Steve Kardinal Jusuf - My Research Publications

Integrated Urban Microclimate Assessment Method as a Sustainable Urban Development and Urban Design Tool

2011-03-09T00:32:00.001-08:00

Landscape and Urban Planning Special Issue Volume 100

Nyuk Hien WONG, Steve Kardinal JUSUF AND Chun Liang TAN

ABSTRACT
In the past decades, urban heat island (UHI) phenomenon in the city and its corresponding issues including the mitigation methods have become the main research topics in the area of urban climatology. Researchers have conducted various investigations and measurements in the urban environment. Prediction models such as impact mitigation strategies, urban air temperature predictions, improved weather forecasting and air quality forecasting have been developed as a result. With the current issue of sustainable urban development in the cities, urban planners are beginning to look into different aspects of urban climatic parameters and incorporate them as the design parameters. However, it is rather difficult for the planners to attempt to design without engaging the urban climate scientists. Presently, Geographical Information System (GIS) is a platform commonly used in various geographical related research and applications, including those relating to urban climate research, as it can be used to analyze different urban climatic parameters. Although it is, by all standards, an appropriate urban design tool, urban planners tend not to embrace this technology. This paper shall present an idea to overcome this challenge by means of developing a user friendly urban design platform that takes after GIS. This paper will also discuss the plan for advancement of the urban design tool from the current situation to the future.

Keywords: integration, urban climate research, sustainable urban development, urban design tool

http://www.scribd.com/doc/50343708/Integrated-Urban-Microclimate-Assessment-Method-as-a-Sustainable-Urban-Development-and-Urban-Design-Tool#

Evaluation of the impact of the surrounding urban morphology on building energy consumption

2010-12-06T23:38:00.000-08:00

Solar Energy 85 (2011), 57-71

Nyuk Hien Wong, Steve Kardinal Jusuf, Nedyomukti Imam Syafii, Yixing Chen, Norwin Hajadi, Haripriya Sathyanarayanan, Yamini Vidya Manickavasagam

Abstract
Empirical models of minimum (Tmin), average (Tavg) and maximum (Tmax) air temperature for Singapore estate have been developed and validated based on a long-tem field measurement. There are three major urban elements, which influence the urban temperature at the local scale. Essentially, they are buildings, greenery and pavement. Other related parameters identified for the study, such as green plot ratio (GnPR), sky view factor (SVF), surrounding building density, the wall surface area, pavement area, albedo are also evaluated to give a better understanding on the likely impact of the modified urban morphology on energy consumption. The objective of this research is to assess and to compare how the air temperature variation of urban condition can affect the building energy consumption in tropical climate of Singapore. In order to achieve this goal, a series of numerical calculation and building simulation are utilized. A total of 32 cases, considering different urban morphologies, are identified and evaluated to give better a understanding on the implication of urban forms, with the reference to the effect of varying density, height and greenery density. The results show that GnPR, which related to the present of greenery, have the most significant impact on the energy consumption by reducing the temperature by up to 2 degC. The results also strongly indicate an energy saving of 4.5% if the urban elements are addressed effectively.

Keywords: Impact; Urban morphology; Building energy consumption; Energy simulation; Singapore

http://www.scribd.com/doc/44816460/Evaluation-of-the-Impact-of-the-Surrounding-Urban-Morphology-on-Building-Energy-Consumption

STEVE can keep you cool - TODAY newspaper 19 February 2010

2010-02-24T17:04:00.002-08:00

High Time for Lower Temperature - Business Times 19 February 2010

2010-02-24T17:04:00.001-08:00

JTC and NUS jointly developed temperature prediction software - Lian He Zao Bao, 19 February 2010

2010-02-24T17:01:00.000-08:00

Study on the Microclimate Condition along Green Pedestrian Canyon in Singapore

2009-11-29T19:42:00.000-08:00

Wong Nyuk Hien and Steve Kardinal Jusuf

Architectural Science Review 53 (2010) 196-212

ABSTRACT

The research on urban canyon in the tropics is still very limited. Currently the research focus has been in the temperate climate especially in the development of urban canyon temperature prediction model. In the Singapore context, the cooling impacts of greenery in the form of parks and rooftop gardens have been well established. However, the cooling effects within the different green canyon forms have not yet been explored.

Experimental data was therefore collected in this study to examine the issues. Firstly, the microclimate condition and the thermal effects along two pedestrian canyons with different greenery and building distribution conditions were investigated. The results show that the cooling effects inside the canyons vary as a function of vegetation cover and shading effect from trees and buildings. Planting vegetation within the canyon can be an effective passive measure to improve the microclimatic condition. Secondly, the pedestrian thermal comfort was also calculated. The calculated Mean Radiant Temperature (MRT) and Physiologically Equivalent Temperature (PET) show that mature trees are able to provide thermal comfort to the pedestrian due to their ability to provide sufficient shading.

Keywords: Microclimate condition, Impact of trees, Green pedestrian canyon, Outdoor thermal comfort, Singapore

http://www.scribd.com/doc/33126543/Study-on-the-Micro-Climate-Condition-Along-Green-Pedestrian-Canyon-in-Singapore

STEVE TOOL: A WEB APPLICATION OF SINGAPORE AIR TEMPERATURE PREDICTION MODEL

2009-11-29T19:41:00.000-08:00

Steve Kardinal Jusuf and Wong Nyuk Hien

Presented in iNTA-SEGA 2009 - Bridging Innovation, Technology and Tradition, 2-4 December 2009, Bangkok, Thailand

RECEIVED THE BEST PAPER AWARD
ACCEPTED FOR PUBLICATION in Journal of Green Building

ABSTRACT

Empirical models of minimum (Tmin), average (Tavg) and maximum (Tmax) air temperature for Singapore estate have been developed and validated. The independent variables that were used in the models are daily minimum (Ref Tmin), average (Ref Tavg) and maximum (Ref Tmax) temperature at reference point, average of daily solar radiation (SOLAR), percentage of pavement area over R 50m surface area (PAVE), average height to building area ratio (HBDG), total wall surface area (WALL), Green Plot Ratio (GnPR), sky view factor (SVF) and average surface albedo (ALB).

However, these models are far too complicated for educated non-scientists, such as urban planners. At the end, these models are often kept in the shelves until the scientists are engaged to do the assessment.

The Screening Tool for Estate Environment Evaluation (STEVE) was developed with the motivation as mentioned above, which is to bridge between research findings, especially the air temperature prediction models and the urban planners. STEVE is a web application that is specific to an estate and it calculates the Tmin, Tavg and Tmax of the point of interest for the existing condition and future condition (proposed master plan) of the estate. This paper describes the STEVE tool and some examples of its application on a Singapore green estate.

Keywords: STEVE tool, web application, Singapore, air temperature prediction model.

INFLUENCE OF WATER FEATURE ON TEMPERATURE CONDITION IN HOT HUMID CLIMATE

2009-11-29T19:29:00.000-08:00

Steve Kardinal Jusuf, Wong Nyuk Hien and Nedyomukti Imam Syafii

Presented in iNTA-SEGA 2009 - Bridging Innovation, Technology and Tradition, 2-4 December 2009, Bangkok, Thailand

ABSTRACT

Water features, in urban areas, have a good effect on the micro-climate of surrounding with its cooling effect from the evaporative process. Thus, evaporative cooling maybe is one of the most efficient ways of passive cooling for building and urban spaces.

This paper describes the result of field measurement on the micro-climate around a water-wall at One-North Park, Singapore. Continuous measurements were conducted at eight points near this water-wall and one reference point outside the area for two month. Two typical days between 11th March 2008 and 23rd June 2008 represent clear sunny day and rainy day was chosen to get more understanding on the performance of evaporative cooling from the Water-wall at One-North, Park.

The cooling benefits from the Water-wall are shown not only from the cooler air temperature near the Water-wall but also to the lower air temperature in the nearby environment. The presence of water-wall at One-North Park obviously improves the thermal environment in hot sunny day by cooling the air. But the cooling effect is limited to its surrounding. The field measurement found that on 10am and 1pm, when the Water-wall is operated, the temperature drop was relative to the distance from the water-wall. The nearer to the water-wall, the cooler the ambient air temperature will be. The air temperature near the Water-wall were found 1.7-1.8K cooler than the reference point. These result shows that the temperature drop is induced by evaporation of water from the Water-wall. However, the apparent relative humidity profiles reveal that the water-wall tends to moisten the air through transfer of moisture from the evaporation process, which may influence the human outdoor thermal comfort in some extent.

Keywords: influence, water wall, air temperature, hot humid climate, Singapore.

Development of empirical models for an estate level air temperature prediction in Singapore

2009-09-16T17:41:00.000-07:00

Steve Kardinal Jusuf and Wong Nyuk Hien

Second International Conference on Countermeasures to Urban Heat Islands (SICCUHI)
21-23 September 2009 in Berkeley, California.
Environmental Energy Technologies Department
E.O. Lawrence Berkeley National Laboratory

ABSTRACT

Urban heat island (UHI) phenomenon has become a common problem in many major cities worldwide including Singapore. As a small island state, it is very important for Singapore to carefully plan its urban development. However, urban planners have no assessment tool to evaluate their planning impacts on the environment, especially the impact on air temperature due to the change of land use. This paper discusses the development of an empirical model for air temperature prediction to evaluate the impact of estate development by means of Geographical Information System (GIS).

Empirical models of minimum (Tmin), average (Tavg) and maximum (Tmax) air temperature for Singapore estate have been developed and validated, based on the long-term field measurement between the period of September 2005 and March 2008. The independent variables that were used in the models are daily minimum (Tmin-r), average (Tavg-r) and maximum (Tmax-r) temperature at reference point, average of daily solar radiation (SOLAR), percentage of pavement area over radius 50m surface area (PAVE), average height to building area ratio (HBDG), total wall surface area (WALL), Green Plot Ratio (GnPR), sky view factor (SVF) and average surface albedo (ALB).

Sensitivity analyses were carried out to observe the dependence of the air temperature due to the variations of each variable. An ideal type of urban canyon was used to simplify the variation of building, pavement and greenery distributions. The sensitivity analyses were carried out by varying some of the following important parameters: the greenery density (GnPR), which may affect the SVF; the building height, which affects the SVF, WALL and HBDG values; and canyon width, which affects the SVF, PAVE and HBDG values.

The Screening Tool for Estate Environment Evaluation (STEVE) was developed with the motivation to bridge between research findings, especially the air temperature prediction models and the urban planners.

Full paper:
http://heatisland2009.lbl.gov/docs/221410-jusuf-doc.pdf

Air temperature distribution and the influence of sky view factor in a green Singapore estate

2009-06-23T19:51:00.000-07:00

Wong Nyuk Hien¹ and Steve Kardinal Jusuf²

Accepted for publication in Journal of Urban Planning and Development

Abstract

This paper investigates, firstly, the influence of vegetations to the air temperature distribution and secondly, the correlation between air temperature and Sky View Factor (SVF) to understand whether the trees have adverse impact especially to the nighttime air temperature since trees reduce the SVF values. Air temperature and SVF measurements were conducted in a green Singapore estate, One-North, on 1^st November 2007 – 31^st March 2008. The field measurement results show that daytime air temperature difference between dense greenery area and less greenery area is 2.4K and the nighttime air temperature difference is 1.1K. The temperature maps study provides a clear picture on the air temperature distribution across the One-North estate and concludes that parks or clusters of trees are able to maintain both daytime and nighttime air temperature at a cool level. Statistical analysis was conducted to analyze the correlation between air temperature and SVF. During daytime, there is a significant and good correlation between air temperature and SVF. The higher the SVF, the higher is the air temperature. Trees reduce the sky openness and provide shading to the environment. At nighttime, there is a weak correlation between air temperature and SVF. Thus, there is no adverse impact, i.e. reduction of nighttime net long-wave loss, due to the reduction of SVF by trees.

Keywords: air temperature distribution, Sky View Factor (SVF), correlation analysis, green Singapore estate, tropical climate.

An Assessment Method for Existing Greenery Conditions in a University Campus

2008-04-18T09:47:00.001-07:00

Wong Nyuk Hien and Steve Kardinal Jusuf†

Published in: Architectural Science Review 2008, 51 (3), 212-220

ABSTRACT:

It is widely known that greenery has positive impacts to the environment. It is necessary to consider greenery as an important element in any contemporary urban planning. However, planners, estate managers and property managers are not able to asses existing greenery conditions in terms of quantitative data in order to achieve their goals in maintaining or improving the greenery condition. Thus, it is impossible to set a framework or plan to improve the environmental quality. The objective of this research is to develop a framework for planners to evaluate and to improve the greenery conditions in planning the urban environment.

Keywords: GIS, Greenery mapping framework, Greenery condition assessment, Planning, Urban environments

STUDY OF ROOF GARDENS IN NUS

2008-04-18T09:45:00.000-07:00

Wong Nyuk Hien, Lin Huimin, Nedyomukti* & Steve Kardinal Jusuf

2nd Building Research Student Network Symposium, National University of Singapore, Singapore.

28 March 2007

ABSTRACT:
Singapore has undergone rapid urbanization. Study shows that the huge concentration of thermal mass (building) contributes to environmental problems such as the Urban Heat Island (UHI) Effect. Heat accumulated within the urban landscape during the day is released at night resulting in higher night temperatures than normal. As the temperature in an urban area rises, more cooling energy is needed to maintain comfort levels in building structures. In addition, the UHI effect is compounded by air pollution, which reduces night-time terrestrial radiation, and by the low humidity which results from the lack of vegetation. A heat island is developed during calm conditions; winds disperse heat.

The object study of this research is inside the premises of National University of Singapore (NUS). With the introduction of new buildings to NUS Master Plan 2005, it might lead to the development of UHI. Urban greenery, such as planting of grass, trees, and shrubs could minimize the impact of the UHI effect. The potential of roof gardens within the campus was quantified and studied to further improve the urban greenery. The aim of this research seeks to study the way greenery helps in mitigating the UHI effect and determine the direct and indirect effects of the two types of rooftop garden (intensive type and extensive type).

Keywords: urban greenery, roof garden, NUS

STUDY OF ENVIRONMENTAL WIND PROFILE ON NEW UNIVERSITY TOWN @ WARREN

2008-04-18T09:42:00.000-07:00

Wong Nyuk Hien, Goh Siew Ling, Steve Kardinal Jusuf* & Nedyomukti Imam Syafii

2nd Building Research Student Network Symposium, National University of Singapore, Singapore.

28 March 2007

ABSTRACT:
This research presents the adoption of wind tunnel modeling to study the environmental wind profile to enhance the performance of natural ventilation on New University Town @ Warren. Wind tunnel experiments were conducted with the use of scaled model to determine the natural ventilation performance in terms of wind velocity. The regions with low wind velocity were identified and examined.

The study also explored the impact of variations of the design parameters, which classified into four divisions, namely, openings of buildings, height of buildings, orientation of greenery and spacing between presences of greenery on environmental wind conditions. A total of eleven stages of experiments were performed in this study. The results indicated that the values of wind velocity were significantly affected by the variation of design parameters. Openings and heights of buildings in relation to prevailing wind direction can notably enhance the wind velocity. The presence of greenery in the prevailing wind direction influences the magnitude of wind velocity by producing shielding effect, which can be proven to serve as an effective windbreak. Furthermore, tree spacing played a part in modifying the wind velocity. As trees spacing increased, the values of wind velocity increased.

Keywords: wind profile, wind tunnel study, New University Town @ Warren

GIS-Based Greenery Evaluation on Campus Master Plan

2007-07-23T02:30:00.000-07:00

Wong Nyuk Hien and Steve Kardinal Jusuf
Published in: Landscape and Urban Planning Volume 84, Issue 2, 6 February 2008, Pages 166-182
Abstract:

In the previous study, it was found that urban heat island intensity in National University of Singapore (NUS) campus as high as 4oC at around 13:00. It is also concluded that the presence of dense greenery in NUS environment is very important in keeping low ambient temperature.

National University of Singapore has announced its new master plan in 2005, entitled NUS Master Plan 2005. Many new buildings will be built and in some areas existing greenery will be removed. Geographical Information System (GIS) was use to evaluate the greenery condition. It was found that the greenery rate of NUS Master Plan 2005 will drop by about 3% from 55.10% of NUS current condition to 52.31%. In order to have a sustainable environment, the greenery condition should be at least maintain at the same rate or even make it better.

For this purpose, potential of increasing greenery area by rooftop greenery application was also done. The target is to maintain the green rate of different zones at the same rate with current condition. In total, there will be more than 56% new buildings in NUS Master Plan 2005. Therefore, there is a good opportunity to plan and introduce the rooftop greenery or vertical greenery since in the early design stage

The ENVI-Met simulation predicts that the ambient temperature in NUS environment will increase about 1oC when NUS Master Plan 2005 is completed. It is due to the reduction of greenery rate.

Keywords: NUS Campus, GIS, master plan evaluation, potential of rooftop greenery, ENVI-Met simulation, temperature prediction.

The influence of land use on the urban heat island in Singapore

2007-06-04T04:20:00.000-07:00

Published in Habitat International 31 (2007) 232–242

Steve Kardinal Jusuf, N.H. Wong, Emlyn Hagen, Roni Anggoro, Yan Hong

Abstract:

The urban air temperature is gradually rising in all cities in the world. One of the possible causes is the drastic reduction in the greenery area in cities. It means that land use planning becomes critical in determining the environment quality. This study tries to investigate and identify land use types which have the most influence to the increase of ambient temperature in Singapore. The main tools are remote sensing data and geographical information system (GIS) to obtain a macro view of Singapore and carry out comprehensive analysis at the same time. The data were analyzed by utilizing both qualitative and quantitative methods.
Both the qualitative and quantitative analysis results show that the land usage will influence urban temperature. In the daytime, the order of surface temperature in different land use types is industrial, commercial, airport, residential, and park respectively. However, during the night time, the order is commercial, residential, park, industrial, and airport. Therefore, with appropriate land use planning, the urban heat island (UHI) could be mitigated.

Keywords:
Influence; Land use; Urban heat island; Temperature; Singapore; GIS; Remote sensing

Study on Effect of Greenery in Campus Area

2007-04-17T02:36:00.000-07:00

PLEA2006 - The 23rd Conference on Passive and Low Energy Architecture, Geneva, Switzerland, 6-8 September 2006

Steve Kardinal Jusuf, Wong Nyuk Hien, Aung Aung La Win, Htun Kyaw Thu, To Satya Negara, Wu Xuchao

ABSTRACT

Urban environment quality becomes worsen in every year. There is a fact that the urban air temperature is gradually raising in all cities and some effective measures are needed to mitigate it. Planting of vegetation is one of the main strategies to mitigate the Urban Heat Island (UHI) effect. Large urban parks can extend the positive effects to the surrounding built environment. National University of Singapore (NUS) complex can be considered as a “city” in a smaller scale. The greenery area along Kent Ridge Road seems like the “rural” area, with a cooler ambient temperature. Some methodologies were employed in this study, such as field measurement and computer simulations. Field measurement was used to get the real temperature distribution across the campus and finally, computer simulation was used to predict some scenarios of different conditions.

Visit: http://www.unige.ch/formcont/plea2006/geneva.html
Download: www.unige.ch/cuepe/html/plea2006/Vol1/PLEA2006_PAPER552.pdf

Environmental study of the impact of greenery in an institutional

2007-04-17T02:29:00.000-07:00

Published in: Building and Environment 42 (2007) 2949–2970

N.H. Wong, Steve Kardinal Jusuf, Aung Aung La Win, Htun Kyaw Thu, To Syatia Negara, Wu Xuchao

ABSTRACTS

Urban environment quality is worsening every year. It is a fact that the urban air temperature is gradually rising in all cities and some effective measures are needed to mitigate it. Planting of vegetation is one of the main strategies to mitigate the urban heat island (UHI) effect. Large urban parks can extend positive effects to the surrounding built environment. National University of Singapore (NUS) complex can be considered as a ‘‘city’’ on a smaller scale. The greenery along Kent Ridge Road seems like a ‘‘rural’’ area, with a cooler ambient temperature. Some methodologies were employed in this study, such as satellite image, field measurement and computer simulations. The satellite image was used to identify the ‘‘hot’’ and ‘‘cool’’ spots in NUS environment. Field measurement was used to get the real temperature distribution across the campus and finally, computer simulation was used to predict some scenarios of different conditions. The result shows that buildings near or surrounded by greenery have lower ambient temperature than the ones away from the greenery and it is an effective way to lower the ambient temperature. The TAS simulation results also show that a rooftop garden has the potential of cooling energy savings for NUS buildings.