Tropical Environmental Change (TEC)

The Research Group


The Tropical Environmental Change (TEC) research group in the Department of Geography, NUS, currently comprises around 35 faculty and graduate research students. The interests of group members, though diverse, cluster around the general theme of environmental change, and in particular the dynamic nature of geo-ecological processes and the human dimensions of low latitude (tropical) regimes. Such regimes are amongst the least studied and therefore most poorly understood on Earth. Environmental change is occurring as a result of both non-human (natural) and human (anthropogenic) forces: the pervasiveness and primacy of anthropogenic contributions, and of the critical importance of low latitude environments, to planetary scale-changes on Earth are increasingly accepted.

Read More


Academic staff

Research Projects

 Geographically, research activities of members of TEC focus on low latitude parts of Asia, increasingly seen as the most rapidly changing part of Earth’s surface, and an important driver of global scale changes in climate, environmental quality, land cover and socio-economic conditions.  A focus on Asia takes advantage of NUS’s physical location and recognises the many contributions that researchers can make towards improving understanding of dynamic processes and the environmental consequences of rapid development, land cover transformation and climate change across the range of local to global scales. Members of the research group have spearheaded projects in the region concerned with sediment and water quality dynamics; forest hydrology and biogeochemical cycles; rainfall-runoff relationships; behaviour of extreme hydro-climatic events and their geomorphic signatures; microclimatology and urban climates; vegetation change; human-environment interactions, including environment and health; and the impact of the Indian Ocean tsunami of 2004 on coastal systems, settlements and livelihoods.  Beyond Asia, members of the group have extensive experience of environmental change research in other low latitude locations, notably eastern Africa and the Pacific Islands.

TEC researchers have access to improved Earth Science and GIS/Remote Sensing laboratories in the Department of Geography following substantial investments over the last decade.  These facilities continue to be the focus of new investment, providing improved levels of research-focused laboratory and field-based support in Geography.   TEC researchers also participate actively in numerous international research networks, groupings and projects; are members of the editorial boards of several internationally-regarded journals; and frequently host workshops and regional and international conferences.  Moreover, many members of TEC engage in crosscutting research programmes hosted in the research group – details of these can be found via the links to members of academic staff involved in TEC. 


GIS/Remote sensing/geo-techniques

  • A Singapore Historical GIS Analysis: The Transformation of Chinese Institutions (Kenneth Dean, Chinese Studies; Feng Chen-Chieh, Wang Yi-Chen; Ong Chang-Woei, Koh Khee Heong, Chinese Studies; Arthur Tay, Electrical and Computer Engineering; Lily Kong, Feng Yikang, NUS Library)
  • Unified China and divided Europe: The Causes and Consequences of Political Centralization and Fragmentation in the Pre-modern World (Sng Tuan Hwee, Economy; Feng Chen-Chieh, Wang Yi-Chen; Ko Chiu Yu, Economy)
  • Experiential Learning using Sandboxes and Augmented Reality in Natural Sciences (2015-2016) (Nawaz Muhammad, Sandeep Kundu)


Urban climatology

  • Evaluating the thermal regulation of Singapore’s urban green spaces: a multi-method investigation (2016-2018) (Winston Chow)
  • Investigating the resilience of Singapore's water supply to meteorological drought (2016-2017) (Winston Chow)
  • Creating Cooler Parks in the Future (2016-2019) (Winston Chow; Rachel Oh, Cybil Kho, National Parks Board)
  • Cooling Singapore: Urban Heat Island Mitigation (2017-2020) (Winston Chow, Matthias Roth; Peter Edwards, Gerhard Schmitt, Future Cities Lab; Leslie Norford, Singapore-MIT Alliance; Alois Knoll, TUM-CREATE)
  • Three-dimensional observation and modelling of small-scale urban climates in Singapore (2013-2016) (Winston Chow)
  • Integrated, multi-dimensional measurements of temperature, humidity and carbon dioxide in Singapore (10/2014-09/2017) (Tier1; PI Matthias Roth, Winston Chow)
  • Assessing the impact of key climate processes over Singapore (04/2016-04/2018)  (RCA with NEA; PI Matthias Roth, Andrés Simon; with collaborators in Center for Climate Research Singapore)    
  • Energy balance and carbon dioxide exchange over a residential neighbourhood (Matthias Roth; Erik Velasco, Singapore-MIT Alliance for Research and Technology)
  • Spatial and temporal variability of the urban heat island in Singapore (Matthias Roth; Reuben Li, University of Tokyo)


Hydrology/geomorphology/coastal environments

  • An ecosystem services framework for sustainable coastal management in Singapore (2014-2017) (Dan Friess)
  • Carbon cycles in large Asian rivers (2015-2018) (Lu Xi Xi)
  • Anthropogenic perturbations to carbon export and greenhouse gas evasion from Asian river systems (Ji-Hyung Park, Ewha Womans University, Korea; Lu XX; with 10 collaborators from USA, China, Cambodia, Vietnam, India, and Bangladeshi)
  • Influence of land-use change on the aquatic carbon loss from the Rajang River (Moritz Muller, Swinburne University of Technology, Kuching, Malaysia; Aazani Mujahid, UNIMAS, Kuching, Malaysia; Massimo Lupascu; Denise Muller, University of Bremen, Germany; Bradley Eyre, Southern Cross University, Lismore, Australia; Gonzalo Garrasco, NTU, Singapore; Jing Zhang, East China Normal University, Shanghai, China)
  • Surface and subsurface elemental dynamics in threatened mangroves of SE Asia (2015-2017) (Ziegler AD)
  • Reconstruction of palaeoflood histories on mainland rivers (R-109-000-174-646) (2014-2016) (Ziegler AD, RJ Wasson)
  • High-resolution late Quaternary environmental and climate change from south-eastern Australia (Chris Gouramanis; Chris Turney, UNSW; John Tibby, University of Adelaide; Peter Kershaw, Monash University).
  • Sedimentological, geochemical, ground penetrating radar, genomic and geostatistical analysis of recent storm and tsunami deposits along the western Thai coastlines (Chris Gouramanis; Adam Switzer, Federico Lauro, NTU; Kruawan Jankaew, Chulalongkorn Univeristy; Charlie Bristow, Birkbeck College, UCL).
  • Discriminating storm and tsunami deposits using sedimentology, geochemistry, micropalaeontology, ground penetrating radar and geostatistical analyses from south-east India (Chris Gouramanis; Adam Switzer, NTU; Seshachalam Srinivasalu, Anna University; Harry Jol, University of Wisconsin-Eau Claire).
  • Coastal evolution and storm history of central Vietnam (Adam Switzer, NTU; Charlie Bristow, Birkbeck College, UCL; Chris Gouramanis; Barbara Mauz, University of Liverpool; Doan Dinh Lam, VAST).


Human-nature interactions (including ecology and environments)

  • Use of carbon sequestration to finance reforestation of poor farmers’ marginal farmland: A case study of China (Claudio Delang, Hong Kong Baptist University; Lu Xi Xi; with 2 collaborators from China and Germany)
  • Impacts of Landscape Patterns on Urban Ecology and Sustainability (Wang Yi-Chen).
  • Reconciling agricultural expansion and forest conservation in the new Myanmar (01/2016-01/2019) (Webb EL, LR Carrasco, M Rao, AD Ziegler)
  • Ecological Mangrove Restoration surveys at Pulau Ubin (Dan Friess; Germaine Leng, National Parks Board; with members of the RUM Initiative)
  • Australian ostracod ecology, biogeography and geochemistry (Chris Gouramanis; Stuart Halse, Bennelongia Pty. Ltd.; Patrick De Deckker, ANU).
  • Ecosystem functioning in one of the last pristine peat forest of SE Asia (Charles Harvey, MIT, USA; Alex Cobb, SMART-MIT, Singapore; Massimo Lupascu)
  • Peat susceptibility to fires in a non-land use setting in Brunei (Charles Harvey, MIT, USA; Alex Cobb, SMART-MIT, Singapore; Massimo Lupascu)
  • Mitigation of Climate Change through Fire Management in Regional Peatswamp Forests (Catherine Yule, School of Science Tropical Medicine and Biology; Massimo Lupascu)
  • Multidisciplinary Platform, Monash University (Chris Austin, School of Science TMBMP, MUM; Stephanie Evers, Liverpool John Moores University, UK; Thomas Smith, Kings College London; Helena Varkkey, University Malaya; Faizal Parish, Kuala Lumpur; Massimo Lupascu; Claudia Czimczik, University of California, Irvine, USA)
  • A Pan-Arctic Synthesis of Carbon Emissions During the Nongrowing Season (Susan Natali, Woods Hole Research Center; Helen Genet, University of Alaska, Fairbanks; Massimo Lupascu; with the NGS Respiration PCN Working Group)


In addition, several researchers in the group also maintain webpages relating to their research programmes or do projects they are currently working on/are interested in developing further (in collaboration with other researchers, including graduate research students and research staff).  The following is a sample of these webpages:



Visiting Professors

Prof Tim Oke, University of British Columbia (Jan to Apr 2002)


Patricia Gober, Arizona State University (2 to 13 Oct 2015)

Prof Gan Thian Yew, University of Alberta, Canada (1 to 22 March 2014)

Prof Padraig Carmody, Trinity College Dublin (8 Sep to 28 Sep 2013)
James Goff, University of New South Wales  (2 Feb to 22 Feb 2013)

Dirk De Boer, University of Saskatchewan (10 Aug to 8 Sep 2012)
David Mark, State University of New York (3 to 15 February, 2012)

Anthony Brazel, Arizona State University (10 Jan to 2 Feb 2011)

Gary Brierley, University of Auckland (19 Nov to 8 Jan 2010)

Daniel Sui, Texas A&M University (25 Feb to 4 Mar 2008)
Per Christer Jansson, Royal Institute of Technology Stockholm (4 Apr to 8 May 2008)




Editorial Board

Lu, Xixi

  1. International Journal of Sediment Research, Associate Editor, (2010- present)
  1. Quaternary International
  2. Hydrological Processes
  3. Earth Surface Processes and Landforms
  4. Singapore Journal of Tropical Geography

Roth, Matthias

  1. International Journal of Climatology, Associate Editor
  1. Urban Climate
  2. Singapore Journal of Tropical Geography

Taylor, David


  1. The Holocene
  2. The Anthropocene
  3. Singapore Journal of Tropical Geography

Graduate Research

The QS World University rankings (2018) place National University Singapore (NUS) in the top 15 universities in the world and number one in Asia. In the same rankings, and for the fourth year running, the Department of Geography, NUS, is ranked in the top ten Geography programmes globally.

The Tropical Environmental Change (TEC) research group in the Department of Geography, NUS, currently comprises around 40 faculty and graduate research students whose interests focus on geo‐ecological processes and the human dimensions of changes in tropical environments. Environmental changes in the tropics are amongst the least studied on Earth, despite their global importance.

Several fully funded scholarships (fees and stipend) for up to four years are currently available in the TEC research group. Opportunities also exist to apply for additional funding to support fieldwork and laboratory costs, if relevant, to participate in international conferences and to contribute to the Department’s teaching programmes.

Graduate research students follow a semi‐structured programme, which involves a taught component in the first two years. The programme allows a PhD student to acquire and develop to a high standard both subject‐specific and transferable skills, thus enabling a student to access a broad range of future employment opportunities. For information on how to become a PhD student at one of the world’s top universities in one of the most culturally diverse cities in the world, and on enriching careers following your PhD, see:

Please note that there are two application deadlines each year: 1 November (to begin in the following August) and 15 May (to begin in the following January). For further information, please contact the Department’s graduate administrator Ms Pauline Lee.

The TEC research group is particularly interested to receive applications from suitably qualified candidates (excellent performances in bachelor’s and master’s degrees in relevant subjects) who are interested in pursuing research relating to the themes listed below. We are also happy to consider applications within the broad field of Tropical Environmental Change. Applicants are advised to consult with faculty members whose research interests most closely match their own. For further advice, including whom among the TEC faculty might be best able to help develop a proposal, please contact the TEC Chair - Associate Professor Dan Friess.

Application details are at: All applications must include a Statement of Purpose; this document places less emphasis on the “Research Proposal” and more on the ability of an applicant to write concisely and precisely. Successful applicants will then spend much of their first year as a PhD student further developing their PhD research proposal.

For further details on specific topics/themes please contact the faculty members listed:

Spatiotemporal data modelling and analysis in GIS
Associate Professor Feng Chen‐Chieh

Geographic information systems (GIS) provide an integrative platform for analyzing and understanding the spatiotemporal characteristics of our physical and built environments and the activities that take place there. Central to the success of such efforts is the ability to correctly model important events at both the technical and semantic levels. Under this general research umbrella, we are currently looking for people interested in the following research directions and topics:

(1) Three‐dimensional virtual environment
- AI or machine learning approaches to classify point cloud data and extract building model semantics
- Adaptive 3D models for rendering at multiple levels of detail
- GIS and BIM integration - Sense‐making analytics and simulation models for time‐sensitive applications

(2) Conceptual modeling of geographic features
- Understand how languages affect the conceptualizations of geographic features
- Ontologies for automatic terrain mapping
- Approaches for exploring naïve understanding of geographic features from spatial big data

(3) Historical GIS of Chinese institution in Singapore
- Approaches to handle uncertainty in historical data
- Approaches to capture and visualize spatially-explicit social interactions
- Linked open data for historical data exploration



Mangrove forest ecosystem services and conservation
Associate Professor Daniel Friess

Mangroves provide important ecosystem services and support the livelihoods of millions of people in Southeast Asia, though are in rapid decline. Research in the Mangrove Lab focuses on the geomorphological, ecological and social factors that affect mangrove stability and ecosystem service provision, using field‐based and remote sensing techniques. We are particularly interested in conservation and policy‐relevant research. Topics may include:

- quantification and modelling of mangrove ecosystem services
- mangrove deforestation, particularly novel threats such as oil palm
- policy aspects of mangrove restoration and conservation (including Payments for Ecosystem Services)

Current study locations include Singapore, Thailand, Indonesia, Philippines, Madagascar and New Caledonia. Students will be expected to work closely with our regional University and NGO partners. For more information on current projects see



High‐resolution palaeoenvironment and palaeoclimate of Southeast Asia
Assistant Professor Christos Gouramanis

The long‐term climatic history of South‐east Asia is still poorly constrained with the interaction of the Indian Ocean Dipole, Monsoon and El Niño Southern Oscillation having profound effects on drought, fires, floods and typhoons in the region and further afield. Several lacustrine and marine sites in Malaysia, Thailand, Vietnam and Indonesia have been identified as sources for sediment archives that will produce palaeoenvironmental and palaeoclimate histories. These histories will tease out how the climate systems interact and provide important climatic context for future climate variability in this region. An interested student will analyse a series of archives in very high resolution from these lacustrine systems using a multi‐proxy approach including geochemistry, sedimentology, micropalaeontology and geochronology. The ultimate aim is to derive palaeoenvironmental change histories for the region and relate these to both climate and people in the past, present and future.



Riverine sediment fluxes and carbon cycles
Professor LU Xi Xi

Riverine sediment and its associated carbon fluxes, burial and emission (or outgassing or evasion) are an important part of carbon exchange between terrestrial, oceanic and atmospheric environments (Raymond et al. "Global carbon dioxide emissions from inland waters." Nature 503.7476 (2013): 355-359) and thus must be considered in strategies to mitigate climate change (Chappell et al., The global significance of omitting soil erosion from soil organic carbon cycling schemes." Nature Climate Change, 2015). However, understanding of spatial and temporal dynamics of such exchanges is very limited for the large Asian rivers that originate from the Himalaya mountains and Tibet Plateau.

We are particularly interested in the topics listed below:
- quantification of sediment/carbon fluxes and carbon burial/outgassing from large Asian rivers
- impacts of dams construction and land use change on sediment fluxes and carbon cycles
- impacts of climate change and resultant glacial retreat or permafrost thawing on sediment/carbon fluxes in the headwater region in Tibet Plateau

On‐going study locations include Huanghe (Yellow River), Changjiang (Yangtze River), and Mekong River. Please see



Tropical peatland forest and its role in the global carbon cycle
Assistant Professor Max Lupascu

Tropical peatlands hold about 88.6 Gt C or equal to 15‐19% of the total global carbon (C) pool. The majority (84%) of these peatlands are situated in Indonesia (21 Mha), followed by Malaysia (2–2.5 Mha) (Page et al. 2011). Due to increased demand for palm oil production, pulpwood plantations and agriculture, tropical peatlands are subject to intensifying pressures, including deforestation and drainage. This practice exposes previously undecomposed organic matter to oxidation, which results in
a) peat subsidence,
b) increase in CO2 and N2O emissions, and
c) increase in peat flammability.

Within this context our lab wants to answer the following question: how land‐use change and climate change are affecting and will affect the carbon cycling of the peat swamp forest of SE Asia? What are the implications in the global carbon budget?

Possible topics of investigations: - Ecosystem functioning of peat swamp forest
- Peat accumulation/decomposition models
- Peat subsidence under different land uses
- Refining carbon stocks estimates under different land uses
- How to improve peatland restoration
- Soil ecology and biogeochemistry of burnt peat areas
- Fire disturbance on intact forest

Research methods include: - Greenhouse gases analysis through cavity ring‐spectroscopy (Picarro)
- Soil incubation
- Stable and radiocarbon isotopes (13C‐14C)
- Soil chemistry analysis
- Remote sensing

Interested students with prior training in terrestrial biogeochemistry, ecology or physical geography are encouraged to apply. Previous fieldwork experience would be beneficial. Publication in peer‐reviewed scientific journals is strongly encouraged.
For more info check



Understanding human impacts on climate caused by urban development
Professor Matthias Roth & Assistant Professor Winston Chow

PhD projects under this research theme investigate the broad question of how land‐use and land cover changes affect local climates with a particular focus on cities and the role they play in climate change. Our group uses experimental approaches (observations in the field, analysis of GIScience and Remote Sensing data, and application of numerical climate models) to study various aspects of the urban climate, including:
(i.) the development of the urban heat island (UHI) effect and its consequent impacts on exposure to thermal discomfort,
(ii.) cycling of heat, mass and carbon dioxide as well as
(iii.) fundamental flow and turbulence properties.

Our laboratory is primarily Singapore, an increasingly important hub for urban climate research in the tropics. Findings from this research are important to improve our understanding of the physical transfer processes and energy balance in the urban environment, as well as in assessing the vulnerability of urban populations towards detrimental impacts of urban climate change. Applications include the prediction of the exchanges of energy and moisture at the surface, dispersion of pollutants, cycling of atmospheric trace species that play a key role in climate change or human thermal comfort and climate sensitive urban design.

Interested students with strong science backgrounds as well as those with prior training in atmospheric sciences, climatology or physical geography are encouraged to apply. The development and completion of own research agenda, leading to scientific publications is strongly encouraged.



Reconstructing past environmental dynamics in eastern Tropical East Asia based on palaeolimnological approaches
Professor David Taylor

Tropical East Asian environments are amongst the fastest changing in the world. However, there is little well‐dated, high‐resolution evidence of past environmental changes against which current rates and magnitude can be compared. This raises questions regarding the long‐term sustainability of environmental change in the region, and the degree to which environmental resilience – or the ability of ecosystems to recover ‐ may be being exceeded.

This PhD research opportunity targets Luzon, the largest of the archipelago of islands that make up the Philippines and a particularly dynamic part of Tropical East Asia (TEA). Inhabitants of Luzon face a number of environmental hazards: the island lies across a major tropical cyclone track and is tectonically highly active, being located along a boundary between colliding plates (Eurasian to the west and Philippines to the east). Volcanic activity is also common. Luzon, along with many other parts of the Philippines, has also long been impacted by human activity, with deforestation presumably linked to the early production of food commencing at least ca. 4000 years ago and environmental pollution now widespread. In particular, the research will target up to three lakes on Luzon, all volcanic in origin. Lake sediments potentially contain a rich diversity of sources of evidence of environmental changes that have and are taking place in the air‐ and watersheds.

Three lakes have been identified as having high potential for the type of palaeolimnological research envisaged here. The lakes span around 5° of latitude on the island of Luzon and lie across a main typhoon track. All are located at relatively low altitude (<500m above mean sea level) and are thought to be relatively pristine. They also likely support conditions that are highly suitable for the accumulation and preservation of undisturbed sediments (e.g. deep water, a stratified water column for large parts of the year, strongly anaerobic benthic conditions etc.). The three lakes identified are Nalbuan in the north of the island and Bulusan in the south. Danao is located between the two. Bulusan is protected as a National Integrated Protected Area (NIPA), with the designation based on its known biodiversity value. Palaeolimnological data will be combined with existing evidence, including information from contemporary aquatic ecological studies, to provide detailed information on environmental changes in the lakes concerned and in their air‐ and watersheds during the Holocene, with a particular emphasis on the Great Acceleration of the Anthropocene. The Anthropocene is regarded as the (current) period of maximum human impact, with the Great Acceleration commencing around 60 years ago in many parts of the world.

Sediment‐based evidence used in the reconstruction of environmental conditions will include the remains of plants (diatoms, pollen, plant pigments [including those associated with toxic algal blooms]) and animals (zooplankton, Crustacea). Sediment geochemistry will provide additional information on variations in heavy metal concentrations and other toxins, such as PAHs, which can have long residence times in the environment. Spheroidal Carbonaceous Particles (SCPs), a by‐product of fossil fuel combustion in power stations, are also a proxy of variations in acidification pressures (they are linked to SO2 emissions) and have proved a useful marker for the Great Acceleration in other parts of the world.

The PhD student recruited to this project will work in collaboration with partners in the Philippines (in particular staff and research students at University Santo Tomas in Manila) and in the UK (UCL and University of Nottingham).



Spatial Ecology in Asia: Linking Patterns and Processes
Associate Professor WANG Yi‐Chen

Spatial ecology investigates the spatial patterns of the organisms and the landscape, and their ecological consequences, through the applications of GIS, remote sensing, and spatial statistical analysis. Within this research area, students interested in the research themes of:
(a) health and environment and
(b) urban ecology
are encouraged to apply.

Topics may include: - Health and environment: landscape determinants of infectious disease (foodborne, waterborne, or soil transmitted diseases)
- Impacts of land change on disease ecology
- Environmental and social determinants of disease prevalence and transmission
- Spatial analysis and modeling of disease host/vector distributions and disease risks
- Impacts of landscape patterns on urban ecology and sustainability
- Assessing the effectiveness of remote sensing images in depicting patterns of urban green space
- Developing approaches to incorporate the three‐dimensional data to better characterize the urban landscape
- Quantifying patterns and structures of urban green space and investigating their impacts on ecological processes and/or the health of human well‐beings
- Incorporating historical GIS for land change analysis and approaches to handle data quality in multi‐temporal data sets