-related behaviours in Hong Kong adolescents. Therefore, it would provide essential information for local intervention initiatives (e.g., programmes organised by the SHS, DH). It would also provide key data for international comparative studies aimed at discovering how diverse physical and social environments impact on obesity-related behaviours in adolescents.



Understanding the Impact of the Neighborhood Environment on Physical Activity, Quality of Life and Depressive Symptoms in Older Adults (E. Cerin, et al. (HKU Institute of Human Performance), and P.C. Lai (Department of Geography, The University of Hong Kong)), Hong Kong Research Grants Council Competitive Bid's Awards 2011-12, 01/12-12/14. HKU 741511

Abstract: Studies indicate that a large percentage of elders, in Hong Kong and elsewhere, do not meet the recommended physical activity (PA) guidelines for health. Most recent studies have examined determinants of PA and health in elders living in Western countries with built and socio-cultural environments much different to those of Asian cities. This study proposes to systematically examine the associations and interactive effects of a variety of environmental, individual and psychosocial factors with levels of PA, quality of life, and mental wellbeing in Hong Kong Chinese-speaking older adults (aged 65+). It is expected that the multi-dimensional and multi-method approach adopted in this study will substantially enhance the understanding of the mechanisms by which contextual factors may influence PA levels and wellbeing in elders which, in turn, will assist policy makers and healthcare professionals in the development of PA promotion approaches suited to this population.

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Ongoing Research