Showing 15 results for Dust
Toba Alizadeheh, Majid Rezaie Banafsh, Gholamreza Goodarzi, Hashem Rostamzadeh,
Volume 0, Issue 0 (3-1921)
Abstract
Dust is a phenomenon that has many environmental effects in various parts of human life, including: agriculture, economy, health and so on. The purpose of this study is to investigate and predict the dust phenomenon in Kermanshah. Meteorological data with a resolution of 3 hours in the statistical period (2020-2000) of Kermanshah station was obtained from the Meteorological Organization. First, the dust data were normalized and then using ANN neural network models to predict dust concentration and ANFIS adaptive neural network to debug and predict the time series of dust occurrence in MATLAB software were debugged and predicted. Findings showed that the maximum predicted dust concentration related to the minimum fenugreek point with the highest Pearson correlation with dust was estimated to be 3451.23 μg / m3. Also, the results of time series prediction using ANFIS model showed that the linear bell membership function with grade 3, in the training and testing stages, has the most desirable input function among other membership functions. According to the forecasting models, the highest probability of maximum dust occurrence in the next 20 years in Kermanshah was 94%.
Professor Kamal Omidvar, Miss Nesa Sepandar,
Volume 18, Issue 49 (5-2018)
Abstract
In this study, the dust situation in 6 synoptic stations of Kermanshah province was investigated in the period 1987-1992. To study this phenomenon, dust days were extracted in 2009 with code (06) from the current air index. Then data from different bar levels were taken from the National Oceanic and Atmospheric Organization (NCEP / NCAR) database and maps were plotted in the Grads software. Finally, through the processing of MODIS satellite imagery, with the application of the brightness temperature index, round detection and the dust was made and its territory expanded. The results of the study showed that at low ground level, when the European high-pressure system retreated to the north and west, Sudan's low pressure existed in the eastern Mediterranean, and the system moved southwest to the northeast, and when they entered, the disturbance zone is caused due to the lack of moisture in the dust, the main sources of dust in the province of Kermanshah include the deserts of northern Arabia, southern Iraq, and somewhat north of the sub-Saharan Africa.
Yousef Ghavidel Rahimi, Manouchehr Farajzadeh, Esmaeel Lashani Zand,
Volume 18, Issue 51 (7-2018)
Abstract
In this study, the changes in the Khorramabad storm in the period of 1952 to 2015 have been investigated. For this purpose, data from meteorological codes 06 and 07 were received from the Meteorological Organization of the country, and after identifying the days of winding with dust storms and calculating their monthly frequency, monthly, seasonal and annual time series were analyzed. In this study, descriptive statistics, cluster analysis, linear and polynomial trend analysis, and nonparametric Mann-Kendal test were used to study the frequency variation of dust storms in Khorramabad station. The results of the research showed that the monthly frequency of dust storms in Khorramabad station in the middle of May, July and June is May and July, respectively, and from May to July (May to July), the frequency of storms in the dust and dust Khoramabad station is added that this issue is not related to the district heating and dry season. In the seasonal season other than the autumn, which is not frequent with frequent dust storms, in the rest of the seasons, especially in spring and summer, the seasonal concentration of dust storms in Khoramabad has been intensified. The analysis of the trend of time variation in the occurrence of dust storms in Khorramabad station showed that in most of the months of the year and in the three seasons of spring, summer and autumn, as well as in the annual period, there was a significant change in the frequency of dust storms in Khorramabad station. It is increasing with a relatively steep slope, indicating that in the future, the frequency of dust storms in Khorramabad station will be increased.
Dr Amir Karbassi Yazdi, Dr Bahar Beishami,
Volume 19, Issue 54 (12-2019)
Abstract
The aim of this research is to identify and prioritize impact factors of service quality in Tourism Industry. Today, Tourism knows as the most important factors for incoming of countries and Iran is one of the 10th best countries about site seeing. Hence, based on rules, the dependency of Iran’s budget on oil have to decrease. The trip is one of the most important things for each Iranian's family. Therefore, the quality of services in the tourism industry can effect on the quantity of trips. So, these factors must be identified and then the rare resources of travel agencies are allocated to them. One of the evaluation models of service quality is Servqual that has 5 criteria such as reliability; responsiveness; assurance; empathy and tangibles which each of these criteria has sub-criteria. Travel agencies can implement this model and evaluate the service quality of them. But after identification of these factors, allocation of these rare resources such as HR, budget, time for implementing improvement programs is the most important factors for each agency. Hence, for allocating rare resources of travel agencies, Rembrandt method is used. Statistics society of this research is all passengers who travel in other in the internal or external city of Iran during Esfand month. This research is done by survey and sampling did by random. The result shows that among five criteria, sympathy criterion has high priority and among sub-criteria, creating trust in customer has high priority.
Parisa Ahadi, Shahriar Khaledi, Mahmoud Ahmadi,
Volume 21, Issue 60 (3-2021)
Abstract
Dust is referred to sediments of less than 100 microns in size which are transmitted as suspended particles. Dust storms are events which naturally occur in arid and semi-arid areas, especially in subtropical latitudes. One of the most known sources of dust is the west of Asia, including Arabian Peninsula, Syria, Iraq, and Iran, especially Khuzestan Province. The purpose of this study is to investigate the frequency and trend of dust phenomena on hourly, monthly, seasonal and annual scale between 1995 and 2015 in Khuzestan Province. The method in this study is based on statistical computation of dust parameters and also the trend analysis of data based on Mann-Kendall test and spatial distribution maps of dust phenomena. The results suggests that 78.57 percent of dust event are occurred between 9.30 am to 15.30 pm local time, concurrent with peak of sun radiation and earth surface warming, dryness of soil and local pressure difference. The hourly trend analysis is increasing and significant in all hours and the highest increase occurred at 9.30 pm to 12.30 pm.49 percent of dusty days occurred in June, July and May and also 73 percent of them are in spring and summer as following from temperature increase and water and soil resources drying in the province. The seasonal and annual spatial distribution of dust indicates that most of dusty days in all seasons are located in west of province which suggests dominance of external sources as the main source of dust and the importance of topography factor in this area.The Z value spatial analysis suggests high increase of dust event in recent 20 years in southeast, south and central areas of the province and also on last hours of day which demonstrator development of internal sources activities in increasing trend of dust event in recent decades.
Mohsen Saghaei,
Volume 21, Issue 60 (3-2021)
Abstract
Abstract In present century the air transportation has had a very important role in relations between different countries of the world ,as exchanging of culture, showing the economical and military power and speeding the vital affairs of a country and in this case airports form a very critical role in the Air Transportation system An airport is the most infrastructural part of the transportation industry in each country. Therefore, recognizing the problems of this sector of the aviation industry is effective on expediting activities related to the transportation of passengers, the development of the flight network, the growth of the physical airport, reduction in air accidents and problems caused by the proximity to residential areas (colliding with residential areas and noise pollution). In this regard, the aim of the present study is to investigate the problems of Mehrabad International Airport as the most important airport for domestic flights from the aerodrome point of view and the flight network based on standard indices of the national aviation industry. Therefore, among the experts of the aviation industry (pilots, officials and personnel working at Mehrabad Airport), 240 individuals were selected as the sample and a researcher made questionnaire was distributed among them. The application of factor analysis model and SPSS and Lisrel software revealed that the most important problems of Mehrabad Airport are proximity to residential areas, causing noise pollution for residents around the airport, adjacent to the military airport, lack of proper distance from other airports, and its role as flight origin for domestic flights in the Iran’s national airline, totally explain 83.79 % of the common variance. Other variables have not been able to justify significant variance.
Dr. Habibollah Fasihi, Dr. Mohammah Soleimani Mehrenjani, Ms Samira Ahmadnia Koohestani,
Volume 21, Issue 61 (6-2021)
Abstract
Evaluating environmental impact can help urban and regional planner and manager to understand the impacts of development plans on human well-being and environmental health. Therefore, it can enable them to prevent environmental pollution and degradation. This descriptive- analytical research aimed to assess environmental, physical, economic and socio-cultural impacts of Talesh Industrial Estate on Kashli village as the nearest settlement to the estate. Data were collected using a questionnaire. The variables are set in 29 items and were evaluated in 11 ranges by 270 sample people on the basis of a model adopted from Pastakia method. Findings showed that the industrial estate had more positive consequences than negative ones. Positive and negative consequences are more prominent in economic dimension and in environmental dimension respectively. Of the 29 impacts evaluated, the estate has had 16 positive and 13 negative impacts.
Sara Behvandi, Abbas Arghan, Mohammad Reza Zand Moghadam, Zeynab Karke Abadi,
Volume 22, Issue 67 (12-2022)
Abstract
The purpose of this study is to investigate the effect of dust on the economy of Ahvaz. The present study has used descriptive and analytical research methods. In addition, this research is applied-developmental in terms of purpose. The statistical population of the study includes specialists, managers, experts and professors in the field of environment and dust in the city of Ahvaz is 65 people. The sample size was selected based on the total census of 65 people. A questionnaire designed in urban economics in the city of Ahvaz, which has four main variables. Based on this, the questionnaire has 32 questions that will be researcher-made and each of the four main variables has eight questions. Experts and professors formalized the validity of the questionnaire and its reliability was confirmed by Cronbachchr('39')s alpha of 0.81. Data analysis was performed based on structural equation analysis in Smart PLS software. In general, dust has affected the economy of Ahvaz city and this has been in such a way that dust on urban housing with an impact factor of 0.63 and a value of 11.4 T, Dust mites on urban transport with an impact factor of 0.60 and a value of 9.94 T, dust mites on urban facilities and facilities with an impact factor of 0.54 and a value of 6.70 T and dust mites on urban finance with an impact factor of 0.68 and a value of T 16 / 12 has had an impact
Dr Arash Ghasemphour, Dr Azadeh Arbabi, Dr Naser Ebadati, Dr Fatemeh Adibi, Dr Maryam Rostam Pishe,
Volume 23, Issue 69 (7-2023)
Abstract
This research has been carried out with the aim of analyzing and explaining the spatial distribution of Mahshahr port during the years (1981-2021). The research method is descriptive-analytical and practical in terms of targeting. For data analysis, cross-tab, kappa coefficient, sectorial, Heldren and Markov chain models were used. In this regard, Envi 5.3, Terrset, Arc/Gis and Google Map software were used to analyze the obtained information. The geographical scope of this research is the city of Mahshahr according to the census of 2015. Kappa coefficient of Mahshahr port spatial changes map for 1981, 2001 and 2021 is equal to 0.88, 0.94 and 0.94 respectively. The results of this research show that during the years 2001 to 2021, about %75 of the growth of Mahshahr city is related to population increase and %25 is related to horizontal and physical growth. The spreading pattern of Mahshahr port is expanding in the form of clusters in the north, north-west, west and south-west directions. According to the forecast results for the time horizon of 2041, the growth of Mahshahr port will reach from 1657 hectares in 2021 to 2530 hectares in 2041. If there is no optimal management, the dispersal of Mahshahr port and its agricultural lands will undergo many changes in the not-so-distant future, and this will have adverse effects on the residents of this city due to the climatic condition of the city and global warming.
Dr. Ruhallah Moradhaseli, Dr. Ali Bayat, Mrs. Fateme Radmehri,
Volume 23, Issue 70 (10-2023)
Abstract
Aerosol optical depth in 550 nm and angstrom exponent measurements with MODIS have been studied with 1-degree resolution for the period 2006-2017 in the middle east. Moreover, tropospheric aerosol optical depth and depolarization ratios measured at 532 nm with CALIOP have been studied for same area and same period of time too. These parameters have been classified seasonally. Optical depth results show high values for the region especially in spring and summer seasons. During the cold seasons, optical depth values are much less compared with their values at warm seasons. At spring, dust sources located in northern Iraq and those located in central and northern parts of Arabian Peninsula are much more active. Sources located in southern parts of Arabian Peninsula get more active by summer. Angstrom exponent results show that in arid and semi-arid parts of middle east, aerosol sizes are mainly in coarse mode. In arid parts of Iraq and Arabian Peninsula coarse mode particles are dominant during 4 seasons, but for arid parts inside Iran coarse mode is dominant during warm seasons and a modification in suspended particle sizes can be seen during cold seasons. Depolarization measurements of CALIOP show that almost in all seasons, non-spherical particles are ready in middle east atmosphere which is usual for an area inside the dust belt.
Dr Elham Mobarak Hassan, Dr Ebrahim Fatahi, Dr Abass Ranjbar Saadat Abadi, Dr Nasim Hossein Hamzeh,
Volume 23, Issue 71 (1-2024)
Abstract
The Great Khorasan in northeast Iran has a variety of surface structures and plains and high peaks, but due to its vicinity to the deserts of Afghanistan and Turkmenistan, it is affected by dust all the time, especially in summer. The purpose of this study was to simulate summer dust in this region by RegCM model. For this purpose, during the period 2000 to 2017, three extreme dust events were selected. The satellite image used to confirmed dust mass presence and then the synoptic structure was analyzed. Finally, the simulation results of RegCM 4.6 model were compared with the observational data including the horizontal visibility and aerosol optical depth (AOD) of Aqua satellite. The synoptic analysis showed that during the summer, low thermal pressures form in the southern Afghanistan and high pressure in the north. This structure lead to the development of north and northeast winds with speeds of 12 to 21 m / s and dust emission on the eastern border of Iran and western Afghanistan. Investigation of RegCM accuracy done by visibility, Aquas’s AOD showed that model performance in South Khorasan is better as Razavi Khorasan. The highest correlation coefficients of AOD of model and horizontal visibility were obtained at Khorasan central stations including Gonabad, Ferdows, Nahaband and Ghaen at -0.82, -0.77 and -0.44 respectively. RegCM model performed a better dust simulation in severe dust with a horizontal visibility down to less than 1000 m, high continuity and horizontal extension. Overall, the RegCM model underestimates the AOD value for the Aqua satellite algorithm.
Miss Motahhareh Zargari, Dr Mahdi Boroughani, Dr Alireza Entezari, Dr Abbas Mofidi, Dr Mohammad Baaghideh,
Volume 24, Issue 72 (6-2024)
Abstract
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.
Dr Behrouz Sobhani, Dr Mehdi Aalijahan,
Volume 24, Issue 73 (8-2024)
Abstract
Today, fine dust and dust storms have become one of the important issues and problems of Iran and other regions of the world. This study is conducted to identify synoptic patterns of the dust storms in Ardabil Province (Iran) and monitor the origin and pathway of its places. The studied period is 34 years (1979-2013). The data used in this work are from synoptic stations of Ardabil province and the NASA’s upper atmosphere database. To achieve the goals of the study, the Environment to Circulation, Hierarchical Clustering Methods, and HYSPLIT model were used. According to the results, three patterns of geopotential height at 500 hPa levels were identified. Pattern No. 1 and 2 are almost similar to each other and represent the occurrence of a deep trough that formed from Central Europe and extended to the middle of the Red Sea. Based on these patterns, the study area is located in the East of this trough. The third pattern represents the occurrence of cut-of-low pressure blocking over the Black Sea and adjacent areas and placement of Ardabil province in the East trough of the formed blocking. The origin of dust in patterns 1 and 2 is the Eastern regions of Iraq and West of Iran while in pattern 3 is at 500 hPa level of the central areas of Iraq and at pressure levels of 850 and 1000 hPa of the central regions of Syria.
Keywords: Dust storm, Pattern extraction, synoptic analyses, HYSPLIT model, Ardabil province
Dr Sara Karami, Dr Nasim Hossein Hamzeh, Dr Abbas Ranjbar,
Volume 24, Issue 74 (12-2024)
Abstract
Today, dust storms affect the lives of many people around the world and cause a lot of financial and human losses. Every year, Iran is affected by dust storms caused by internal sources and external dust sources located in neighboring countries. Semnan province has several dust-producing sources due to its geographical location, that affect not only this province, but also the neighboring provinces. The purpose of this study is to investigate the dust phenomenon of Semnan province and its monthly changes in the 15-year period, between 2003 and 2017. For this purpose, meteorological stations data of the province and the aerosol optical depth of satellite product have been investigated. Also, GOCART model has been used to estimate the amount of dust emissions from this region and to determine the vertical dust flux in Semnan province. The study of average dust flux showed that the highest values of dust flux was in the southeast of Shahroud and then in the south of Shahroud, Damghan and Sorkheh. A monthly investigation showed that in all months, the average AOD in the southern half of Semnan province was higher than in the northern half. The highest levels of AOD were in May, April and June, and the highest amounts of dust flux were observed in March, June and July. Also, the prevailing wind direction was northeast and northeast, and this factor causes dust particles rising from this region and dust loading in the south of Semnan province and areas of Isfahan, Yazd and South Khorasan provinces.
Tooba Alizadeh, Majid Rezaei Banafsheh, Hashem Rostamzadeh, Gholamreza Goodarzi, Hedar Maleki, Hamzeh Alizadeh,
Volume 24, Issue 74 (12-2024)
Abstract
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.
