Showing 22 results for Remote Sensing
Dr Vahid Safarian,
Volume 12, Issue 3 (12-2025)
Abstract
Objective: This study aims to analyze greenhouse gas variations across Iran and to identify the gases that exert the greatest influence on their overall dynamics. The findings enhance understanding of atmospheric pollution patterns and support the development of effective mitigation strategies. These results provide a scientific basis for climate-change mitigation planning in Iran. The study relies on satellite-based remote sensing datasets.
Methods: This study analyzes the temporal and spatial variations of major greenhouse gases including carbon monoxide, nitrogen dioxide, ozone, water vapor, and methane across Iran from 2019 to 2024. Sentinel-5P satellite data were extracted via the Google Earth Engine platform, and after filtering and removing low-quality observations, the data were standardized using the Z-Score method to enhance comparability and correlation analysis. Principal Component Analysis (PCA) was applied to reduce data dimensionality and identify dominant variation patterns. Temporal and spatial trends were then quantified using complementary statistical techniques.
Results:
Methane exhibited a consistent increasing trend from late 2021 through 2024 and accounted for the largest share of total variance (R² = 0.87), likely reflecting intensified anthropogenic activities and regional climatic shifts. CO, NO₂, and O₃ were mainly affected by seasonal fluctuations and nonlinear factors, and no clear long-term increasing or decreasing trends were observed. Water vapor showed a direct relationship with temperature variations, water sources, and atmospheric patterns, with its lowest concentrations recorded during the cold months and increases observed in the warm months. PCA analysis indicated that the first two principal components explained more than 70% of the total data variance, with CH₄, O₃, and NO₂ contributing the most to the overall variations.
Conclusions: The study results indicated that greenhouse gas variations in Iran are simultaneously influenced by natural factors and human activities. The combination of satellite data, statistical analysis, and PCA enabled a precise assessment of the temporal and spatial trends of greenhouse gases, providing valuable information for planning pollutant reduction and developing strategies to combat climate change.
Mahmoud Hooshyar,
Volume 12, Issue 4 (12-2025)
Abstract
Land use is one of the most important aspects of studying natural resources management and reviewing environmental changes, and studying it is also very important in understanding the microclimate of urban areas. Therefore, according to the importance of the topic in this research, the spatial pattern of land use changes and surface temperature in Bukan city in the statistical period of 1990-2020 using Landsat satellite images and sensors (OLI-TIRS, ETM+, TM) and the separate window algorithm. was evaluated. The results showed that the land use of the area has changed a lot during the period under review, so that the residential use has increased and the agricultural use has decreased. The results of the survey of the earth's surface temperature also showed that in 1990, the highest temperature was related to pasture areas and barren lands with a temperature between 32 and 40 degrees Celsius and the lowest temperature was related to areas with dense vegetation with a temperature between 15 and 20 degrees. It is Celsius. The temperature in residential and urban areas varies between 28 and 31 degrees Celsius. In 2020, the average temperature of pasture use was 35 degrees Celsius, residential use was 30 degrees Celsius, and garden and agricultural land was 14 and 24 degrees Celsius, which, apart from pasture use, which did not change significantly, other studied uses increased. They show a temperature of 2 to 4 degrees Celsius compared to 1990. The examination of the temperature in relation to the land use changes showed that there is a high correlation between the land cover and the surface temperature of the land, so that in some of the sampled places, it showed that the change in the use of gardens Residential use or pasture has caused an increase of 15 to 20 degrees Celsius in the temperature of the earth's surface in these areas. Based on the results of land use and overall vegetation, it has an indirect and strong relationship with the surface temperature of the earth, and with the increase in the area of residential and barren lands and the decrease of vegetation and agricultural lands, the surface temperature of the earth will increase.
