The role of land use changes on the formation and spatial changes of thermal islands – A case study in Ahvaz city, Iran

Abstract

In this study, 7 images of OLI and EMT sensors of Landsat 7 and 8 satellites and multi-time images of TM sensor satellite 5 have been used. These images cover the period from 1987 to 2018 (31-year period); after applying processing to satellite imagery, land use layers were prepared by supervised classification method. Then, using the thermal equations and the center algorithm, the similarity of the surface temperature of the earth for the periods of 1978, 2000, and 2018 was calculated for the study area in four stages. Results indicate that barren lands in 1987 had the largest area with 437 km and the use of irrigated land had the least area with. Studies have also shown that from 2000 to 2018, due to the increase in urban population and migration to this city and the expansion of housing construction, residential use has gradually increased to an area of 446 and the amount of land use in barren lands has decreased to 431 square kilometers. Survey of temperature with temperature changes showed that in 1987, the temperature in barren land uses reached a maximum temperature of 48 outside the suburbs, and from 2000 to 2018, land use in the northwest and west of the metropolis reached 56 to 70. Examination of the results shows that during the study year, due to population growth and the growing trend of residential use in the metropolis due to the replacement of buildings, the Cement and Asphalt Organization will absorb these levels more than they reflect the sun and has increased the temperature in urban areas. This application is considered as the creator of the thermal island for the metropolis.