The Identification of Urban Thermal Islands based on an Environmental Approach, Case Study: Isfahan Province

Today, urbanization and environmental impacts have been revealed to everyone. Among the harmful effects of urbanization, thermal islands have been considered by politicians and researchers in the field of environmental science more than any other factor. The aim of this research is to identify the critical environmental zones of Isfahan urban thermal islands. In order to achieve this goal, the first 9 images were downloaded from Landsat 8 satellite for the warm period of the year 2013 through 2015. Then, the required pre-processing schemes, land surface temperature (LST) and normalized difference vegetation index (NDVI) were calculated. Then, the Environmental Criticality Index (ECI) was used to identify sensitive areas. The results showed that there is a sharp thermal slope between the city center and the suburbs due to the existence of a cool thermal island in the city center. The largest urban thermal islands were identified in the 6th district. Focal thermal islands and urban thermal islands strip are two types of thermal islands after the peripheries accounted for most regions in this study. The highest environmental sensitivity was in the southern part of the city (6th district of the city) and the lowest environmental sensitivity was in the center of the city (urban areas 1 to 3) were identified. In order to solve this crisis, the upcoming proposal to develop green roof vegetation organized and tailored to the indigenous climate can be considered as the best practice for thermal island mitigation.