Showing 84 results for Ira
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Volume 16, Issue 42 (9-2016)
Abstract
In Iran the issue of occurring natural disasters, particularly mesoscale convective systems. They are important on one hand, because of their increasing intimidations and causing damages and on the other hand, because of their increasing abundance, time of duration, and happening. Therefore life cycle, constituton condition and mesoscale convective systems features in west of Iran using satellite and extention area index and thresholds of brightness temperature 221 and 243 K have been studied. After their statistic analysis, based on mesoscale convective system importance, life and daily cycle, behavior parameters, and synoptic conditions of this system life cycle were analysed. Most of the systems have been formed in southeastern Iraq and in western Zagros hillsides. Wile puberty stages (the maturity) and their expandings were increased with the height increase; in turn, declining of the systems began by passing Zagros chain mountains. The system extention area at the system life cycle starting increases with a smooth process; whereas the reduction process of the system extention area at the declining stage was severe and sudden.
Mohammad Hassan Yazdani, Ali Soltani, Hossein Nazmfar, Mohammad Amin Attar,
Volume 16, Issue 42 (9-2016)
Abstract
Urban segregation has been a problem of many cities of the world. Many researchers have interested in the urban segregation issues. Urban segregation has strongly concentrated poverty and created underclass. Different types of urban segregation exist, including income and racial or ethnical segregation, and depending on the contextual mechanisms within a city. To understand and plan a better community, urban planners needs to know how to measure the segregation and interpret the results. There have been many developments of segregation measures. Some evolved and some remained unchanged. This paper is studied the most used multigroup measures of residential segregation (8 indicators) in Shiraz city and between different socio-economic groups of it by using of the Segregation Analyzer Software. In general, the results show the occurrence of segregation in the medium amount to the high amount and by the calculated values of 0/7177, 0/5785, 0/5474 – 1, 0/5407, 0/3969, 0/3759, 0/3613, 0/3375 in the city of Shiraz. On the other hand, the use of Hot spots Analysis in the study area shows that the greatest concentrations of the socio-economic high group are in almost near the center of Shiraz city and the northwest of city, and for the socio-economic medium group exists in the west of city. Also there is the greatest concentration of the socio-economic low group in the southwest of Shiraz city.
Kamal Omidvar, Reza Ebrahimi, Mohammad Kykhsrvy Kayani, Ghasem Lkzashkoor,
Volume 16, Issue 43 (12-2016)
Abstract
The aim of this study was to investigate the effects of global warming on where the slope changes when the monthly temperature in Iranian territory over the coming decades (2050-2015). The simulated temperature dynamic model EH5OM subset Hybrid Models atmospheric circulations (GCM) selection and data model of the Center for Theoretical Physics Salam (Italy) were derived from emission scenarios A1B scenario was chosen given the scenario of 2100 -2001 found that from 2050 to 2015 were used in this study data is then output the data in the fourth edition of the regional climate model (RegCM4) Linux environment was fine scale output data Downscaling model with dimensions of 27/0 * 27 / Degrees latitude is where the dimensions of 30 x 30 km area of approximately cover the average temperature of the matrix deals 13140 2140 * was extracted. Finally, the slope of the average monthly temperature during the period under study by Mann-Kendall slope age and matrix computation in MATLAB software 13140 * 12 respectively. Results show rising temperatures in March and April to June, more than 90% of the country, that it will be spring's warmer. Increasing the temperature in the winter months and spring mountainous parts of the western half of the country is warming the cold regions of Iran. Temperature negative trend in October and November in the northern part of the eastern half of the region's countries could be indicative of colder temperatures in the northern West.
Dr. Morad Kavianirad, Dr Yadollah Karimi Pour, Dr. Hedayat Fahmi, Mr. Sadegh Karami,
Volume 17, Issue 46 (9-2017)
Abstract
Efforts to provide security have always been of great importance to human being. In recent decades, the security issues of climate change have attracted attentions due to its sustainable consequences on the lives and civilization of humans. Among all countries, the ones which are placed in draught belt, like our country Iran, have hurt a lot because of low precipitations and also mismanagements in water resources control. Climate change show itself by changes in precipitation patterns, reduction of precipitation and increasing of temperature. According to the present data, Iran's central drainage basin which consists of important geopolitical provinces, has been affected by the above mentioned factors. This descriptive-analytic research is carried out based on the effects of climate change on Iran's central basin which provides approximately 48 percent of Iran’s GDP. Continuity of climate changes in this region can make critical problems in social, environmental, economic and political scales and the lives of the citizens would be affected as well. To conclude, the persistence of the current conditions in climate change in the central drainage basin of Iran, would result in challenges through the national stability and security.
Dr Zahra Hejazizadeh, Mr Meysam Toulabi Nejad, Mr Alireza Rahimi, Mrs Nasrin Bazmi, Mrs Atefeh Bosak,
Volume 17, Issue 47 (12-2017)
Abstract
The aim of this study is modeling spatiotemporal variations of albedo. This study was conducted using simultaneous effects of several components, such as wetness of surface layer of soil, cloudiness, topography and vegetation density (NDVI), using MEERA2 model with a resolution of 50 in 50 km during 2000-2010 in Iran. The results of spatial analysis of albedo values in Iran showed that the highest value is in 44 to 45 degrees of east longitude about 2.8 to 3.3 and the lowest value of albedo is also in 52 to 53 degrees of east longitude, that is, the eastern slopes of the Zagros Mountains, have been recorded at 1 to 1.5 units. In terms of provincial rank, the largest albedo is about 0.25 units in Ilam province and the Fars province is ranked next about 0.24 units. The lowest amount of albedo also in the Gilan provinces and in next Mazandaran province are about 0.19 and 0.18 respectively. In addition, the results of temporal analysis in seasonal scale showed that the highest albedo in Iran in winter was 0.26 and its lowest amount was recorded in spring with 0.23 units. In general, according to the factors used, it can be said that the western and central parts of the country have a highest albedo, and the north and northwest regions of the country have a lowest albedo.
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Volume 18, Issue 48 (3-2018)
Abstract
In the current disorderly world, securing benefits and achieving optimal security for countries alone is very difficult and unavoidable. Uniting with other countries and powers is a way to advance national goals and provide benefits, and bring more guarantees for countries to survive, advance, develop and peace. The factors and conditions that lead to the unification of the countries have been a lot of controversy and debate and have been analyzed from a variety of perspectives. Although geographic proximity and geographical similarity seem to be the prelude to creating unity between countries, the Iranian-Iraqi model in the Middle East is challenging this claim. Except for a few days in the early 20th century, the two countries were in conflict with the majority of the century, even an eight-year-old war between them. So the main question of this research is how geopolitical factors contribute to the unification of countries, and what are these factors and components in the strategic relationship between Iran and Iraq? This research is descriptive and based on library and document data. The results of the study show that the components of the internal environment (economic, socio-cultural components, geographic and political components, security and geopolitics), the regional external environment and, ultimately, the global environment have affected the quality and quantity of the strategic linkage of Baghdad-Tehran. The strategic link between the two countries is a function of the accompaniment and positive function of the triangle, which itself is based on more complex components.
Fatemeh Ghiasabadi Farahani, Faramarz Khoshakhlagh, Aliakbar Shamsipour, Ghasem Azizi, Ebrahim Fattahi,
Volume 18, Issue 48 (3-2018)
Abstract
The present research about the spatial changes of precipitation is mainly focused on western areas of Iran. Precipitation data for three seasons of fall, winter, and spring have been obtained from Esafzari Database, with 15*15 km spatial resolution in the form of a Lambert Cone Image System for the period from 1986 to 2015. To examine the prevailing pattern of precipitation in west of Iran, we have used geostatistical methods of spatial autocorrelation. The changes in precipitation trends have been analyzed using parametric and non-parametric analyses of regression and Mann Kendal. We have used MATLAB for analysis of the data. We have also used ArcGIS and Surfer for drawing maps. The results of inter-decade changes of positive spatial autocorrelation of precipitation in west of Iran have indicated that there has been a decline in spatial extent of the positive spatial autocorrelation pattern in spring and fall, except for winter with a negligible increasing trend. Nevertheless, except for the second period, no considerable spatial changes were observed in the spatial pattern of precipitation in the region. However, there was a decreasing trend in the negative spatial autocorrelation of precipitation in annual and seasonal scales. The results of trend analysis have indicated that there was a decreasing trend in a vast area of the west parts of the country in annual scale and also in winter. Although there was an increasing trend in precipitation in fall and spring, but the trend was not significant in 95 % of confidence interval. The results of Man Kendal test have confirmed the results obtained from linear regression.
Fakhri Sadat Fateminia, Behrouz Sobhani, Seyed Abolfazl Masoodian,
Volume 18, Issue 48 (3-2018)
Abstract
This study was performed to evaluate the extent of leaf area in Iran from (2002) to (2016) using Remote sensing. For this purpose, we extracted data collection and leaf area index for the Iranian territory from MODIS website. The database was established with programming in MATLAB software to perform mathematical and Statistical calculations repeated. After the analysis of the data in this software a monthly average long-term map was developed. The maps show that the central, East and South-East are almost empty of leaf area or seen very sparse in some areas. In contrast areas of leaves in the northern and western parts of Iran, are good, which generally includes fields, except forest Arasbaran and Hirkany. Precipitation and the temperature, is the main factors for the growth and development of plants, that these two conditions are enumerated in the west due to being on the way of westerly winds. Lowest leaf area index is for January and February and the highest average of leaf area is for May and June. Next, study of 15 years of leaf area index data by cluster analysis based on the calculation of Euclidean distance and Ward method, showed that all 12 months fit in the two main groups and, in fact, divided for two periods of strong and weak vegetation. In this analysis, , April during the cold period and October in the warm period of the year as the transition months and they are located on a separate cluster
Hasan Zolfaghari, Jafar Masoompourv Samakosh, Shabnam Chahvari,
Volume 18, Issue 49 (3-2018)
Abstract
The purpose of this study is predicting climate changes and investigating the effect of probable climate change on the growing degree-days in the northwest of Iran. For this purpose the climatic data of seven synoptic stations during a 25 years period (1985-2009) was collected including Oroomieh, Tabriz, Zanjan, Sanandaj, Ghazvin, Kermanshah, and Hamedan were used as the base period and thus temperature variations periods (2030-2011 and 2065-2046) through HadCM3 model was simulated. For the little power of temporal and spatial distinction of this model, its outputs were downscaled using LARS-WG software and presented under Emission Scenarios including A1B (moderate scenario), A2 (maximum or pessimistic scenario), and B1 (minimum or optimistic scenario). Calibration, verification and Performance Model with the rate of the adaption of observed data and the simulated measures through statistics , RMSE and MAE were analyzed. Finally, using the simulated temperature growing degree-day was calculated and compared under 4 Base temperature including 0°,5°,10°, and 15° centigrade in the basic span (1985-2009) and future span (2011-2030 and 2046-2065). The results of simulation show that temperature change in north-west areas under all three A1B, A2, and B1 scenario are increasing in the future, but the differences among these three scenarios in each period is inconsiderable. In total the most temperature increasing was detected as 0/7 centigrade in A2 scenario for 2011-2030 period and 2/3 centigrade under A1B scenario for 2046-2065 period. Generally with the temperature increasing, the amounts of growing degree-day without exception increases in review periods and under the four Base temperature. Under studied scenarios, the Bases temperature of 0° centigrade had the most and 15° centigrade had the least impressibility from climate changes, so that the most increasing in calculated degree-day measures under 0° and 15° centigrade bases in the first period to the basic scenario (1985-2009) respectively was simulated as 207/4 and 120/6 degree-day under A2 scenario and for the second period to the 752/5 and 463/5 degree-day under A1B scenario.
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.
Hossein Asakereh, Robab Razmi,
Volume 18, Issue 50 (3-2018)
Abstract
In the present study, the main aim was the spatial evaluation summer rainfall of northwest of Iran based on30 stations in northwest of Iran during 30 years of statistical period (1985-2014). An attempt, using geo-statistical modeling by ordinary least squares (OLS) and geographically weighted regression (GWR) procedures, was also made. The results represented that the GWR model with higher S2, lower residuals and lower RMSE is an optimized geo-statistical model for rainfall modeling of this area. This model can explain spatio-temporal rainfall distribution in northwest of Iran in a diversified topographical and geographical background. This model revealed that two spatial factors including elevation and slope, have the most important role in the summer rainfall behavior.Therefore Elevations in the mountainous and eastern parts of Lake Urmia, Latitude in the northern regions and slopes in the east of the region, have the most role in the spatial variations of summer precipitation in northwestern Iran.
Dr Younes Khosravi, Mehdi Dostkamian, Allah Morad Taherian, Amin Shiri Karim Vand,
Volume 18, Issue 50 (3-2018)
Abstract
Survey of advection of cold waves in Iran is the main aim of this study. In this regard, 45 synoptic stations were employed and studied. In order to investigate the thermal advection of cold waves, 1000, 850, 700 and 500 hp levels were reviewed and analyzed. Results indicated that cold waves in Iran most affected thermal advection caused by Tibet- Siberia, Siberias integrated Turkmenistan high-pressure, High pressure belt of Siberia - East Europe High pressure, Siberian high-pressure multi-core pattern and High-pressure belt of East of Caspian Sea integrated Black Sea High pressure. In the meantime, thermal advection of Siberian high pressure has been more impressive than other patterns. This system moved towards lower latitudes by anti-cyclone moving, So the cold weather of northern latitudes loss in lower latitudes North East of Iran, North West and Central parts of Iran. However, when Siberian high pressure combined with other patterns, its role in the advection of cold air have been considerable
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
Ali Ahmadabadi, Zahra Sedighifar,
Volume 18, Issue 51 (6-2018)
Abstract
Climate change is one of the most important challenges that has affected various parts of human life on Earth. In the present study, in order to investigate the climate change, three synoptic stations of Karaj, Mehrabad and Dashan Tepeh with the help of the statistical statistic downscaling model (SDSM) model were used to predict the statistical period of 2016-2045. Finally, the effects of climate change on the hydrologic conditions of the basin with the help of the model (SWAT) was simulated by the Soil and Water Assessment Tool. The amount of surface runoff and runoff at the study area is 10.59 mm in the studied observation period, but this rate was estimated to be 21.27 mm for the predicted period due to the increase of urbanization and changes in utilization. The results of the research, while highlighting the importance of the effects of climate change, are necessary for their application in applying proper management to adapt to climate change in the future policies of the basin management.
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.
Mohamad Hadi Setavand, Fazel Hajizadeh, Hosin Yaghfoori,
Volume 19, Issue 52 (3-2019)
Abstract
Urban Public Service structuring the form and nature of the physical, social and spatial city; Therefore injustice in how to distribute it, the structure, on nature of the city and class segregation affects urban areas and Urban management is faced with serious challenges. In the same vein, the main purpose of this study, Spatial analysis of enjoyment levels ten main areas of the Shiraz city of Urban service. The research method is descriptive-analytical and its type is practical. In collecting data library method and field has been used. The statistical population of ten main areas of the Shiraz city that according to the 10 overall index and 49 components crucial public services Assessed. For analysis and grading the urban districts from the view point of enjoing public services, some models including Fuzzy TOPSIS, VIKOR and WASPAS have been used and for reaching to a unified result in data analysis of different models, the blended average of ranks has been used. The results of this method showed that Areas 1, 2 and 4 have in the first rank, areas 3, 6 and 7 in the category semi, Districts 8 and 10 low Enjoyment and Zones 5 and 9 enjoyment been lacking in class. The findings of this study show that the distribution of public services in areas of City Shiraz with Spatial justice approach does not match .At the end of this article, strategies according to research findings been proposed.
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Volume 19, Issue 52 (3-2019)
Abstract
The heat waves today are one of the most important climatic hazards in the world. According to many scientists, the Severe and frequent occurrence of heat waves in recent years has been due to the emission of greenhouse gases and consequent increased global warming. The purpose of this study is to investigate changes in the frequency and intensity of heat waves As well as their relationship with Global land-ocean temperature anomalies and greenhouse gases in the north-west of Iran. At First, maximum temperature of two meters of the surface during the period from 1851 to 2014 for 164 years was obtained from NASA’s website, then the maps of heat waves was drawn and extracted. Then, we analyzed and evaluated the frequency and severity of the heat waves, as well as changes in the annual, decade, fifty years old fluctuations and their centenary were analyzed. To achieve the research objectives, Pearson and Spearman correlation methods, linear and polynomial regression and non-parametric Mann-Kendall test were used. The results showed that the frequency of occurrence of heat waves in the considered period interval is incremental and relevant, and the most frequency of occurrence was in decades. Also the intensity of the heat waves is associated with a relatively significant increase, and the most intense heat waves occurred in the decades of the late 20th and early 21st century until the present period. The results of the correlation coefficients indicated that the intensity and frequency of the heat wave incidence have a positive and significant correlation with the Global land-ocean temperature anomalies. The results of investigating the relationship between frequency and intensity of heat waves with 4 important greenhouse gases, including: (CO2, CH4, N2O, SF6), showed that, except for the positive and significant correlation of carbon dioxide gas with the most severe heat waves in June, There was no meaningful relationship between them. The results of the Mann-Kendall test indicate an incremental and significant increase in the frequency and intensity of heat wave events in the North-West region of Iran.
Shadieh Heydari Tasheh Kaboud, Younes Khoshkhoo,
Volume 19, Issue 53 (6-2019)
Abstract
The aim of this research is the study of the climate change impacts on the seasonal and annual reference evapotranspiration time scales in some selected stations located in the West of Iran. To this purpose, four stations including Sanandaj, Saghez, Khorramabad and Kermanshah synoptic stations with enough long-term data were selected and the climate change impact on the reference evapotranspiration of these stations under two RCP2.6 and RCP8.5 scenarios in three future time periods including 2011-2040, 2041-2070 and 2071-2100 in comparison with the 1970-1999 base period was studied. The FAO-Penman-Montieth method was applied to calculating reference evapotranspiration and the CanESM2 general circulation model and SDSM downscaling method were used to simulating future climate conditions under the climatic scenarios. The results showed that the mean reference evapotranspiration in the annual and autumn and winter time scales in comparison to the base period will significantly increase for all of the studied stations under all of the scenarios and periods at the 0.01 confidence level. For spring season, the only significant change of the future period mean reference evapotranspiration compared to the base period in the all of the studied area will be a significant increase at the 0.01 confidence level in the 2071-2100 period under the RCP8.5 scenario and for the summer season, this significant increasing rate will occur in the 2041-2070 and 2071-2100 periods under the RCP8.5 scenario. The overall results of this research showed that the highest increasing rate of the future periods in comparison with the base period for all of the seasonal and annual time periods and for all of the studied area will under RCP8.5 scenario and in the 2071-2100 time periods. by comparing the reference evapotranspiration change rates between the different seasonal and annual scales, the results showed that the increasing rate of the mean reference evapotranspiration at the West of Iran will be very remarkably in the autumn and winter seasons compared to the other time scales.
