URBAN SPRAWL AND CLIMATIC CHANGES IN TEHRAN
*1Gh. R. Roshan, 2S. Zanganeh Shahraki, 3D. Sauri, 4R. Borna 1 Faculty of Geography, University of Tehran, Tehran, Iran Geography and Urban Planning Department, University of Tehran, Tehran, Iran 3 Department of Geography, Universitat Autonoma de Barcelona, Bellaterra, Spain 4 Islamic Azad University, Branch of Ahvaz, Ahvaz, Iran 2
Downloaded from http://journals.tums.ac.ir/ on Saturday, October 13, 2012
Received 7 June 2009; revised 10 November 2009; accepted 20 December 2009
Urban sprawl beginning in the developed countries around 1950 is currently experienced in almost all countries.
Many studies on the effects of urban sprawl indicate the emergence of harmful effects of this phenomenon. One of the most important environmental effects is the changes in climate. The purpose of this research was to identify the relation between urban sprawl components of Tehran with changes in climate variables. To this end, two data sets have been used to study the relation between these elements and components. The first data set included climatic elements such as rainfall, temperature, the percent of relative humidity and the percent of calm wind, as well as its mean speed for a period of 54 years (1953-2006). The second set of data was formed by components relevant to urban sprawl such as city area, private cars per capita, population density and number of urban population. Pearson correlation and multiple regression methods have been applied to compare and identify the relation between climatic components with urban sprawl indices. Results of correlation indicate that among the 5 aforementioned climatic components, annual rainfall and the mean of wind speed do not appear to have significant relation with sprawl, but the oscillations in percent of relative humidity and percent of calm wind seem to have a significant relation with Tehran sprawl. Consequently and using multivariate regression, it was concluded that the most important factor in the increasing temperature of Tehran, is the number of cars; the most important factor in increasing the percent of relative humidity is the area of Tehran, whereas the increase of the percent of calm wind may be attributed to the increase of population. Key words: Urban Sprawl, Climate Change, Metropolis, Population Density, Tehran
Today, the relationships between human societies and their natural environment has been strongly affected by urbanization and urban development. Cities can be considered as ecological units and studied within the framework of a data-retrieval system. That is, to meet various needs of citizens, the city needs inevitable to provide massive data in key inputs, the most important of which are energy, food and water. Considering an increasing urban population, the result of applying such data is to obtain retrievals in the form of environmental effects such as climatic change, water pollution, air pollution, noise pollution, thermal *Corresponding author: E-mail: firstname.lastname@example.org Tel: +98 917 35 03 05
pollution and changes in the water cycle system due to waste and other impacts (Tavallaie, 1994; Shakoor et al., 2008; Golmohammadi et al., 2009; Makhelouf, 2009; Mohammadi, 2009). One of the most important phenomena linked to urbanism and urbanization which could alter the relations between humans and the environment and that is endowed with great harmful and destructive effects, is urban sprawl. Therefore, in the recent decades, urban sprawl is considered as one of the most challengeable subjects. This form which is now seen not only in the developed countries but also in the developing countries, has great undesirable socioeconomic and environmental effects such as air pollution
Gh. Roshan et al., uRbaN SpRawl aNd clImatIc ...
(Pourahmad et al., 2007), degradation or pollution of soil resources...