Investigating the relationship between urban growth pattern and urban heat islands: the case of Istanbul, Turkey

This study examines the interrelationship between land use, urban growth patterns, and the urban heat island effect in Istanbul, Turkey, utilising Landsat images spanning the period from 1990 to 2018. The land surface temperatures are derived from Landsat images, and the urban growth patterns are obtained using the Corine Land Cover and Global Human Settlement databases. Urban growth patterns are classified into four categories: high-rise high-density, high-rise low-density, low-rise high-density, and low-rise low-density. It is observed that the urban built-up areas in Istanbul have more than doubled during the study period, while the agricultural and forest areas have undergone a significant decrease. In consequence, there has been a notable increase in land surface temperatures (LST). The findings of the study indicate that artificial surfaces, particularly continuous urban fabric, industrial and commercial units, and airports, have exhibited the highest LST over time. A statistical analysis reveals a relationship between the growth pattern and surface temperature changes. The development patterns of high-rise low-density and low-rise low-density do not significantly contribute to the formation of urban heat islands. In contrast, high-rise high-density development and low-rise high-density development exert a pronounced influence on the formation of urban heat islands. Furthermore, a negative correlation was observed between vegetation coverage and LST, whereas a positive correlation was noted between building density and imperviousness and LST. The urban heat island effect in Istanbul, a major global metropolitan area with a population of approximately 16 million, is exhibiting a continuous increase due to the dynamics of urban growth. The findings of this study can inform the formulation of urban growth strategies for the forthcoming years, thereby facilitating thermal comfort.