12th EMS Annual Meeting & 9th European Conference on Applied Climatology (ECAC), 2012, Poland

Simulation of Urban Heat Island Effects on the Microclimate: Using ENVI-met Model

Parisa Shahmohamadi, Ulrich Cubasch, Sahar Sodoudi

Institut für Meteorologie, Freie Universität Berlin, Germany

Abstract

This paper used the tree-dimensional microclimate model ENVI-met 4.0 which prognosticates the microclimate changes within urban environments to simulate the UHI intensity in 6 urban district of Tehran metropolitan area. The variables used in this study are higher albedo materials and vegetation cover. Three different scenarios have been defined including: 1. covering horizontal and vertical surfaces with higher albedo materials; 2. covering vertical and horizontal surfaces with vegetation covers and 3. covering vertical and horizontal surfaces with vegetation covers and high albedo material altogether. To observe the effect of each single and both variables on mitigating urban heat island in an urban area. The simulations, which run in a hot summer day for 24 hours, are compared and the results are discussed.

Key Words: ENVI-met, High Albedo Material, Vegetation Cover, Urban Heat Island.

Eighth International Conference on Urban Climate 2012, Dublin, Ireland

The Simulation of “Natural Ventilator of the City” Model by Using ENVI-met to Mitigate the Effect of Urban Heat Island in Tehran Metropolitan Area

Parisa Shahmohamadi¹, Ulrich Cubasch¹, Sahar Sodoudi¹, A.I. Che-Ani²

¹ Institut für Meteorologie, Freie Universität Berlin, Germany

² Department of Architecture, Faculty of Engineering and Built Environment,

Universiti Kebangsaan Malaysia, Selangor, Malaysia

Abstract

Natural Ventilator of the City (NVC) model has been recommended by this paper to mitigate the UHI intensity in Tehran metropolitan area. The main aim of this model is to achieve ideal condition with zero effects of UHI. In order to achieve this condition, hypothesis has been considered which if the half of 6 urban district of Tehran covers with vegetation covers and high albedo materials, it could be approached to this condition. 6 urban district, as a central district of Tehran, is one of the polluted areas which plays an important role on formation of UHI. Providing different kinds of greenery such as balcony gardens, green roofs and vertical and horizontal landscape in barren and urban lands along with using higher albedo materials can convert 6 urban district into the central ventilator. In this way, providing this natural ventilator in 6 urban district can affect the surrounding areas and mitigate the UHI intensity in whole part of the metropolitan area. Therefore, in order to prove whether the ideal condition is achievable or not, simulation of NVC model by using the micro scale climate model ENVI-met has been done. The result will be presented and discussed.

Key Words: ENVI-met, Natural Ventilator of the City Model, Urban Heat Island. 

UEP 2012 Conference (Creating Healthy, Liveable Cities)- Amsterdam, Netherlands

Natural Ventilator of the City: a Model for Alleviating Urban Heat Island

Parisa Shahmohamadi¹, Ulrich Cubasch¹, Sahar Sodoudi¹, A.I. Che-Ani²

¹ Institut für Meteorologie, Freie Universität Berlin, Germany

² Department of Architecture, Faculty of Engineering and Built Environment,

Universiti Kebangsaan Malaysia, Selangor, Malaysia

Abstract

The present paper deals with the dependence of alleviating urban heat island (UHI) on the design of an appropriate model. The model called “Natural Ventilator of the City”, recommended by this paper, has two different components including: 1) meteorological and urban structure factors which with their interactions form UHI over the urban areas; 2) vegetation covers and high albedo materials which contribute to mitigate the produced UHI. Compiling the key components into model is meaningful in promoting the passive climate control brought by vegetation covers and high albedo materials in an urban area. The interactions among the key components and the way of contribution of variables to alleviate the UHI effects are presented in the model. This study has chosen a district of Tehran as a case study. In order to test the model three approaches are presented, showing the results of UHI measurement using satellite image, UHI modeling using spatial analyses based on ArcGIS and urban climate simulations using three dimensional microclimate model ENVI-met which prognosticates the microclimate changes within urban environments.

Key Words: ENVI-met, High Albedo Material, “Natural Ventilator of the City” Model, Vegetation Cover, Urban Heat Island.

Sciencedirect

Healthy Environment: The Need to Mitigate Urban Heat Island Effects on Human Health
 

P. Shahmohamadi1¹, A.I. Che-Ani1¹, I. Etessam², K.N.A. Maulud³, N.M. Tawil¹

¹Department of Architecture, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia

²Department of Architecture and Urban Design, Faculty of Fine Art, Tehran University, Iran

³Department of Civil and Structural Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia 

Abstract

This paper is focused on understanding the most important factors of UHI formation and their effects on urban population health with an emphasis on the considerable growth of both population and rapid urbanization of Tehran, Iran. To achieve this aim, this paper explores literally a conceptual framework about the relationship between UHI and human health. Then, it suggests three important strategies to minimise the impact of UHI on human health: achieving appropriate transportation for mitigating air pollution, providing appropriate landscape, increasing the albedo of building materials.

Keywords: Albedo Materials; Healthy Environment; Horizontal Landscape; Human Health; Vertical Landscape; Urban Heat Island

See web site:  http://www.sciencedirect.com/science/article/pii/S1877705811029481

WSEAS TRANSACTIONS on ENVIRONMENT and DEVELOPMENT

The Link between Urbanization and Climatic Factors: A Concept on Formation of Urban Heat Island

 

P. SHAHMOHAMADI, A.I. CHE-ANI, N.A.G. ABDULLAH,
M.M. TAHIR, K.N.A. MAULUD, M.F.I. MOHD-NOR
Faculty of Engineering and Built Environment, UKM

 

Increasing the number of population, pollutions, urban expansion and many other kinds of urbanization factors in metropolitan areas are affected climatic factors and vice versa. In fact, there is a correlation between these two factors in general. This paper put forward the conceptual model and two hypotheses. In order to test the model, UHI mapping has been carried out in Tehran as a case study. The investigation has been done at macro-level to get surface temperature. The methodology employed is to use satellite image with a thermal band (obtained on 18 July 2000). To map out the UHI, mapping of LST and NDVI were necessary and then overlaid them and extracted maximum temperature value for both urban and rural areas. The results show that the maximum urban and rural temperature values are 39°C and 27°C respectively.  Therefore, daytime Tehran surface UHI shows 12ºC of difference between urban and rural areas which is quite strong. Analyzing the data specified that the urbanization factors have direct impact on increasing the UHI intensity in Tehran metropolitan area. 

Key-Words: - Climatic Factors, Environmental Challenge, Tehran, Urban, Urban Heat Island, Urbanization Factors

The 2nd International Building Control Conference

Healthy Environment: The Need to Mitigate Urban Heat Island Effects on Human Health

P. Shahmohamadi1¹, A.I. Che-Ani1¹, I. Etessam², K.N.A. Maulud³, N.M. Tawil¹

¹Department of Architecture, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia

²Department of Architecture and Urban Design, Faculty of Fine Art, Tehran University, Iran

³Department of Civil and Structural Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia

Abstract

Climate changes such as changes in temperature and precipitation, sea level, fisheries, agriculture, natural ecosystems, and air quality will all directly or indirectly affect human morbidity (illness) or mortality. One of the great challenges facing our current generation of scientists and engineers is how to protect urban population from health stress associated with summertime heat. As heat-waves are likely to increase in frequency because of global climate change, the most effective interventions, measures and policies to protect the health need to be developed and evaluated. Therefore, this paper is focused on understanding the most important factors of UHI formation and their effects on urban population health with an emphasis on the considerable growth of both population and rapid urbanization of Tehran, Iran. To achieve this aim, this paper explores literally a conceptual framework about the relationship between UHI and human health. Then, it suggests three important strategies to minimize the impact of UHI on human health: achieving appropriate transportation for mitigating air pollution, providing appropriate landscape, and increasing the albedo of building materials.

Keywords: building material, healthy environment, human health, urban heat island, urban landscape

Achieving Energy Consumption Balance in Kuala Lumpur Shophouses by Mitigating Urban Heat Island Effects: Focusing on Anthropogenic Heat Factor

P. Shahmohamadi, A.I. Che-Ani, K.N.A. Maulud, N.M. Tawil, N.A.G. Abdullah

Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia

shahmohamady@hotmail.com, adiirfan@gmail.com

ABSTRACT

Production of anthropogenic heat and using energy for cooling systems, lighting and etc. led to have serious impacts on the thermal environmental quality such as quality of the air, increase in temperature, energy consumption and finally the formation of UHI. Shophouses represent important land uses in Kuala Lumpur since many years ago, which influence the resulting thermal environment including the formation of urban heat island (UHI). This paper investigates the impact of anthropogenic heat on formation of urban heat island and increasing energy consumption. It explores literally the conceptual framework of confliction between anthropogenic heat and urban structure, which produce UHI intensity and affected energy consumption balance. It is then discussed how these two factors can be affected and gives implication to the city and then, focuses on whether actions should be taken for balancing adaptation and mitigation UHI effects. It will be concluded by making the important strategies to minimize the impact of UHI on energy consumption.

Key Words: Energy Consumption Balance, Kuala Lumpur, Shophouses, Urban Heat Island.