Document Type : original Article
Abstract
Extended Abstract
Background and purpose
Earth's surface temperature is an important factor in global warming studies, and today it is the main challenge for many researchers worldwide. With remote sensing technology, it is possible to evaluate the temperature of the earth's surface and land use changes during different years with the help of satellite images, thermal infrared radiation, and physical models. In environmental studies, due to the location and location of the observations in the sample space, traditional statistics cannot be used due to the continuous structure of time and space. For this purpose, spatial statistics (spatial autocorrelation) is a suitable and new method for analyzing these data.
Materials and methods
In this research, satellite data related to Landsat 5 and 8 images for the years 1990 and 2020 were obtained from the American Geological Survey. After correcting the images, the land use maps of Jiroft city were prepared and using the combination of visible and infrared bands, land use maps were prepared. The transformation of different land use classes and their changes during these years were analyzed in IDRISI software. Also, 150 control points from Google Earth were exploited to evaluate the accuracy of classified maps. In order to obtain the temperature of the earth's surface, the thermal bands of the received Landsat images were used. In two steps, the spectral radiance was converted to the temperature of the black body, and the surface temperature of the earth's surface was calculated. Finally, to reveal the spatial pattern of local differences, the local Moran's spatial autocorrelation statistic has been exerted.
Findings and discussion
The results showed that from 1990 to 2020, part of barren and flood channel lands was converted into water areas, which increased with the dam's construction after 1990. The average temperature of the earth's surface increased by 11.1 degrees in 30 years, which can be seen in all uses. The reason for this increase can be seen as the increase in air temperature. Another reason for the increase in the temperature of the earth's surface is the increase in construction in the region. The classification of the earth's surface temperature classes showed that the very hot and warm classes in the southern parts increased in 2020, and the average (most change) and cold classes decreased. The local spatial correlation statistics analysis results showed that hot clusters are gradually concentrated in southern regions and cool clusters in northern and northeastern regions.
Conclusion
The findings of this research showed that despite the increase in agricultural and garden use and the decrease in barren areas, the earth's surface temperature would increase to a large extent in all uses. Although manufactured areas are also increasing, the main reason for the temperature of the earth's surface can be considered the increase in air temperature and climate change.
Main Subjects
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