Climatology
Ali Mohammad Khorshiddoust; Mustafa Tahani Yazdali; farahnaz khoramabadi; Aazam Samadi; Farideh Ansari Maleki; Mohammad Hossein Pourghorban
Abstract
Problems caused by climate change are one of the most important environmental crises and threats of human society, especially in urban environments. In the city of Tabriz and in recent years, due to the growth of the population, a lot of migration from other cities, traffic, the development of industries ...
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Problems caused by climate change are one of the most important environmental crises and threats of human society, especially in urban environments. In the city of Tabriz and in recent years, due to the growth of the population, a lot of migration from other cities, traffic, the development of industries and production centers have caused an increase in the production and distribution of pollutants. Based on this, in this research, attention has been paid to the evaluation of the quality of dust occurrence in the years 2019 and 2018. The concentration of dust particles in different areas of the studied places varies depending on the geographical location, topographical, climatic conditions and also their origin, both internal and external. Based on the results obtained from the analysis of laboratory results and field studies, in the Tabriz region and during the research period, the concentration of lead metal in dust is moderate for adults and severe for children, and the risk of mercury metal for both the elderly and children. It has been intense. The adverse effects of cadmium metal have been very severe in children and adults. On the other hand, the high air temperature in the city center and the formation of thermal islands in it causes local winds from the suburbs to the city center. With the transfer of pollution from the suburbs to the city center by these winds, the pollution situation in the city center also increases.
Climatology
Mehdi pourahmad; mostafa karampour; behroz nasiri
Abstract
The aim of this study was to reveal the relationship between land cover changes and changes in aerosol optical depth index in the Middle Zagros. In this regard, two categories of MODIS sensor remote sensing products were used. First, land cover changes in the study area were performed using MODIS sensor ...
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The aim of this study was to reveal the relationship between land cover changes and changes in aerosol optical depth index in the Middle Zagros. In this regard, two categories of MODIS sensor remote sensing products were used. First, land cover changes in the study area were performed using MODIS sensor land use classification derivative product. In the second part of the research, the trends of dust events were investigated based on the station data of the dust codes of 4 stations of Khorramabad, Shahrekord, Yasuj and Abadeh. In addition, the trend of Aerosol Optical Depth Index (AOD) was examined using MOD04-L2 Madis sensor product for the statistical period 2000 to 2020. The results showed that there were 6 layers of rangeland, forest, agricultural, urban, residential, barren and water areas in the Central Zagros, in which the forest floor has decreased by about 123 square kilometers per year. Rangeland cover, which is the main cover of the study area, has remained relatively stable, and agricultural land uses have increased significantly, from 7% in 2000 to 9.5% in 2020. Urban and residential lands had also increased. On the other hand, a review of the 21-year time series trend of the AOD index indicates an upward trend over the last 21 years. Among the land use classes, the two categories of pastures and forests, which in fact occupy more than 90% of the study area, have shown an inverse relationship with the AOD index. But the class of agricultural lands was directly related to the AOD index. Therefore, the decreasing trend of forest floor in the region has been significantly associated with the increasing trend of AOD in the region and on the other hand, the increasing trend of agricultural land has been associated with the increase of AOD in the region.
Climatology
Seyed Hossein Mirmousavi; Zahara Taran
Abstract
Introduction
Dust is one of the most common climatic phenomena in arid and semi-arid regions of the world The phenomenon of dust is a natural occurrence and occurs in areas with vast areas of arid and desert areas, Lack vegetation and other surface coatings. Due to its presence in the arid and semi-arid ...
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Introduction
Dust is one of the most common climatic phenomena in arid and semi-arid regions of the world The phenomenon of dust is a natural occurrence and occurs in areas with vast areas of arid and desert areas, Lack vegetation and other surface coatings. Due to its presence in the arid and semi-arid belt of the world, Iran is constantly exposed to local and synoptic dust and dust systems. In recent years, the phenomenon of dust in the Middle East has been increasing, Because it is one of the five regions of the world that has the highest dust production . Long periods of drought and inappropriate interventions in nature can increase the likelihood of this phenomenon.
In recent years, the trend of dust events in the west and south of Iran, especially in the spring and summer, has increased dramatically .This phenomenon is affected by certain atmospheric conditions and its distribution can affect the temperature, temperature, precipitation and atmospheric circulation conditions of the area during the months of the year.
Materials and methods
In this study, data of 56 years old (during 1961-2016) precipitation, temperature and dust on daily scale from 30 synoptic stations in the west and southwest of Iran were obtained from the country's meteorological organization. In line with this study, MATLAB, ArcGIS and SURFER softwares have been used. In order to analyze the information, recognition of fluctuations and the relationship between dust, temperature and precipitation have been used.
Results and discussion
Recognition of fluctuations and the relationship between dust, temperature and precipitation are investigated using regression, spectral analysis and Pearson correlation coefficient. Then it is represented by trend maps, cycles, and correlation tables. The results for the West and Southwest of Iran have been obtained and explained in detail.
Conclusion
The study of the spatial distribution of the trend shows that most of the stations studied in the dust and rainfall have an increasing trend and have been in a decreasing trend temperature. Spectral analysis of dust, dry days, and temperature showed that short-cycle cycles in addition to the most frequent distribution, showed a higher probability of occurrence than long-term periods. In most of the stations studied, the correlation of dust with temperature and dry days has a positive and direct, relationship with the rainfall has a negative and inverse relationship. The local mororan analysis for the spatial autocorrelation of dust with dry days in the western, northwest, northern and parts of the east of the study area has shown a high value cluster pattern (positive spatial autocorrelation). The spatial autocorrelation of dust with precipitation in the northeastern, eastern, and small parts of the southeast and west of the study area has a high cluster pattern (positive spatial autocorrelation). The spatial autocorrelation of dust with temperature in the eastern, western, and small parts of the south of the range has a high cluster pattern (positive spatial autocorrelation).
