جستجوی مقالات مرتبط با کلیدواژه « dust » در نشریات گروه « جغرافیا »

Dust is a significant global challenge. This study aimed to monitor the temporal and spatial changes of suspended atmospheric dust in the western half of Iran, specifically in the provinces of Ilam, Khuzestan, Kermanshah, Kurdistan, and Lorestan. We utilized MODIS sensor products from 2012 to 2021 and Sentinel-5 imagery from 2018 to 2021 within the Google Earth Engine framework. These sensor products are invaluable for managing and addressing dust-related issues. Using Aerosol Optical Depth (AOD) and Absorbing Aerosol Index (AAI) data, we tracked the trends in aerosol concentration over time and across the selected regions. Additionally, we calculated the Enhanced Vegetation Index (EVI) and Bare Soil Index (BSI) from MOD13Q1 images for the same period to assess their average changes. The analysis revealed a downward trend in AOD during January and an upward trend in July. The AAI indicated that January 2021 recorded the lowest aerosol levels, while July and September 2021 experienced the highest concentrations. Classifying aerosol concentrations into three categories highlighted that regions with high aerosol levels, as indicated by MODIS data, were consistently found in Khuzestan and Ilam provinces, while Sentinel data showed sporadic occurrences. Furthermore, the correlation between dust concentration from MODIS imagery and EVI and BSI indices revealed that the highest aerosol concentrations were located in areas with little vegetation and bare soils.

In order to monitor dust storms in Khuzestan province, statistical data were first obtained from the General Meteorological Department, and the days with dust reports with minimum horizontal visibility of less than 10 km were selected as free days. The results of zoning and the average dust concentration map by calling MODIS satellite data in Google Earth Engine revealed that the density of this phenomenon was in the western, southwestern and central regions of the province. For the synoptic investigation of this phenomenon, the most intense dust storms were selected for 9 synoptic stations and these days were analyzed by drawing synoptic maps; And the movement path and origin of this phenomenon and its density were displayed through the HYSPLIT model. The results indicated that in the majority of dust storms in the south of Iran, thermal low-pressure systems were active, and in Europe, high-pressure systems prevailed, and the slope of the pressure gradient between these two systems led to the direction of westerly currents with high wind speed at high altitudes towards the study area. And the prevailing rotating situation in the region has added to the instability of the air. The western winds have also passed through the deserts of North Africa, the north of the Arabian Peninsula, Iraq and Syria, parallel to the Nave canal in the west of Iran, and have led the hot and dry air of these regions to the atmosphere of the region.

In addition to natural disasters such as floods, which cause great damage to the environment and human societies, the phenomenon of dust also causes irreparable damage to urban environments, transportation systems, respiratory systems, etc. Identifying Potential Dust Source Areas is considered the first step to control and prevent this phenomenon. Various researches have been conducted to identify dust sources, but most studies have relied on small-scale images. This research aims to use medium-scale satellite images to identify local areas prone to dust production. Google Earth Engine was used to analyze factors influencing dust generation, including slope, Digital Elevation Model (DEM), land use, soil salinity, Normalized Difference Vegetation Index (NDVI), soil moisture, wind speed, precipitation, and Land Surface Temperature (LST). Analytical Hierarchy Process (AHP) was used to assign weights to these elements. The resulting weights were: soil moisture (0.264), NDVI (0.208), wind speed (0.153), precipitation (0.107), land use/soil salinity (0.081), LST (0.064), DEM (0.024), and slope (0.020). The inconsistency index (0.015) indicated a high degree of consistency between the assigned weights, which is below the acceptable threshold (1). Due to the lack of ground-based air quality measurements, the Aerosol Optical Depth product (a satellite-derived measurement of airborne particles) was used to validate the resulting dust source maps. The final map showed that the potential for dust generation decreased closer to the heights of Sahand and increased closer to the lake.

During the recent years, the dust phenomenon has grown significantly around the world following the occurrence of dry periods and the average increase in global temperature. Therefore, the regions located in the dry belt of the world have been more affected by this extreme phenomenon than other regions.The main goal of this research is to investigate the synoptic patterns and the role of regional circulation of the atmosphere in the production of local and regional dust in Qazvin province. It is internal and external, and in this research, it has been tried to investigate and analyze the different dimensions of regional and extra-regional dusts using methods and data with high resolution.In order to analyze dusty days in Qazvin province, two environmental and circulation databases were used. In this way, first, according to the meteorological data recorded in the ground level stations, the number of dust days was determined and then the circulation patterns that generated them were identified. The formation of environmental databases was done in such a way that the number of dusty days in the province in a 20-year period (2002 to 2021) for 5 Hamdid stations using the code of current weather phenomena (WW) of the country's meteorological organization (codes 6 and 30 to 35, which are related to dusty days) ) was determined in MATLAB software.In order to analyze synoptic patterns and the role of regional atmospheric circulation in local and regional dust production over Qazvin province in a 20-year period, the following results were obtained.- Station surveys during the statistical period showed that the majority of local and regional dust occurrences in the province are related to the hot period of the year and especially the summer season, which accounts for the largest amount of dust transmission in the region. On the other hand, the cold period of the year, especially winter, has the lowest percentage of dusty days in the province.- The results of the investigation of atmospheric circulation in the region for periods of intense and pervasive dust showed that 4 circulation patterns are the main cause of this phenomenon in Qazvin province. The mentioned patterns have a regional and extra-regional nature, and in this category, we can mention the high-altitude formation of a tropical front with a strong descent of air and an increase in negative relative humidity as a regional factor. Among the extra-regional factors, we can mention the downward expansion of the polar ice cap and the formation of deep troughs on the main sources of dust in the Middle East, which have created periods of intense and pervasive dust in the region.- The circulation of the lower level also showed that for the formation of dust in the region, southern currents were the main ones, although in some patterns, northern currents also carried dust particles. The increase in wind speed over the main sources of dust and on the other hand the increase in wind speed over Qazvin province also showed the interaction of sub-level pseudo-jets in the formation and transfer of dust particles.- The results of tracking dust particles indicated that the main source of dust in the region is Iraq and other dust producing sources in the region have a reinforcing effect. In such a way that the transport of particles with the monitoring of more than 48 hours in the region showed the existence of local currents which were at the heart of the circulation of the regional scale and caused the rise of dust from the country of Iraq. It is necessary to explain that sources such as the country of Turkmenistan have also played a role in the occurrence of intense and pervasive dust periods in the region, which aggravate the conditions during the combined process with the flow to the region. Among other sources of dust, we can mention the border areas of southwestern Iran, where the process of desertification in this area has caused it to become a focus for dust in the neighboring areas.- The results of the dust transfer volume showed that the highest AOD value is observed in the third pattern, during which in the range of the regional circulation of the atmosphere, the high-tropospheric system prevails and the interaction between the trajectories and the intensity Relative humidity can be an efficient tool in predicting very intense dust storms in the region. The atmospheric system that has the lowest concentration of particles in dust periods is the southward expansion of the polar ice cap and the formation of deep troughs over the dust centers of the Middle East, which was less intense than other atmospheric patterns.Based on the obtained results, it was observed that the internal foci also play an important role in the formation of dust periods, as mentioned by (Namdari et al., 2019). (Latfi Nasab et al., 1400) also showed that the formation of low-level jets played an important role in the transfer of dust in the region, and in this research it was also observed that the presence of strong low-level wind currents is one of the important factors in the formation of periods There is dust in the area.The circulation database includes geopotential height data of 500 hectopascal level, orbital and meridional wind components, which were used to determine the circulation pattern of dusty days. The statistical period of the circulation database is in accordance with the environmental database and data extraction was done through programming in the software environment (GrADS). The geographical area of circulation data is 0 to 60 degrees of latitude and 10 to 90 degrees of longitude. The upper atmosphere data were obtained from the European Medium-Term Weather Forecast Database (ECMWF) from the ERA5 data series with a resolution of 0.125 degrees.In order to extract dust generation patterns, factor analysis and cluster analysis were used to identify factors and categorize atmospheric patterns on geopotential height data of 500 hectopascals.

Dust events are one of the most important and challenging environmental and climatic hazards of the whole country and especially of Khuzestan province. The main goal of this research is to reveal the role of changes in vegetation cover and soil moisture in the annual distribution of dust events in Khuzestan province. In this regard, 3 categories of data were used. The data related to station dust codes obtained during the statistical period of 2010-2020 for the synoptic stations of Khuzestan province on an hourly scale. The second set of monthly vegetation data was obtained from the NDVI product (MOD13C3) of the MODIS sensor, and finally, the moisture data of the upper 5 cm layer of the soil was provided from the SMAP sensor on a monthly basis. By analyzing the frequency of dust codes, the monthly frequency of dust events, the concentration and persistence of dust were investigated. By obtaining the spatial average values of the two moisture indices of the upper 5 cm soil layer and the monthly NDVI index, the correlation and relationship between the dust indices and these indices was analyzed. The results showed that based on the average period of 2010-2020, the period of 4 months from May to August is the dust peak period in the province. There are at least 11 days of dust in every month, and the concentration of dust is more than 2800 micrograms per cubic meter in the air, and the duration of the dust event in the province is at least 40 hours. The investigation of the moisture indicators of the upper layer of the soil and vegetation showed that, exactly in the province during the same dust peak period, the soil moisture of the upper layer of the soil reached less than 10% in a large part of the central and southern regions of the province, and at the same time, the vegetation index also In these sectors, it has reached less than 0.18. In addition, in this research, it was observed that the monthly changes in the moisture content of the upper 5 cm layer of the soil with a correlation coefficient of -0.88 have the greatest effect on controlling the dust concentration in Khuzestan province.

  As one of the most essential needs of living beings, clean air quality has been threatened by natural and human activities. In recent years, dust storms have been increasing spatially and temporally, causing numerous damages to social, economic, and environmental health for the residents of the southern and southwestern regions of Iran. In the present study, MODIS sensor data were used to investigate dust storms and detect horizontal optical depth.

The  advantages of MODIS sensor data include high spectral and temporal resolution. Additionally, meteorological station data were collected based on the study period. After preprocessing the data and preparing field observations, the necessary features for modeling were extracted using the differential method between selected bands of each MODIS sensor image, along with features extracted from ground-based meteorological station sensors. After further investigations and evaluations and using the viewpoints of meteorological experts, 36 differential features from various MODIS image bands and six features from ground-based meteorological station data, totaling 42 features, were extracted. Subsequently, using feature selection techniques, the best features were identified. A novel method named ML-Based GMDH, which improves the GMDH neural network by altering partial functions with machine learning models, was employed to detect dust concentration and horizontal optical depth. To achieve optimal accuracy, the hyper-parameters of this model were heuristically tuned using the TLBO optimization algorithm. Additionally, machine learning methods such as Basic GMDH, SVM, MLP, MLR, RF, and their ensemble models were implemented to compare with the main approach. According to the results, the TLBO-tuned ML-Based GMDH method provided superior accuracy in detecting dust concentration compared to the aforementioned machine-learning methods.

The SVM-PSO method was selected as the best method in the feature selection phase, the RF method was chosen as the best method among basic classification methods, and the Ensemble SVM and Ensemble RF methods were selected as the best methods in the ensemble and classification phase. It was also observed that using the ensemble approach led to a desirable improvement in horizontal optical depth classification. In the second approach, a method titled ML-Based GMDH, which improves the GMDH neural network by altering partial functions with machine learning algorithms, was used for estimating dust concentration. Additionally, to achieve suitable accuracy, the hyper-parameters of this model were finely tuned using the TLBO optimization algorithm. The results showed that this method provided appropriate accuracy in estimating dust concentration and horizontal optical depth, out performing the best-selected methods from the first approach

The aim of this study was to identify the epicenter and co-occurrence factors of dust storm wave from 1 to 3 November 2017 in Kermanshah. To investigate the synoptic conditions of the causes of this phenomenon, from the European Central Center (ESMWF) mid-term weather forecast data set with a resolution of 0.125 degrees of arc including, geopotential height, omega, sea level pressure, orbital and meridional components, humidity. The Lagrangian method of HYSPLIT model was used to orient the source of dust particles. in this study, dust storm WRF-chem was simulated using a paired numerical weather forecasting model. Finally, through the processing of MODIS satellite images, its scope was determined. Examination of HYSPLIT tracking maps shows that two general paths for dust transfer to the area can be identified. 1- The northwest-southeast route, which passes through dust cores formed in the deserts of Iraq and Syria, transports dust to the western half of Iran. 2- Southwest to west of Iran and Kermanshah, which is the main source of dust on November 2 and 3, The source of the particles is Kuwait, northern Saudi Arabia and part of Iraq. The spatial distribution of the dust interpreted by the MODIS sensor images is consistent with the spatial distribution of the dust concentration simulated by the WRF-chem model.

Extensive and massive agriculture, along with other agricultural activities such as animal husbandry, industrial activities in the southern half of the province, has created and intensified extensive changes in the environmental resources and natural structure of the province. This extensive change can show its effects and consequences in the destruction of forest lands, the transformation of rich pastures into poor pastures and barren lands, severe soil erosion, and finally the creation and development of internal centers of dust. and intensify the severity of dust incidents in the province. Dust events have profound and significant effects on agriculture and soil fertility, health and hygiene, disruption and destruction of industries and power plants, and negative effects on the environment, including the deterioration of forests. Airborne particles, which are mainly driven to the region by dust storms, are one of the important components of the atmospheric system. They can not only change the albedo of the energy balance by acting as cloud particle nuclei, or ice nuclei.

The study location of this research is Khuzestan province, which is one of the most challenging provinces in the country in terms of environmental hazards. This province, with an area of about 6.5 million hectares, occupies about 4% of the country's area. Dust is one of the major and most important challenges of this province. Its destructive effects can be traced in various dimensions, such as the quality of water resources, the quality and performance of agricultural products, industries and energy transmission networks, and the air quality of cities. Three categories of data have been used in this research. The data of the first category is related to the data of widespread dust days in Khuzestan province. These data were obtained from the dust codes of the current air condition (ww parameter of synoptic stations of the province) during the statistical period of 2000, 2020. The second category of data was actually the remote sensing data of MODIS sensor, which included the Aerosol Optical Depth (AOD) product of MODIS sensor (MOD04 product) and Aerosol Exponential Index (AEA). These two indicators are dimensionless but with different directions. In the AOD index, higher numbers represent more aerosols in the atmosphere and in the AEA index, in addition to the presence of dust in the place, it also provides the size of the aerosol particles. Finally, the third category of data is the reanalysis data related to incoming net shortwave radiation (SNSR), which was taken from the reanalysis data of the European ECMWF database version ERA5 with a spatial resolution of 0.5 arc degrees. 

In this research, it was tried to investigate the influence of the dust event in the context of fluctuations and daily changes in the amount of net shortwave radiation received on the earth's surface. The results of the investigation of three cases of widespread dust in the province showed that in these three cases of widespread dust, aerosol particles are generally in the central, southern and western parts of the province (plain and lowland areas of the province) from the type of medium to large particles (index angstrom between 0.5 and 1) and in the eastern and northeastern parts, it was of the type of coarse particles (angstrom index less than 0.5). In the context of the impact of dust events on the amount of shortwave radiation received by the earth's surface, it was seen that in the dust event of July 22, 2010, the Angstrom exponential index indicates the presence of coarse particles in the atmosphere near the earth's surface and the AOD index also indicates the presence of dense dust in the entire area of the province. The received net shortwave radiation (at 12 noon or 09 UTC) was about 194 watts per square meter (about 28 percent) lower than the average for the same month. This drop rate was less in the other two dust waves, whose AOD and Angstrom index values indicated finer and less concentrated dust. In the dust wave of June 19, 2012, the amount of net shortwave radiation received was only 5% (25 W/m2 at 12 noon or 09 UTC) less than the long-term average, and this drop in the dust event of May 12, 2018 was equal to 28 W/m square (about 4% drop compared to the average of the same month).

The aim of the present study is to dynamically model the spatial-temporal characteristics of dust in the south and southeast of Iran with REG-CM4 model using monthly dust data and RegCM4 data. For this purpose, the dust distribution of the IDW method along with the dust diagrams were plotted. The RegCM4 model was implemented with the paired Lambert image imaging system for 40 km horizontal separation with the paired chemistry model. The location of monthly and annual dust distribution shows the highest amounts of dust for the cities of Zabol, Bandar Abbas, Zahedan and Jask compared to Sirjan, Kahnooj and Lar stations. The highest frequency of dust in Sistan and Baluchestan (48%), Hormozgan (27%) and Fars provinces with 16% and the lowest frequency for Kerman province (9%). In general, the summer seasons (at Sistan station) and the winter (Kerman station) have the highest and minimum dust events, respectively. The time survey also has the highest amount of dust for the warm months of the year and the lowest for the cold months of the year. July at Zabol station and November and December at Sirjan station have the highest and lowest dust levels, respectively. The RegCM4 climate model also shows maximum dust on the southeast, south and south coasts for different variables.

Climatic factors and elements play a role in hydropower and soil type and are very effective in the creation and development of dust. The data of 13 stations (climatology, rain gauge, and synoptic) were used in a 33-year period from 1368 to 1400, and the water balance of the province was estimated using the Thornth-White method. Two stations, Manjil and Rudkhan Castle, were chosen as models for dust production. The area of Gilan province is 13,790.5 square kilometers and the geographical location of Rudkhan Castle is 37°06'N 49°16'E and the height above sea level is 1677m, its area is 1052/28 km and Manjil is 36°46'N 49°30'E, the height from the sea is 263 and the area is 29/1072 km2. Gilan province is in the north of Iran with a geographical length of 35/50 to 32/48 and a width of 27/38 to 33/36 in the north with the Caspian Sea, in the east with Mazandaran province, in the south with Qazvin province, and in the west with Azerbaijan and Ardabil. Soil moisture consumption in GIS environment was interpolated and mapped by kerjing method throughout Gilan, and two desired points (Manjil, Rudkhan Castle) with maximum and minimum consumption were determined on the map. Changes in soil moisture consumption are the most important icons influencing dust production. In drier climatic regions - Manjil - the consumption of soil moisture increases and the conditions for the separation of soil particles are provided. Despite the fact that the wind blows in Manjil most of the year, it causes the production of dust and it gets worse in the hot season.

This research investigated the specific patterns of dust influx into the metropolis of Tehran from 2005 to 2017. The study utilized the data on dust occurrence days and synoptic station data in Tehran. The research methodology involved employing the HYSPLIT trajectory model, as well as dust detection indices, and determining the chemical properties of dust, including main and rare elements, by using the X-Ray Fluorescence (XRF) method. The findings indicated that the primary source of dust entering Tehran originated from desert regions and vast, arid areas outside the country. External sources of dust, such as the North Arabian Sahara and the East African Sahara, have been active since ancient times and are not solely related to modern dust occurrences. The cause of their impact on Tehran could be attributed to the desiccation of internal lagoons and lakes. The changes in the frequency of fine-dust trajectories could not be solely explained by their connection with external sources. Instead, it appeared that the micro-particle movement system was striving to establish a deeper order, which was not solely influenced by changes in the origin and destination of the particles. Rather, the entry of fine particles into this movement system had undergone changes during their movement within the system.

Urban dust is one of the indicators of heavy metal pollution in the living environment. Heavy metals in contaminated soils are considered a challenge to the environment and cause irreparable effects on the bodies of living organisms. Therefore, it is very important to know the pollutants and how they are transported, their performance, and accessibility. Because their effects on the health of humans and other living beings are significant. Therefore, the present study was conducted to investigate the effect of heavy metals (including Pb, Zn, Cr, and As) in the dust of Birjand City on human health. For this purpose, 50 dust samples were collected from Birjand city and analyzed using inductively coupled plasma spectroscopy (ICP-OES). According to the research results, the average concentration of studied metals was estimated as Pb (16.93), Zn (5.55), Cr (1.04), and As (6.11) µg/m³. Average RI values, Cr and Zn metals have a low ecological risk potential, lead has a medium risk, and As has a high ecological risk potential. The non-carcinogenic risk of heavy metals in Birjand city is without risk. However, the non-carcinogenic risk for two elements, Cr and As, is greater for children than for adults. CR values are higher in children than in adults. This amount is in children for Cr (5.58*10-4), As (5.98 * 10-5), and lead (9.09*10-6) and in adults for Cr (1.18*10-4). and As (1.27*10-5), which is more than 1*10-6. There is a risk of cancer in children under controlled conditions. However, the cancer risk caused by this metal in dust for adults can be ignored.

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.

In recent years, South-east and east of Iran has become one of the most important hotspots of dust events due to numerous droughts, upstream dams and severe land use changes. In order to evaluate the seasonal variations of dust, 15 synoptic stations were selected during 1980–2015 and then extracted from the present weather codes. Additionally, the AOD index of the Terra MODIS satellite sensor and the Aura Satellite Aerial Index of Absorption (AAI) were used during the period 2015–2005. Mann-Kendall nonparametric test was used to investigate the trend of dust days and Spearman correlation method was used for correlation of dust days. The average days of dust in this region are 9 days and maximum days of dusty days are 45 days that occur in Zabol station at summer. Intra-seasonal variations of dust over east and southwestern of Iran have two maximum phases at spring and summer. Dust also has an inverse relationship with altitude and latitude. Climate parameters, drying up of rivers and lakes, and land use changes are three major factors in dust production in eastern and southeastern Iran. Main sources of dust production and emission over the region are (1) Makran coast; (2) Hamoun and Jazmourian dried bed (3) Lut Plain and (4) Border region of Iran, Afghanistan and Pakistan. At most stations except Zabul, Bam and Kerman have an increasing trend of dust events.

One of the factors influencing the changes in the morphology of desert areas is the frequency of wind blowing due to the relative poverty of wind blowing and the surface and covering cover in these areas. Wind transport of sand is a complex process that depends on factors such as wind speed, amount of bare soil, dry air conditions, soil grain size, vegetation, local and external air system, short-term discharge, extent of deforestation, in an area. Based on this, the activity of winds in carrying out erosion is significantly related to the climatic conditions of each region. Wind erosion in desert areas is seen in the form of sand dunes.The importance of sand dunes studies is due to their impacts on water and soil resources, flora and fauna, human infrastructure, and roads. Therefore, for the purpose of basic planning, monitoring the speed and direction of movement or the expansion of sand dunes, due to the damages caused by it and especially the preservation of natural resources and human projects and facilities, is of special importance in the management of desert areas.

In this research, wind characteristics, dust characteristics, soil moisture and its effects on Zabol region are investigated. To check wind speed and direction, the data of Zabol anemometer station were evaluated in Wrplot software. Then, the sand graph was drawn in SandRose-Graph software in order to check the indicators of sand movement. The changes of dust and AOD index of the region were extracted in the Erthengine system and MODIS satellite images in the period from 2012 to 2023. Changes in soil moisture index in the region were also monitored using SMAP satellite images in Arth Engin.

In this research, the predominant wind direction of the region was determined as northwest-southeast by examining the wind direction of Zabol station. On the other hand, examining the trend of wind speed changes at Zabol station shows that the average wind speed at Zabol station has been increasing over the past 56 years; So that the average wind speed has reached from 2.5 m/s per month in 1962 to about 4.8 m/s per month in 2018, which shows an increase of 2.3 m/s during this period. The amount of sand carrying potential (DPt) at this station is 2079/8, which is estimated to be high based on Freiburger's and Dean's classification of wind energy at this station. The variability index (UDI) of wind directions for Zabol station is in the low variability group with the classification of unidirectional and channelized winds, which greatly increases the intensity of erosion and dust production. The highest amount of displaced sand (DSF) in Zabol station indicates the amount of sand particles transported in the region.
In addition to examining the characteristics of the wind in the region, the changes in the dust index (AOD) and aerosol were also carried out using MODIS sensor images in the environment of Erth Engin from 2012 to 2023, and the results showed that the highest percentage of dust with a size greater than 55 microns and less than 47 microns in the summer of every year and with the decrease in surface humidity and the increase in temperature and the occurrence of 120-day winds in Sistan, also the examination of the percentage of dust changes in the air in the 5-year period from 2018 to 2023 showed a significant increase. which indicates an increase in the percentage of airborne particles due to the expansion of wind erosion in the region.
Next, the soil moisture of the region was monitored using the Smap satellite image series, including changes in the percentage of surface and subsurface soil moisture in the Zabol region in the Google Earth Engine environment and the time period from 2015 to 2023, and the results showed that the highest percentage of soil moisture is from February to April. And the lowest percentage of soil moisture is from July to September, which corresponds to the occurrence of 120-day winds in Zabol region.

The results obtained from this research show that the main cause of dust occurrence in Zabol region is the increase in the wind speed in the region in the long term and the increase in dust supply centers around the region, which, along with climate change and the decrease in rainfall and the occurrence of drought, in the scale Locally, the drying up of Lake Hamon as a result of the Afghan government's non-compliance with the 1351 Kabul agreement regarding the introduction of 850 million cubic meters of water per year into Lake Hamon has had a significant impact on this issue. Considering the location of the dried Hamon lake in the northwest and west of Zabol city, and the direction of the prevailing wind, it can be said that most of the dust particles transported to Zabol originate from this area. Therefore, the only solution to the current situation of Zabol can be the restoration of Lake Hamon and stabilization of the sediments on the bottom of Lake Hamon. On the other hand, the presence of channelized and dominant northwest-southeast in the region has provided the conditions for the construction of wind power plants in this region, considering the criticality of the country's energy, which is used with proper planning and investment for this issue.

Urmia Lake is one of the largest saltwater lakes in the world, which unfortunately is drying up and has caused many dangers and concerns, especially in relation to salt dust in its dried areas. Therefore, in this research, we tried to investigate the relationship between vegetation and dust in the cities around Lake Urmia. Salinity in plants causes physiological disorders, salt stress causes growth, photosynthesis, protein, respiration, energy production, premature senescence, water reduction in plants. Considering these effects, it was tried to evaluate the overall health of plants by using related indicators including NDVI, CIre, GCI, CRI2, NDWI, NDII, MSI, PSRI. These indicators evaluate the amount of plant water, plant water stress, photosynthesis capacity, plant growth and water deficit, the amount of chlorophyll, nitrogen and pigments, which are related to plant energy and health. According to these indicators, the health of plants is generally in a favorable condition, and mostly the highest numerical values of the indicators were assigned to gardens. Using Landsat and Sentinel 2 images and the NDVI index, the vegetation changes of the region were determined in the period from 2010 to 2020, and then using the MERRA-2 database, the amount of dust concentration was also extracted for the mentioned years. The results showed that the average NDVI in the studied area follows a constant trend with an overall average of 0.2957 and sometimes it increases or decreases due to the influence of external factors such as dust. Based on this, the highest (0.3495) average NDVI is related to 2018 and the lowest (0.2579) is related to 2013. Also, two methods of linear and logarithmic regression were used to investigate the relationship between vegetation cover and dust, and the results showed that based on the linear (0.7703) and logarithmic (0.7915) regression, the highest coefficient of explanation between the two mentioned indicators was in May. have been.

Soil and air are two essential elements in the life of creatures on the earth. Their interaction in certain conditions can cause many risks; among these dangers, dust storms can be mentioned. Under the conditions of dust storms, a large amount of dust is emitted in the air and the horizontal visibility is reduced to less than 1000 meters. Therefore, due to the important role of the dust phenomenon, it is highly necessary to understand the spatial-temporal changes and to analyze their long-term variations. Jazmurian region, located in the southeast of Iran, between the two provinces of Kerman and Sistan and Baluchistan, has become completely dry and turned into a desert due to drought and construction of numerous dams, and has turned this region into one of the key areas of dust production in the country. Therefore, the purpose of this study is to investigate the temporal-spatial changes of dust storms in relation to climatic parameters in Jazmurian wetland, which is of particular importance in order to properly manage this area to face the problems caused by dust storms.

In order to carry out the present research, the meteorological data related to the synoptic stations located in the Jazmurian wetland area for a period of 20 years (2000-2020) were received from the Iranian Meteorological Organization. Climatic data used in this research include temperature, precipitation, relative humidity, wind speed and direction, horizontal visibility, and remote sensing data including Aerosol Optical Depth (AOD) and Normalized Difference Vegetation Index (NDVI). The research method uses a combination of statistical analysis, observation and remote sensing. In order to check the AOD and NDVI, the monthly data of MODIS sensor was used. In this study, 12 synoptic stations that had the longest and most complete statistical periods were used in order to identify the temporal-spatial changes of dust occurrence in Jazmurian wetlat. The Mann-Kendall test was used to examine the trend of time changes. The slope of the Sen estimator was used to check and confirm the accuracy of the trend changes. In order to better understand the spatial distribution pattern of dust events in the Jazmurian wetland basin, the inverse distance interpolation method (IDW) was used. Also, Pearson's spatial correlation analysis was used to investigate the mutual effects between the indicators.

The 20-year average review of the indicators showed that the maximum value of aerosol optical depth in the studied area was 0.3, which is seen in the central part of the wetland. The vegetation index also showed that the maximum value of this index was 0.2, which covers most of the northern, northwestern and western parts. Examining the average rainfall trend showed that the maximum and minimum rainfall in this period are about 219 and 85 mm, respectively. Meanwhile, the 20-year average temperature survey showed that the maximum and minimum temperatures were 28.7 and 17.2 degrees Celsius, respectively. The fact that the maximum rainfall is in the northern and western part is in harmony with the minimum temperatures in these areas. The examination of the average wind speed showed that the maximum speed was 3.6 m/s, which was mostly in the central, west and northwest, south and southwest parts. The results of the wind direction index showed that the lowest wind direction is in the northern parts of the region and the highest wind direction is in other parts of the Jazmurian wetland basin. The maximum humidity in the studied area is 43.73%, which is mostly seen in the north, northwest, west, south, and southwest parts.  Examination of the horizontal visibility index showed that the maximum amount of horizontal visibility was in the northeastern and northwestern parts of the region. Also, the process of changes in the Mann-Kendall test showed that the annual averages of the indicators of wind direction, wind speed and horizontal visibility have been increasing with a positive slope, and the trend of changes in the relative humidity index has a negative slope and indicates a decrease in the period of 20 years. The results of the correlation analysis (at a significance level of 5%) showed that the highest correlation of the optical depth index was with the wind direction parameter and the lowest correlation was with the relative humidity index.

The growing trend of the emission of dust particles caused by the phenomenon of wind erosion in recent decades has caused major concerns at different regional, national and global levels. Therefore, it is necessary to understand the temporal-spatial changes of the dust caused by these events in order to reduce their adverse consequences in different regions. Accordingly, in this research, with the help of this knowledge, information related to the optical depth of particles in the air (AOD) and the vegetation cover index (NDVI) were investigated using the MODIS sensor satellite data. Using the meteorological data received from the website of the National Meteorological Organization, the climatic data of rainfall, temperature, relative humidity, horizontal visibility, wind direction and wind speed were evaluated in the period of 2000-2020 and finally the correlation between the AOD index and other climate parameters was evaluated. The results of the optical depth investigation showed that the maximum optical depth is located in the central parts of Jazmurian wetland. The trend of changes in rainfall and temperature indicators also showed that the trend of these two parameters was increasing; this increase in temperature is more noticeable. Correlation investigation between optical depth and other parameters showed that the highest correlation of optical depth index was with the wind direction parameter and the lowest correlation was with the relative humidity index. In general, we can conclude that the optical depth of airborne particles is highly dependent on environmental factors, which is more evident in arid and semi-arid areas, especially in Iran and the Jazmurian wetland area. In recent years, the area of the wetland has acted as a source of dust. Therefore, by using the remote sensing data obtained from the MODIS sensor and the climate data, it is possible to examine and analyze the trend of dust changes in the units of time and space.

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.

The aim of this study was to analyze the temporal and spatial nature of dust storms during the period 2016 to 2018 in Kermanshah Using the HYSPLIT routing model and the MCD19A2 product, the Modis sensor was performed in the Google Earth web engine.In order to route the origin of dust particles, the Lagrangian method of HYSPLIT model was used in 48 hours before the occurrence of dust phenomenon in Kermanshah at three altitude levels of 200, 1000 and 1500 meters.Findings from HYSPLIT model tracking maps indicate that the general route for dust transfer to the study area is the north-west-southeast route with the origin of the deserts of Iraq and Syria at three altitudes of 200, 1000 and 1500 meters. On June 17, 2016 and October 27, 2018, as well as the southwest-west route originating in Kuwait, Northern Saudi Arabia and part of Iraq on November 2, 2017.The results of the maps obtained from the MCD19A2 product of the Modis sensor, especially the maps of periodicity, cumulative concentration, spatial variation and the highest AOD map, show a high correlation with the routed maps extracted from the HYSPLIT model. In general, based on the findings of the maps extracted from the product MCD19A2, Modis sensor during the period 2016 to 2018 in Kermanshah, the central and eastern regions have always been more affected by dust storms than in other parts of the city. On average, they were more exposed to dust pollution than other parts of the city. In this regard, the final results show a high correlation between the actual PM10 data and the AOD values derived from the MODIS sensor.

Desert dust is formed under the influence of the special weather and environmental conditions of desert areas, enter the atmosphere. Localized hurricanes caused by ground air instability and sweeping dry deserts clear silt and sand particles enter the atmosphere from the surface. Ecologically as well as physically desert dust Effects such as pulmonary heart disease, disruption of plant physiological circulation, and erosion of growing structures include heavy metals deposited on soil surfaces, water surfaces, and canopies Plant surfaces that cause chemical changes and physiological damage to environmental ecosystems. Difficult Metal generally refers to a group of metal elements with a specific gravity of 6g/cm3 or more. Atomic weight greater than 50 g. Heavy metals important from an environmental point of view Cadmium, arsenic, cobalt, vanadium, zinc, mercury, iron, manganese, nickel, lead, chromium, copper, that do not decompose naturally. In addition, the long life of heavy metals is also considered. In the studies that have investigated the effect of dust on citrus fruits, it has been very few and even garden plants have been done on a case-by-case and limited basis. Citrus and especially oranges are one of the important and economic garden products in Iran, which are cultivated in tropical areas with mild and cold winters. Khuzestan plain, especially Dezful, is one of the poles of citrus and orange cultivation. But in Khuzestan, it is under the influence of many environmental stresses, which can be mentioned as drought stress and air pollution in the region. The rising trend of the phenomenon of desert dust in recent years has been shown as a danger and its effect on the environmental health and economy of the region is very severe, and the most damage has been reported to the agricultural sector. Although the damage caused by micro-pollens to the agricultural sector is expressed as an economic figure, the effect on plants, especially citrus fruits, remains unknown. Although researchers have studied the effect of fine dust on sugarcane, grapes, legumes, nectarines and peaches in Iran, India and Pakistan, the effect of fine dust on vegetative traits and orange fruit has not been investigated in Khuzestan. Considering that the first step in controlling the effect of air pollution on plants and horticultural crops is to know how it affects the plant, on this basis, the main goal of the current research is to reveal and evaluate the effect of micro-pollens. Desert is on vegetative and reproductive characteristics of Thomson orange in Dezful.

In order to evaluate the effect of desert pollen on the quantitative and qualitative yield of orange fruit, Thomson variety, a field experiment in the form of randomized complete block design with four treatments and three replications was carried out in Dezful in 2018-2019. The treatments included 1) road dust and desert fine dust, 2) desert fine dust, 3) washing after the occurrence of fine dust and 4) control away from fine dust. The chemical and functional characteristics of the trees were measured after applying the treatments, which included chlorophylls a and b, relative water content of the leaves, number of fruits, diameter and weight of the fruit, soluble solids of the fruit and the final yield of the tree.

The results showed that chlorophyll a decreased by 21% and 11%, respectively, in the road dust and desert fine dust treatments compared to the control. Chlorophyll b also decreased to the same amount compared to the control. The diameter of the fruit also decreased by 20% in the desert dust treatment compared to the control. The number of fruits per tree also decreased by 22 and 20% in the treatments of pollen and fine desert dust compared to the control. In the product yield of each tree, in the treatments of road dust combined with desert fine dust and the second treatment, which was only desert fine dust, it decreased by 22 and 17 percent, respectively, compared to the control. Tukey's mean comparison showed that the difference of all quantitative and qualitative characteristics between the treatments was significant and Desert dust has a negative and decreasing effect on the yield of Thomson orange trees; However, washing the trees after the occurrence of micro-pollen removed the effects of micro-pollen on the performance of trees and it even increased compared to the control; So, washing increased the yield of oranges by 40, 35, and 12 percent compared to the first and second treatments of road dust and fine dust, as well as the control.

Plant growth cycle and biochemical interactions of plants show different reactions under the influence of environmental stresses. The results of previous studies indicated that fine dust and dust storms have been identified as an environmental stress for plants that have a negative effect on grapes, medicinal plants, sugarcane, nectarines, peaches and legumes. The effect of fine dust on the plant can be investigated in several characteristics and periods of plant phenology. In the first stage, the deposition of desert fine dust on the leaves of the plant causes shading and reducing the light received by the leaf pigments. Fruit formation is the most important phenological period of the plant, and the occurrence of environmental stress can affect the yield and products of the plant. The present research showed that the number of fruits in orange trees showed sensitivity to desert pollen and the settling of soil particles on orange flowers reduced the amount of fruit formation and finally the number of healthy and ripe fruits in the trees treated with road dust and Desert fine dust decreased compared to the control. Finally, the yield of control orange trees decreased by 17% and 22%, respectively, compared to desert dust and road dust treatment with desert dust. The yield of cotton plants in China decreased by about 28% compared to Desert dust. It can be concluded that although desert dust and road dust reduce the yield of Thomson orange fruit, washing it compensates for the damage and will be economical from the economic point of view.