This paper investigates the impact of anthropogenic heat on formation of urban heat island (UHI) and also determines which factors can directly affect energy use in the city. It explores literally the conceptual framework of confliction between anthropogenic heat and urban structure, which produced UHI intensity and affected energy consumption balance. It then discusses 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 of UHI effects. It will be concluded by making the three important strategies to minimise the impact of UHI on energy consumption: landscaping, using albedo materials on external surfaces of buildings and urban areas, and promoting natural ventilation.

Cities demonstrate higher nocturnal temperatures than surrounding rural areas, which is called “urban heat island” (UHI) effect. Climate change projections also indicate increase in the frequency and intensity of heat waves, which will intensify the UHI effect. As megacity Tehran is affected by severe heatwaves in summer, this study investigates its UHI characteristics and suggests some feasible mitigation strategies in order to reduce the air temperature and save energy. Temperature monitoring in Tehran shows clear evidence of the occurrence of the UHI effect, with a peak in July, where the urban area is circa 6 K warmer than the surrounding areas. The mobile measurements show a park cool island of 6-7 K in 2 central parks, which is also confirmed by satellite images. The effectiveness of three UHI mitigation strategies high albedo material (HAM), greenery on the surface and on the roofs (VEG), and a combination of them (HYBRID) has been studied using simulation with the microscale model ENVI-met. All three strategies show higher cooling effect in the daytime. The average nocturnal cooling effect of VEG and HYBRID (0.92, 1.10 K) is much higher than HAM (0.16 K), although high-density trees show a negative effect on nocturnal cooling.

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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 stressors 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 urban heat island (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, increasing the albedo of building materials. Keywords: appropriate landscape, appropriate material, appropriate transportation, human health, natural ventilation, urban heat island. INTRODUCTION 1Climate change is a global phenomenon that leaves no part of the world untouched. Everywhere, changes in climate are having observable impacts on both natural and human systems -water resources, ecosystems, food and forest products, coastal systems, industry, settlements and societies, and human health, involving significant social, economic and environmental consequences [1].Climate change presents significant challenges in efforts to maintain and improve the health and well-being of people living around the world. Many of the environmental hazards exert a direct or indirect effect on the health and well-being of urban dwellers. One of the most important hazards which impact on health and quality of life is 'urban heat island'. Urban heat island (UHI) can directly affect health because high temperatures place an added stress on human physiology. UHI will have wide-ranging impacts on society and the infrastructure that support civilization. It could impact not only agricultural and human health, but also patterns of human settlement, energy use, transportation, industry, environmental quality, and other aspect of infrastructure that affect our quality of life [2].According to the above perspective it becomes increasingly important to apply heat island mitigation strategies in order to protect human health from health stressors associated with summer time heat.Thus, this paper investigates that which factors cause UHI formation, especially in Tehran metropolitan, and then by recognizing some factors which have more effects on health, suggests some solutions from urban design perspective in order to have healthy environment.