Strategies for Mitigating Urban Heat Island Effects in Cities: Case of Shiraz City Center

ABSTRACT: In the late years, urban heat island became one of the important problems generally in big cities as a part of climate changes and is a sort of reflection of global warming in local scale. As an outcome of global warming, urban heat island has negative effects on public health, quality of life and energy consumption. Urban heat island is temperature difference between urban and rural areas. This difference occurs due to the increase in population and urbanization process of the cities with the increase of the asphalt and built –up surfaces and accordingly decreasing the green spaces and evaporation surfaces. Not only the higher population, but also the increase in the industrial and commercial uses and dense vehicular traffic also affect the intensity of urban heat island in the city centers. According to the literature review, there are two main factors that increase the urban heat island in cities. These are city parameters and meteorological parameters. Consequently, intensity of urban heat island shows difference in each city according to the physical, morphological characteristics such as location, size, and density of their built-up areas, land uses, population and air pollution together with climatically characteristics. Today, Shiraz city, which is one of the biggest cities of Iran after Tehran, is under the pressure of rapid urbanization and population increase. Thus, the main aim of this study is to determine the impact of the factors that increase the intensity of urban heat island in Shiraz city center. Based on the main aim, the thesis has been organized as four chapters. In the first chapter, introductory part is given, and then in the second chapter the urban heat island, its types, causes and mitigation strategies has been reviewed. Consequently, in the third chapter the urban heat island in Shiraz city center is analyzed based on selected four districts around it. These four districts are selected due to having higher population size, building density, industrial uses and less green surfaces. In the last section conclusion and recommendations are given. As Shiraz developed rapidly, hard surfaces replaced with green ones. These hard surfaces, industrial and commercial uses, dense traffic and high population size in the city produce high amount of heat especially in the newly developed districts around the main center. In order to reduce the intensity of urban heat island in Shiraz, strategies for building and urban scales are developed based on the literature review. These strategies are using more green elements, albedo materials in the city and on the building’s vertical and horizontal sections. Keywords: Urban heat island, city parameters, density, urban geometry, Shiraz. ……………………………………………………………………………………………………………………………………………………………………………………………………………………