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Abed Golkarami, , Afshin Motaghi, Hossien Rabiee,
Volume 18, Issue 49 (3-2018)
Abstract

Knowing Country and understanding the capacity of its perimeter and international environment are essential components of the economy that the foreign policy of any country should be on the basis of territorial and social. The country relies on its geopolitical foundations that they are influenced by its geographical location can affect codification foreign policy in the international economy. Hence, this paper with an analytical -descriptive method to survey the geopolitical and geographical foundations of Islamic Republic of Iran's economy. This paper show that Economy of Islamic Republic Iran away with its Geopolitical foundations and to achieve an effective economic on the closed surrounding and international environment, review in Geopolitical foundations of foreign policy that is mentioned in the form of five components are necessary and is inevitable. Hence, Islamic Republic of Iran to pursue these foundations in foreign policy strategy, not only effects will be in terms of political and cultural on international environment but also in terms geo-economic impact on international political economy.

Mrs Faranak Bahrami, Mr Abbas Ranjbar.s.a, Mr Ebrahim Fattahi,
Volume 18, Issue 50 (3-2018)
Abstract

Probable maximum precipitation (PMP), is the highest rainfall, which occurs at a given time in a basin. Hydrologist calculates the probable maximum flood for the design of overflow dams, by using the PMP, with two methods: statistical and synoptic. The purpose of this study is calculating PMP in the Ghomrood basin by using the synoptic method. For this purpose rain, meteorological data of the Iran’s Meteorological Organization were used. Also, the data on the 850 and 500 hPa levels were analyzed by the National Center for Environmental Prediction and the National Center for Atmospheric Research (NCEP-NCAR). In the following, the required synoptic maps produced and were studied. Iso rain maps were drawn, and depth-area-duration curves were determined. Eventually, PMP was estimated at 24, 48 and 72 hours. So that 24 hours PMP, by calculating 50 and 100 years return period of dew point estimated 51/75 and 54 mm respectively. Also for 48 hours PMP 128/25 and 132/05 mm, and for 72 hours PMP 97/9 and 101/75 estimated.

Mohammad Daraei, Dr Peyman Mahmoudi, Dr Behroz Sari Sarraf, Dr Ali Mohammad Khorshiddost,
Volume 18, Issue 50 (3-2018)
Abstract

Agricultural sector is most dependent on climate, and climate is the main determinant of time, location, production resources, and productivity of agricultural activities. The first event of zero-degree temperature in fall and its last event in spring is important for agriculture. This information is used to determine the species suitable for planting in each area. The present study seeks to identify the probability distribution function for extracting statistical characteristics of frost events in Iran. For this purpose, the history of early autumn and late spring frosts were extracted using daily minimum temperatures of 44 synoptic stations in Iran for a period of 30 years (1981-2010). After fitting various distributions, the best distribution was selected using Anderson-Darling goodness of fit test. Results indicated that most stations follow the Wakeby distribution. Based on the calculations, the first day of frost occurs in the highlands of the Northwest (Saqez, Hamedan, Ardabil, and Zanjan), Northeast (Bojnoord, Torbat-e Heydariyeh, Birjand, and also the Central Zagros Mountains (Shahr-e Kord), due to proximity with cold lands of the North such as Siberia and Northern Europe as well as early entry of westerly winds to this region compared to other regions of Iran will occur. And the latest event of the first day of frost occurs a little farther from the southern coast of Iran in a narrow strip along the coast and parts of the northern coasts (from Babolsar to Bandar Anzali). The earliest event of the last day of frost occurs in the same area in early February. The latest day of frost in Iran occurs in Azerbaijan, Kurdistan, Khorasan, and highlands of the province of Chahar Mahal and Bakhtiari

Sayad Asghari Saraskanrood, Zeynab Dolatshahi,
Volume 18, Issue 50 (3-2018)
Abstract

The purpose of this research is to evaluate the quality of wine in Khorramabad city as a major issue in public health and health management of citizens. To perform this research, data on the chemical element of 23 wells and fountains in Khorramabad County during the period of 2002 to 2013 were presented in the form of a series of elements: fluorine (F), calcium (Ca), magnesium (Mg), potassium (K) The ArcGIS software and the algebraic or deterministic internalization methods, geology, IDW method, Kriging method and splint method were used for mapping and drawing maps. To assess the chemical quality of the drinking water element, standards were used: the National Standard, World Health Organization (WHO) and the United States Environmental Organization (EPA) as an indicator of pollution. The results showed that the amount of calcium (Ca) in all seasons and in all sources is lower than the national standards (WHO) and (EPA) standards, but in some sources higher than the standard desirable standard. The amount of fluorine (F) only in the spring and summer is higher than the standard standard (EPA) in some wells, but in winter and fall in all wells and springs above the standard desirable standard (EPA) is. And the amount of potassium element (K) in any of the seasons and in any of the wells and springs is higher than the desirable and desirable national standard, WHO and EPA, as well as a handful of magnesium (Mg) in none of the water sources studied It has not been higher than the national standard, (WHO) and (EPA).

Mrs Masooume Darmani, Mohammad Nohtani, Haydeh Ara, Ali Golkarian, Salman Sharif Azari,
Volume 18, Issue 51 (6-2018)
Abstract

One of the most important processes of erosion and sediment transport in streams is the river most complex engineering  issues.this process special effects on water quality indices, action suburbs floor and destroyed much damage to the river and also into the development plans  Lack of continuity sediment sampling and measurement of many existing stations. due to the low number of hydrometric stations in Iran and the lack of continuity of sediment sampling and measuring in many existing stations, on one hand the exact amount of sediment load in many rivers in the country is not available and because of differences in climatic, hydrological and topographical conditions in the country, on the other hand, the preparation and calibration of sediment Erosion Models different regions, is unavoidableCalibration models of erosion and sedimentation in different locations is difficult and requires financial capital andthe time . the But evolutionary optimization algorithm able to resolve this problems of mathematical and experimental methods in this paper, a new optimization algorithm spiders can be made to education And the evolutionary pattern for input (discharge and precipitation) and rain-gauge gauging stations and Watershed Kardeh designated evolutionary algorithms and artificial network performance for 24 year 24-year dam catchment Kardeh for the period studied. In conclusion, the results proved that social spiders optimization algorithm t better resultspredic to for sediment in watershed Kardeh


Mostafa Karimi, Mahnaz Jafari, Faramarz Khosh Akhlgh, Saeed Bazgir,
Volume 18, Issue 51 (6-2018)
Abstract

Spatio-temporal variations of factors affecting the occurrence of precipitation can lead to a change in its amount. The atmospheric moisture is one of the most important factors for precipitation formation. In this study, changes in atmospheric moisture and its relation with occurrence of seasonal wet and dry periods were investigated in Iran. The re-analysis data from the ERA interim European Center for Mid-Term Projections (ECMWF) was used during the period 1981-2011. The z index (ZSI) was used to extract wet and dry periods of autumn, winter and spring seasons. The seasons with the maximum percentage of wetness/drought occurrence during the above periods were selected. Vertical integrated divergence of the moisture flux was extracted in three layers of the lower, middle and upper atmosphere above Iran. The results revealed that in all three layers, moisture flux was maximum during wet period and decreased in dry one. In all layers in wet and dry periods, the moisture content imported to Iran increased during warm season as compared to cold seasons. In addition, the difference in moisture content in the warm season was less than cold seasons and has less variations. There was no significant changes in moisture at high levels in three seasons. In general, there was a significant difference in terms of the winds pattern in the wet and dry periods. The favorable conditions of flow patterns on the water surface of the region provide the condition for increasing transport of moisture to Iran. Although, the moisture transfer reduced due to deviation and change of direction of currents, in dry period especially in the lower layer, and hence increase the occurrence of dry periods in Iran.

Rahmatollah Shojaei Moghadam, Mostafa Karampoor, Behroz Nasiri, Naser Tahmasebipour,
Volume 18, Issue 51 (6-2018)
Abstract

The purpose of this study is to analyze and analyze Iran's precipitation over the past half-century(1967-2017). For this purpose, the average monthly rainfall of Iran during the statistical period of 50 years was extracted from Esfazari databases (Which is provided using data from 283 stations of Synoptic and Climatology). Regression analysis was used to analyze the trend and to analyze the annual and monthly rainfall cycles of Iran, spectral analysis was used. Investigation and analysis of monthly precipitation trend indicates that except for central Zagros (Lorestan and Chaharmahal va Bakhtiari and Gorgan areas, where rainfall in winter season has increased trend), in other parts of the country and in other seasons, the trend of decline Precipitation is prevalent. The study of Iranian rainfall cycles has been shown  that Most of Iran's rainfall cycles are 2 to 4 years old and have a short term course. Meanwhile, there are two middle-cycle 25-year cycles in January-July and two long-term 50-year cycles in March and December, indicating a trend in the March and December rainfall. The two months of February and October lacked a clear cycle. The analysis of the auto-correlation model of rainfall showed that the high spatial auto-correlation model in winter was consistent with the western, southwestern and coastal of the Caspian Sea and covered about 14% of the country's. The low spatial auto-correlation model is found in sparse spots in the southern, central and southeastern regions of the country in winter and spring, and covered about 7.5% of the country's. The results of this study indicate that the overall trend of Iran's rainfall is decreasing trend and only in winter, in the small regions of the country, the increase trend is observed.

Hossein Imani Pour, Abdolreza Kashki, Mokhtar Karami,
Volume 18, Issue 51 (6-2018)
Abstract

Heating requirements are one of the most important human issues in the fields of agriculture, tourism and energy management in the present and future .Knowing the extent of these changes can be very effective in making decision makers. The purpose of this study is to examine the changes in the requirements of the heating degree day in conditions of climate change in southern Khorasan province. For this purpose, daily data from the minimum and maximum temperature of 11 stations of the South Khorasan province were received from the Meteorological Organization of Iran during the period of 1990-2015. The latest available scenarios of the fifth report of the Climate Change Interagency Panel (AR5 2014) include RCP scenarios from the Canadian Climate Change website and, using the SDSM macroeconomic statistics software, the data for the upcoming period (2016-2046) in the study area was thrown off. Using the Matlab software capability, the monthly and annual heating requirements of the stations were calculated in the current and future period. Finally, using the Kriging interpolation method, the zoning maps for cooling requirements for the current and future period are mapped in ArcGIS software. By examining the effect of geographic features (latitude and longitude and station height) on the heating needs in the area, it was determined that the role of heights is very effective in changing the heating needs. In the cold months of the year (Azar, Dey and Bahman), the highlands (Qain, Arsak, Fath Abad, Aryan Shahr, Darmian) require higher energy levels due to the need for higher temperatures. Increasing the temperature and warming of the air in the future, especially in the months of Farvardin and Mehr in most places, requires less use of exhaustible equipment in the future.

Yousef Ghavidel Rahimi, Manouchehr Farajzadeh, Esmaeel Lashani Zand,
Volume 18, Issue 51 (6-2018)
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 Vahid Riahi, Dr Parviz Zeaiean Firouzabadi, Dr Farhad Azizpour, Ms Parastoo Darouei,
Volume 19, Issue 52 (3-2019)
Abstract

The cognition of cropping pattern is important for planning and resource management .Remote sensing as a science and technology of spatial information and geographic information system due to having the analytical facilities can play a key role in determining the distribution of crops and their lands under cultivation. In this research, in order to identify and separate the lands under cultivation of the dominant crops in Lenjanat of Isfahan province, the multi-temporal images of Landsat 8 satellite, OLI sensor were used in the dates of April 17, July 6, and August 23 in 2016. Using maximum likelihood classification and normalized difference vegetation index (NDVI) of the agriculture crops in different periods of growth and according to their cropping calendar, the map of the cropping pattern of the area was determined. To evaluate the accuracy of the results, the produced maps were examined with reference data. Kappa coefficient and overall accuracy were 0.88 and 90%, respectively, in maximum likelihood classification, and 0.90 and 93%, respectively, in NDVI. Furthermore, statistics presented by Agricultural Jihad Organization of Isfahan province in the 2015-2016 crop year was used for evaluation. The results showed that there were differences equal to 10.2%, 18.6% and 1.8%, in the area under cultivation of wheat and barley, rice, and potato and forage, respectively, in maximum likelihood classification, comparing with the statistics of Agriculture Jihad while the results of NDVI comparing with Jihad statistics showed the errors equal to 6.6 %, 6.5 % and 3.2%, respectively, that indicated the better performance of temporal vegetation indices in estimation of area under cultivation according to its phenology. Investigation of land use and cropping pattern of this area indicate a high centralization of agricultural lands with high water requirements and industries on the proximity of Zayanderud River which necessitates the spatial analysis of land use in this area.


Dr Amjad Maleki, Dr Sajad Bageri, Master Sara Mataee,
Volume 19, Issue 52 (3-2019)
Abstract

Vulnerability assessment and mapping of hazard pollution is raised on as an important management strategy to protect the karst. Karstic aquifers in semi-arid regions of the West of Iran with regard to the natural conditions of the region, are susceptible to contamination. Estimation of amount and vulnerability mapping of aquifers in the karst religion of Bistoun- Paraw – Kermanshah plain against poullution emissions using the COP model are theaims of this study. This model using of three parameters - covering layer (O), concentration of flow (C) and regime of precipitation (P) - assesses the vulnerability of karst water resources against pollution. The results show that %31/4of the area has located in the zone of average vulnerability and %30/7of area has been in the low ​​vulnerability area and %37/9of the area has taken a very low vulnerabilities value. The later zone has been included  most part of the plain. Major areas of low and moderate vulnerabilityzones has been located in the high part of the area on wherethe developed limestone territory of karst formations is found. Vegetation cover of these regions areforest-steppe vegetation where is located in the low vulnerability zone and without vegetation cover where is in the moderate vulnerability zones. The latest has over 800 mm Precipitation. Totally, the Parameters that have  most important role in  vulnerability level in the areaare C, P and O respectively.
 
 
Mrs. Mina Ranjbar Fard, Ms. Hourieh Aarabi Moghaddam,
Volume 19, Issue 52 (3-2019)
Abstract

Nowadays almost all big cities are confronting heavy traffic and suffering from lack of parking lots which leads in traffic jam. According to the significant role of vertical parking in reducing the traffic load and smoothing the traffic current; this study was carried out with the purpose of presenting a decision support system for vertical parking site selection for mechanical and constructive parking lots by using Fuzzy-DANP method. Each criterion’s correspondent GIS data was acquired from Tehran Municipality for district no.3, 6, 7, 10, 11 and 17 which were chosen according to the corresponding mayors’ opinions of those districts and converted into its specific layer. Each criterion’s weigh was exerted to its determined GIS layer and eventually all those layers were integrated with each other. The final map of GIS output demonstrated a spectrum which determined the most appropriate to inappropriate locations to establish a parking of each type. The final results were shown within a user interface, including the GIS map and the estimated location of the chosen district and parking type. The overall steps mentioned above are forming the DSS of the study. The results showed that setting up mechanical parking in districts no. 3, 6 and 7 is proper. For building constructive parking; all districts are appropriate.

Mr Abdall Hassan Shivaey, Dr Asghar Zaraby,
Volume 19, Issue 53 (6-2019)
Abstract

The first step in designing effective programs that are consistent with realities and attaining transcending goals is to develop balanced, proportionate and balanced knowledge and knowledge of the capacities and capacities of each geographic region. Hence, the recognition of the status quo of the regions is inevitable. The purpose of this research is to measure the urban areas of Kohgiluyeh and Boyerahmad provinces and determine the priority of development in each city and each factor. This work was carried out using 84 different combinations of spss components into 8 factors: employment and activity, housing, economic - production, transportation and communication, public utilities, health care, books and literacy and education related to the statistics of 2011 , Using two techniques: a combination of Human Development and Mauritius, and integrating their results into a merger technique. The research method is analytical-descriptive. The statistical population of the research is urban areas of seven provinces (16 cities) of the province. The findings of the research indicate that Boyerahmad, Dena and Gachsaran cities were developed in the first to third grades and the Bahmei city was at the last rank of development of the province, and in the study of all factors individually, Was deprived of the last rank, and the counties of Saram, Kohgiluyeh and Basht were deprived of the level of development and were slightly better than Bahmei, which is why the Bahmei city should be placed in the first priority for development planning.

Elham Yarahmadi, Mostafa Karampoor, Hooshang Ghaemi, Mohammad Moradi, Behrouz Nasiri,
Volume 19, Issue 53 (6-2019)
Abstract

Investigating of rainfall behavior in the spatial-temporal dimension and determining the tolerance thresholds of different geographical areas with respect to vegetation, animal life and human activities, is essential for any decision in the environment. Therefore, precipitation data of 27 stations were received from the Meteorological Organization during the 60-year period and After the data were evaluated qualitatively, The distribution of temporal and spatial mean, coefficient of variation, skewness and probability distribution of 20% maximum and minimum monthly and seasonal autumn and winter, for a period of 60 years (1951-2010), two 30-year periods (1980-1951), (1981- 2010) and two 10-year periods (2010-2001), (1951-1960) were calculated  and were zoned using GIS. Studies show, except on the shores of the Caspian Sea, there is little change between autumn and winter patterns. The average rainfall of the southern shores of the Caspian Sea has decreased to the west and east. in other areas of the country, the spatial and temporal variations of rainfall in the autumn are very highand from the north to the south, the mean decreases and the coefficient of variation and skewness increase. In winter, maintaining the pattern of autumn, the average precipitation increases and the coefficient of variation decreases. The average precipitation of 30 years and 10 years of the second winter season, compared to the first 30 years and 10 years, and also the 60 year period, has decreased in most stations, which is consistent with the results of the Mannkundal test. Analysis and review of the 20% minimum and maximum seasonal rainfall show that the intensity and range of performance of winter precipitation systems in the second 30 years have decreased. Also, the frequency and severity of drought in the autumn season have increased in the second 30 years and in the last 10 years. The highest decline occurred in the western and eastern parts of the Caspian coast and in the northwest, which requires special attention to managers in light of the areas of activity and concentration of the population.

Reza Khoshraftar, Gholam Hassan Jafari, Mehdi Feyzolahpour, Habib Arain Tabar, Parvaneh Moradi,
Volume 19, Issue 54 (9-2019)
Abstract

In this research, due to the abundance of tectonic and karstic structures in the Prav Bisotun region, the relation between fault building and karstic springs was evaluated. To do this, we first prepare information layers including the location of the springs, the location of the closed holes, faults, the slope and the elevation floor layer, and then the graph of the grains of the faults is drawn and weighted by the weight of the evidence Was investigated. Investigation of the relationship between springs and faults in the Prav Bistuon region using the weighted method showed that there is a close relationship between tectonic elements and the frequency of springs, so that at low distances of the faults, the number of springs more and with The distance from the fault, the number and frequency of springs, is reduced. Also, the results of diagrams showed that faults have a direct effect on the origin and orientation of the springs. In the study of the relationship between the slope and abundance of springs, it was found that most of the springs were located on a gradient of 0 to 5 percent and elevations of 1200 to 1400 meters. The above altitudes cover the mountain slopes.
 


Zahra Tarasi, Hosin Karimzadeh, Mohsen Aghayari Hir,
Volume 19, Issue 54 (9-2019)
Abstract

While women account for about half the population of rural areas, they have always been considered as vulnerable populations of the community. Considering empowerment and its effective factors can increase their participation in livelihoods and increase their ability to help increase their family income. Therefore, the aim of this study was to investigate the factors and drivers that affect the empowerment of rural women. The present research is a descriptive-analytical one. The data gathering tool was a questionnaire and interviewed with rural women in Zanjan. The statistical population includes rural women in Zanjan city (N = 43559). Using Cochran's formula and quotient sampling, 381 women over 20 years old were selected as samples. Data were analyzed using one-sample t-test and binary logistic regression tests. The results showed that among the 29 variables in the study, 14 variables significantly had a significant relationship with the empowerment of rural women in Zanjan. Accordingly, economic factors (0.1171), psychological (0.197) and personal factors (109.10) had the most effects on empowerment of rural women (dependent variable). The results of this study can be used to identify the factors affecting the empowerment of rural women and removing the barriers related to it in the villages of the region and in general in the villages of the country.
Arash Sadri, Arezu Bankian Tabrizi, Shadi Refaei Afsharghezelbash,
Volume 19, Issue 54 (9-2019)
Abstract

This article was written with the aim of the pedestrian impact on increasing social interactions in urban spaces of Bojnourd, with emphasis on social dimensions of social interaction. The method of this research is descriptive-analytic, which first of all has been designed to identify theoretical perspectives, general criteria of environmental quality and then collect field data and interviews with residents. Data analysis was performed using SWOT method. Case study is Taleghani street of Bojnourd. The results showed that the effect of physical properties on the quality of urban environments is in the first priority. Then, perception of the environment in the second priority and functional characteristics are in the top priority. According to the results, the most important independent variables in these three categories (physical, cultural and environmental) (security priorities, accessibility, passages, economic functions, urban environment, quality of social environment, social interactions Cultural activities, urban amenities, and recreational and lighting functions have the least impact.

Msc. Graduated Student Najmeh Daneshvar-Marvast, Dr Somayeh Soltani-Gerdefaramarzi, Dr Samaneh Poormohammadi,
Volume 19, Issue 55 (12-2019)
Abstract

The phenomenon of evapotranspiration causes water and moisture losses from water, soil and vegetation levels. Due to the small amount of atmospheric precipitation and water resource constraints in Iran, it is important to calculate it through a suitable method. The present research attempts to evaluate the evapotranspiration reference crop (ETo) and present it in the form of zoning map as a basic tool for water management. In this study, the long-term average of seven meteorological stations and evaporation pan data were used to determine the appropriate ETo estimation method. Evapotranspiration of reference crop was calculated to 14 methods the based on climatic information in each station. Computational methods including combinational methods Penman-based, radiation-temperature method, temperature method and radiation method. The most appropriate computational method was selected based on the R2 and Nash -Sutcliffe statistics. The zoning of evapotranspiration of reference crop was carried out based on the geographic information of the meteorological stations and the GIS software. The results of the research indicate that the best method for this region as the cold and moderate climate are FAO radiation and Blaney-Criddle. Also, the zoning result shows that west of the catchment has less evapotranspiration rather than its east. Sunshine hours, maximum temperature and wind speed were the most effective factors for evapotranspiration in this area by sensitivity analysis.

Hosseinali Roohbakhsh Sigaroodi, Mostafa Karampoor, Hooshang Ghaemi, Mohammad Moradi, Majid Azadi,
Volume 19, Issue 55 (12-2019)
Abstract

Investigating the variability of the spatial-temporal pattern of rainfall, which can lead to climate change, due to its strong impact, is of interest to various scientists. For this purpose, after receiving the daily precipitation data of 27 stations for the period of 60 years (2010-1951), its quality and the total monthly precipitation and statistics necessary for the continuation of the research process such as mean, coefficient of variation, skewness, probability estimate of 20% The upper limit of the maximum and minimum rainfall average were calculated experimentally for a period of 60 years and two 30-year periods (1951-1980 and 1981-2010) and two periods of 10 years (1951-1960 and 2010-2001) for each of the spring and summer seasons Was calculated. The studies show relatively modest variations in spring and summer precipitation patterns on the Caspian coast, Northwest-West, 30 and 10 years old, compared to the 60-year, 30-year, and 10-year periods. In general, the mean of precipitation decreases from north and northwest to south and south east and increases the amount of coefficient of change and skidding. Except for the Caspian Basin, in the remaining stations, the average spring precipitation is higher than the average summer rainfall. There is a clear difference in the long-term characteristics of precipitation and its changes. It is worth mentioning that the increase in the coefficient of variation of the 30-year and 10-year periods is comparable to the corresponding periods at all stations, which indicates a decrease in the monthly and seasonal mean of spring and summer precipitation, which confirms the results of the decade and the first decade of the second decade. The greatest decrease occurred in the northern and western parts. In the second 30 years, the incidence of dry sunshine and drought-affected stations has increased. Therefore, it confirms the climate change for the Caspian and the Southwest coast.

Dr Dariush Yarahmadi, Dr Amanolah Fathnia, Mehdi Sherafat,
Volume 20, Issue 56 (3-2020)
Abstract

Abstract
The extention of Snow cover and its spatial and temporal changes considered as a basic parameter in climatic and hydrologic studies. Data from satellite images due to the low cost and the large extention of cover are, effectively help the identifying of the snowy basins. Since the satellites are able to imaging a surface at different times, this will allow snow survey studies to investigate the spatial and temporal distribution of snow. In this research, Snow line changes and the surface temperature line in Alborz Mountains using NOAA-AVHRR satellite images since 2006 from 2015 was studied. The results showed that at the study period, maximum area of snow have been observed in April 2015, with the amount of 12051 square kilometers and the minimum area snow have been observed in June 2008, with the amount of 33 square kilometers. The average of the lowest elevation of snow covered areas, have been observed in April 2007, with the amount of 2662 meters and its highest value have been observed in June 2008 with the amount of 3820 meters. Also the most of the snow line change occurred between the years 2007 to 2008. Moreover, in almost of 15 years, the isoterm of zero degrees Celsius, matches with the snow line and its elevation has changed as the snow area is changed.
 

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