Special report on the fourth international conference on countermeasures to urban heat island (4th IC2UHI Conference) in Singapore

Initiated by Prof. Hashem Akbari, international conference on countermeasures to urban heat island (IC2UHI Conference) was first held in Tokyo, Japan in year 2006. Subsequently, it was held in Berkeley, USA and Venice, Italy in year 2009 and 2014 respectively. After being held in temperate climate countries, the committee felt that it was timely to organize the conference in a tropical climate country where urban heat island (UHI) effect coupled with climate change has become major issues creating overheating problem.

The fourth IC2UHI Conference was held on 30–31 May and 1 June 2016 in the Stephen Riady Centre, National University of Singapore, Singapore. The conference had a theme “Fighting urban heat island (UHI ) and climate change through mitigation and adaptation ” that covered range of topics, as follows:

• Special Topic : Recent UHI and climate change research from cities in Asia Pacific and tropical countries (16 papers ).
• Relationship between UHI, urban planning and building energy consumption and comfort (57 papers).
• Anthropogenic heat and urban pollution (8 papers).
• Cooling effect of natural sources on evaporation & evapotranspiration (vegetation, lakes, rivers, ground) (13 papers).
• Simulation and analysis of UHI and its effects across scales (urban microclimate measurement, urban ventilation and modeling) (54 papers).
• Social and economic dimension: UHI economy & health and quality of life (10 papers).
• Program development, policy and evaluation of UHI mitigation and adaptation (12 papers).
• Building energy savings and air pollution from cool surface deployment (field experiments & new analysis methods) (13 papers).
• Cool materials, roof, pavement and advance materials developments & characteristics (15 papers).
• Development of performance testing standards for cool materials (3 papers).

There were four parallel sessions accommodating close to 200 presentations during the three days of the conference. The conference also saw a large numbers of participants from 26 countries with Japan and China had the highest numbers of participants.

Besides as a platform for researchers and academics share their latest research in UHI and its mitigations, this conference also aimed to be a platform for policy makers and practitioners share their efforts in mitigating the UHI effect in the cities. To achieve this objective, several keynote speakers from the Singapore government agencies who led the urban planning and design of the city state were invited to share their visions, policies and experiences. Mr. Chiu Wen Tung, Acting Director Research and Development of Urban Redevelopment Authority (URA) shared the strategies of urban planning in Singapore. It starts with development of Concept Plan, which maps out vision for Singapore in the next 40–50 years. The Concept Plan is then translated into Master Plan, a land use plan which guides the development of Singapore over the next 10–15 years and it is reviewed every five years. This Master Plan is subsequently used in the urban design plans, development coordination and land sales, including development controls. Development proposals are evaluated based on the requirements that control density of developments and indirectly facilitate air flow. Landscaping for Urban Spaces and High Rises (LUSH) program requires developers to replace greenery from the site due to development with greenery in other places within the development.

The first keynote speaker from the academic was Prof. Edward Ng, who has vast applied research projects including the development of performance-based daylight design practice note, the Air Ventilation Assessment Technical Guidelines and the Urban Climatic Maps for City Planning for Hong Kong government. Prof. Ng shared his knowledge on how to translate “urban sciences to urban planning” and “urban sciences to urban design”. The consideration of urban climatology for planning is necessary. Planners must be assisted by and work with urban climatologists when interpreting and applying urban climatic considerations. Meanwhile, from practitioner, the committee invited Dr. Ken Yeang, from TR Hamzah and Yeang architect firm. He said “even if we build the greenest buildings today, the overall mitigation become minimal …. Effective action must be at the mega scale of cities, regions & infrastructure …”. Dr. Yeang, then shared his projects different part of the world showcasing his design concepts in bringing in nature in the development and/or buildings.

The topic highlight in this conference is the “Special Topic : Recent UHI and climate change research from cities in Asia Pacific and tropical countries ”. It aimed to showcase research works from the Asia Pacific region and tropical countries around the world, which was not be the focus in the past and also to provide opportunity for participants from developing countries around the region to present their works. Ren Chao presented her team׳s work on the World Urban Database and Access Portal Tools (WUDAPT), classifying the Local Climate Zones (LCZ) of major cities in China. Up to date, the LCZ mapping work for 45 cities and several major economic regions in China has been completed. Some UHI-related study in tropical countries presented at the conference including from Bangkok, Jakarta, Nagpur, Sao Paulo and Brasilia. Pattaranan Takkanon presented her work on the effect of height-to-width (H/W) ratios of street canyon on urban intensities in six different areas of Bangkok, as representatives of medium and high densities, medium and high traffic, as well as a range for low to high surface temperatures. Kentaro Maeda et al. shared his simulation study by means of coupled Canopy Model and Building Energy Model (CM-BEM) on two types of green roofs, intensive and extensive green roofs, on an office building in Jakarta.

Topic on Simulation and Analysis of UHI still has the most number of papers presented at the conference with many have focus on multi-scale UHI simulation. Lim Tian Kuay from the National Environmental Agency (NEA), Singapore, shared the agency׳s plan to develop multi-scale urban system modeling for sustainable urban planning and design. The modeling platform, when completed, will be able to simulate from global/regional-scale, city/urban-scale and down to building-scale. Another topic on simulation that has been the interest of UHI modelers is the simulation of trees. Trees are known to have benefits in ameliorating UHI effect, through shading and evapotranspiration process. However, due the complexity of tree structures, it has been always a challenge to model it as part of computer simulation study, especially in Computational Fluid Dynamics (CFD) simulation. Jonathan Yik et al. from Institute of High Performance Computing (IHPC), Singapore, has been working on simplified tree model for CFD simulation. The team used the data obtained from ray tracing simulations of detailed tree models to derive optical properties which then is applied to a much simplified tree model constructed out of simple geometric shape. Manickathan Lento et al. presented his team׳s investigation work on the drag profile and turbulent flow field of flexible and inflexible model trees by wind tunnel experiments as their values are needed to accurately model the turbulent flow field around vegetation.

A relatively “new” topic introduced in this IC2UHI conference was the Social and economic dimension: UHI economy & health and quality of life. Several papers discussed the UHI effect in relation to human health and mortality. Prof. Hashem Akbari shared his student׳s, Zahra Jandaghian, initial research on the relationship between UHI adverse effect on air quality and human health. Prof. Mattheos Santamouris and team conducted epidemiological study to analyse the mortality of the years 2002–2012 in the Municipality of Athens, Greece, that was attributed to temperature extremes. The study confirmed that the cardiovascular and respiratory mortality of people over 65 years of age, increased by 20–35% at very low and very high temperatures.

On a softer note, in this conference, the committee decided to replace the typical conference gala dinner with networking dinner, where all participants were invited to attend it without additional fee. This dinner was held at the multi-purpose hall inside Hort Park, part of Southern Ridges that comprises Mount Faber, Telok Blangah Hill Park, Kent Ridge Park and Labrador Nature Park. The highlight of this networking dinner was the presentation of seven travel scholarships to Master and PhD students from developing countries so that they were able to come to the conference and presented their research works.

In summary, we felt that this conference was a great success especially this is the first time this conference was held in the tropical country and in Asia region. Because of this, the conference has attracted a very good participation from Asian countries specifically the researchers from South East Asia, Hong Kong, Taiwan, Southern cities of China and Japan. It is hoped that through this channel, greater interest can be generated for research of UHI in the tropical regions.