In this study, used the data of the Modis satellite. Satellite in the province of Hamadan for a period of 15 years to study and monitor the status of the leaf area index. The leaf area index data were analyzed. After extraction from the Modus website, coding was done in software and then extracted from the maps. Finally, the annual time series of leaf area index was obtained and its relation with rainfall and average temperature during these years. In order to investigate better, the cells above the one representing a better condition and higher leaf area density. In this regard, the years 2002, 2008 and 2011 were (0.01, 0.03, and 0.03%) of the lowest pixels higher than 1 and 2016 with 0.24 and 2014, 2009 and 2010 with 0.07 pixels higher than 1, the highest number of pixels. The common aspect of all years shows that in terms of pixels above the common places, all the years: the southern Hamadan gardens in the south of the Moradbeyk Valley, the Nahavand West fields, the south-east Malayer Gardens, the protected area Lashgar in the south-east of Malayer. The only difference seen in different years is the number of pixels. Finally, the time series of the data were the highest in 1389 and the lowest level of leaf area in the years 1381 and 2008.

In this study, we tried to identify the sources of moisture and its direction of heavy rainfall in south and southwest of Iran by using a new algorithm based on atmospheric rivers. For this purpose, daily rainfall of 17 synoptic stations in the period 1986 to 2015 in south and southwestern Iran that have a common time span and fully cover the study area is used.Also from the data set of the National Center for Environmental Prediction / National Center for Atmospheric Research (NCEP / NCAR) European Mid-Term Forecast Center (ECMWF) and ERA-interim data with spatial resolution of 0.75 It was used at 0.75 latitude and longitude with 6 hour resolution. The variables used are integrated water vapor (IWV), specific humidity (q), and orbital and meridional components (u, v). In this research, an algorithm based on the calculation of Vertical Horizontal Vapor Transfer Integral (IVT) is used to identify and navigate atmospheric rivers. The results show that the main source of rainfall moisture is in south and southwestern Iran, south of Red Sea and Gulf of Aden. Of course, the maps show that the Arabian Sea was not affected by the humidity.The Arabian Peninsula also, due to the high moisture transfer rate, as a transitional route, transmits a large amount of moisture to the study area.Finally, the path of moisture to the study area was mapped and identified, and thus considering the three main conditions for the atmospheric river, it can be said that the path obtained is the same as the atmospheric river.

The aim of this study is to identify the spatial distribution of Vertically Integrated Moisture Flux Convergence (Vertically Integrated) Moisture Flux Convergence) on Iran’s atmosphere. To achieve this aim, the monthly ECMWF gridded data used during the period from 1/1979-12/2013. First, based on the specific humidity content in the atmosphere, troposphere divided into three layers (850-1000hPa), mid (700-775hPa) and upper (500-600hPa). In order to achieve VIMFC spatial variations on Iran, spatial self-correlation methods   of globular moron and hot spots used at 90, 95, 99 and 99/99 percent significance levels. The results of this study showed that the spatial distribution of VIMFC in Iran during the first layer of troposphere and especially during warm months of year has a high cluster pattern and in cold months of the year and in the third layer of troposphere cluster pattern decrease. Based on the hot spots index in the first layer of troposphere low height regions, in the second layer of troposphere the  high regions of the Alborz, zagros and central mountains and in the third layer of troposphere alpine regions of central and eastern Iran's mountains has positive spatial self-correlation (hot spots). The results show that in winter and autumn during the second period (1999-2013), the range of hot spots of the VIMFC show a significant reduction compared to the first period (1979-1998) on Iran.

Agriculture, as one of the most important human economic activities, is closely related to the climatic conditions, and any changes in the climatic conditions can have dramatic changes in agriculture. The main objective of this study is to investigate the spatial changes of the Agro Climatic Feasibility Rosa damascena mill Cultivation in Climate change Condition in northern part of Isfahan province including Kashan, Natanz, Ardestan and Aran Bidgol, under the four carbon dioxide emission pathways (RCPs)of 2050.  Two groups of factors involved in agroclimatic feasibility of Rosa damascena mill cultivation including environmental factors (topography, soil) and climatic factors were extracted. Based on these factors, suitable zones of Rosa damascena mill cultivation, were identify using Fuzzy gamma function. In the next step, by simulating the climatic elements of the region in 2050, under the four carbon dioxide emission pathways, the fifth report of the IPCC, replacing the simulated climatic variables of 2050 under the four lines, by re-implementing the fuzzy gamma function, favorable areas of cultivation Rosa damascena mill was identified in each region in each scenario. In the next step, by simulating the climatic elements of the region in 2050, under the four carbon dioxide emission pathways, the fifth report of the IPCC, replacing the simulated climatic variables of 2050 under the four lines, by re-implementing the fuzzy gamma function, favorable areas of cultivation The Rosa damascena mill was identified in each region in each scenario. The results showed that in the base period climate, about 0.33% of the area (9025 km2) has a climate suitable for cultivating Rosa damascena mill and more than 67% of the area of ​​the region has a weak talent. The results of the simulation of the climatic conditions of 2050 under four carbon dioxide emission lines indicate that, under all scenarios, favorable areas for cultivating Rosa damascena mill in the studied area have increased. In the trajectory of 8/8 release, the highest class of agro-colliery was the cultivation of the flowers of Mohammadi gardens

This study aimed to investigate the temporal-spatial and synoptic features of thunderstorms in southwest of Iran (Khuzestan, Chaharmahal & Bakhtiari and Kohkiluyeh & Boyerahmad Provinces) It was compiled using volatility indices during the period 1985-2015. Results of Frequency Analysis of Thunderstorms at Dezful Station with 479 cases the highest frequency and Ramhormes with 252 days had the lowest frequency. In terms of seasonal distribution, spring was the most abundant with 39%. On a monthly basis, April had the lowest frequency with 21% and August with only 2 cases. In terms of thunderstorms the highest frequency of thunderstorms with no thunder was 21 percent. Synoptic analysis: Most of the time there is a nave (at level 500) or low pressure in the west of the region, east of the Mediterranean Sea with its tabs clockwise. From the Red Sea and the Persian Gulf, they entered the south, southwest, and west of Iran On the other hand, the high-pressure system on the Gulf of Aden in the east of the region is round in the clock It has injected moisture, especially at a level of 850 millibars. Interaction between the two systems over the course of the day, It has injected moisture from three sources of the Mediterranean Sea, the Red Sea and then the Persian Gulf into the rising systems of the region. The low-pressure counterclockwise movement of the eastern Mediterranean, Along with the high-altitude clock movement over the Gulf of Aden, it has injected moisture at levels of 850 to 700 degrees.

Information on a variation of impervious surface is useful for understanding urbanization and its impacts on the hydrological cycle, water management, surface energy balances, urban heat island, and biodiversity. This research attempts to detect impervious surfaces and its changes by satellite imagery in Qaemshahr. The relationship between impervious surfaces and changes in land surface temperature in the city was investigated. For this purpose, after obtaining three images in 1978, 2000, and 2017, and performing the necessary preprocessing, the reflection values of the infrared spectrum and ground surface temperature in the study area were calculated. The reflectance of this spectrum was investigated in various land uses vegetation, asphalt and building areas in two parts of the urban and the suburb.  Using the results of ANOVA and Tukey these properties compared to different land uses. By the difference between Permeable surfaces and impervious surfaces, the impervious surface index was calculated. The results of the detection and comparison of the three surveyed images showed that the impervious surfaces in Qaemshahr were significantly increased from 1978 to 2017. In the next step, by calculating the land surface temperature, it was determined that the temperature of the impervious surfaces is higher than the other parts of the study area. An increase in the population of the city followed by an increase in urban construction has led to an increase in impervious surfaces and a reduction in green space and this has caused a rise in city temperatures. The results of this study showed that increasing impervious surfaces has led to an increase of around 4 degrees in the city's temperature. Finally, any increase in the impervious surface at the city will lead to unsustainability in the urban environment, if not accompanied by proper planning.

One of the most important energy sources in the world is solar energy, which is a renewable resource and does not cause any damage to the environment. Which all of these features justify using it as a clean energy source and economically viable cost.. Due to the relatively large area of the Iran in low latitudes and relatively dry climatic conditions, in terms of solar energy utilization it uses excellent conditions. Solar power plants are considered as power generation and transmission networks whose is important that the location features of their construction sites are effective in reducing the risk of investing in solar energy. In this study, using geographic information system and fuzzy valuation method for the criteria and method of weighing (AHP), was considered the potential of the Kavir & desert region and Makran coast for the purpose of obtaining energy from the sun. For this purpose, were used the 14 criteria related to the climatic, infrastructural, and technical and physical conditions of the area. In order to overlap the fuzzy layers were used the usual operators, Gamma, Product and also the Sum Weighted Overlay operator to compare and present the appropriate result. Each of the operators has a different sensitivity to the fuzzy overlap of the layers. For this reason, was considered the Gamma 0.9 operator, due to the high sensitivity for building power plants with high electrical power generation and the Sum Weighted Overlay operator, for the construction of smaller capacity plants. In the overlay map, using the Gamma 0.9 operator, about 2%, and in the overlay map with the weighted operator, about 33% of the study areas were found to be very suitable for the construction of solar power plants.

This study investigates the subtropical anticyclones and summer monsoons of the north hemisphere in the 500 hPa level, effective on Iran in a 38-year period (1975-2012). For this purpose, the data of geopotential heights of 500 hPa at 12 UTC with a spatial resolution of 2 by 2 degrees of the (NCEP/NCAR) were used. Results show that three independent patterns (Azores anticyclone, Saudi anticyclone and North West Africa anticyclone) and four combinatory patterns derived from the independent patterns have controlled the atmosphere of 500 hPa level of Iran. In most cases, the maximum in geopotential heights in above-mentioned anticyclone centers reach to more than 5920 geopotential meters, but often the tongue of these anticyclones control the atmosphere of 500 hPa levels of Iran with the geopotential height of 5880 to 5900 meters. In contrast, at this pressure level, the large-scale monsoon system is very weak and the maximum geopotential height of this system is about 5840 meters. The extent and intensity of the monsoon system has been reduced so that its tongues do not affect the 500 hPa level of Iran at any time. Given that the main factor in the development of large-scale monsoon system is the surface heating (bottom-up formation) and the main factor in the development of subtropical anticyclone is descending of atmospheric dynamics, the main reason for the development of summertime subtropical dynamic anticyclone should be a very strong and unit agent, something other than the summer monsoons.

The purpose of this study is to determine and predict the effects of climate change on architecture using climate models. By clarifying the consequences of the impact of urban architecture on climate change while using the data of surrounding stations with library and field data methods. The climatic parameters of precipitation, temperature and relative humidity of the synoptic station of Miyaneh city during a full period of 32 years (2018-1987) and the possibility of climate change with the models in this city were examined and after obtaining the relevant data Climate change was predicted for the next 84 years through the GCM and SDSM microscale and the AR4 (2007) - HADCM3 (Run 1) - SR-A2 scenarios. In order to evaluate the effects of climate change on the comfort climate of the region, among the bioclimatic models used, the Tarjong model was considered for two periods of 16 and 42 years. In the next 84 years, compared to the last 32 years, the cold months of May, June, July and August will turn into pleasant heat, and in September, the heat will have a great impact on the skin, which indicates a warm climate in the next 84 years. Architectures must be considered.

In this research, coding the rainfalls, prepares daily 45 stations with the statistical period of 20 years to zero and one codes to realize the daily dry periods in west and north west of the country and then, by establishing the main condition of occurrence of code one for 30 stations, we extracted the dry 4 to 10-day frequencies. And the results gained of considering the atmospheric weathering, shows that the most clear rotational pattern in sea level is related to Siberia-Europe high-pressure panels and sometimes both of them that increase the rotation on the region and also, the local high-pressure reinforcement and there is a high altitude in atmospheric middle level which is derived from sample patterns and is placed on the studied region and these sample patterns are from omega, bi-polar and rex models that they are on Russia and Scandinavian countries with some changes. The 500 level TAVA and omega shows well that in most regions, the air course, has decreasing case and so, we can result that placement of a high altitude in atmospheric middle and upper level on the high-pressures of the earth, causes the weather stability and lack of rainfall and as a result, the stability and durability of these conditions for several days, is related to sample patterns.         

The goal of this research is studying the effect of recent climate changes, espeeially heat rise on the amount of effective  rainfall in the lorestan peovince. Effective rainfall is the amount of fall which, after evaporation, is absorbed in the ground. in the ground.in USDA method and the us agriculture, the amount of rain abstorbed in a growth perlod of a plant and available for its consumption is called effective raifoll. The results showed that the amouent of rainfall in the first period is more than that of the second. The frequency of raining days got reduced  in the after-climate- change period. Heat got increased in the second period. Evaporation was more in the second period. Relation humidity got decreased in the second compared to the first period, and wind speed increased by studying the process of the data changes, it became evident that climate change leads to the increased inconsistent rainfalls in the studied climate variables indicate that under the effect of climate change , Based on Vibol method, droughts caused by effective rainfalls were calculated, and the probability of effective rainfalls in 5 time periods was accounted for. It was shown that in the years 1369 to 1396, effective rainfall in the region was scarce, so it was very influential. With Dobif Model, effective rainfall was analyzed, and years with the least effective rainfall for dry farming with positive signal, that is, appropriate conditions, and negative, that is, inappropriate conditions were recorded. Based on linear coefficient, rainfall trends in the three stations of Khorramabad, Aligudarz and Borujerd. Geographical distribution analysis of   effective rainfall showed that in the south and south-east of the province, the coefficient of effective rainfall was more than the rest of the province. This coefficient was decreasing when it comes to the south-west of the province. Effective rainfall decrease was more due to increasing evaporation happening in this part. the effective rainfall in the studied region got decreased, therefore, preserving underground water resources, on which natural life depend, should be considered more than ever.

In this research, we are trying to determine the “beginning time” as well as the “end” of the climatic seasons; and we will focus on identifying the displacement of these dates, which is influenced by the “climate changes” and “descriptionAbstract
The purpose of this study is to investigate possible changes and displacements in Iran's climatic seasons due to climate change. To do this, temperature, relative humidity, water vapor, wind and cloud data for 36 stations were received from the Meteorological Agency over 40 years. The data were divided into two 20-year series to allow comparison. Daily temperature data for each clustering time series were determined, then by considering 7-day sequences, the beginning and end of the seasons. The designated times were tested using the Rayman model. The results of comparing the seasons in the two time series indicated that in all stations, changes in climatic seasons occurred from Insignificant to significant. Climatic seasons in Iran do not correspond to calendar seasons, and climate change, especially temperature changes in recent decades, has caused the seasons to shift and shorten and lengthen. Although the beginning and end of the seasons do not generally correspond to their calendar dates, most of the days of these seasons occur in its calendar periods. The changes that have taken place have not only affected the length of the seasons, and these shifts have also changed the quality of the natural seasons.
Keywords: Climate change, natural seasons, cluster analysis, Rayman model of the qualitative conditions” created in them, compared to the past climatic periods. “Meteorological Organization” data has been used in this research. Forty years of received data, was divided into two groups of 20. Applying SPSS, each group was divided into four stages representing each seasons. From these stages, the beginning time and the end of seasons were determined and the accuracy of the obtained dates was controlled with the comfort indicators of the Rayman model. The results of the comparison of seasons in two time series indicated that, the changes occurred in natural seasons from an almost non-existent one in all stations. Climatic seasons in Iran are not compatible with the summer season and climate change, especially the change in temperature in recent decades, has caused changes and shortening of seasons. Most of the days in these seasons occur during its monthly periods, although the beginning and end of the seasons generally do not match their calendar dates. Changes have not only affected the duration of the season, and these changes have also led to a change in the natural quality of the season.

Change in precipitation features is one of climate change outcome. Change in precipitation amount, especially in warm season, may influences climato-environmental phenomenon as well as human activity. In current research the decadal changes of monthly precipitation over the Caspian coast of Iran territory was evaluated. Accordingly, a large number of rain gauge stations (385 stations), where rainfall is measured painstakingly, have been used. these stations are under the supervision of Meteorological Organization of the country and Ministry of Energy. Since the original dataset pertaining to the precipitation prior to 1966 had noticeable missing values, and the data after 2016 were not accessible, a continuous time period from January 1966 to December 2016 was selected. From the daily precipitation of aforementioned stations contour maps were created using an ordinary Kriging method. The spatial resolution of these precipitation maps was 3 km * 3 km. Our finding showed that during the under investigation period the maximum gradient of precipitation moved from coastal parts toward mountainous area. Decrease in the area with high precipitation and increase in the low precipitation area is an other prominent decadal characteristics. According to the previous study, these changes might attributed to changes in systems which effect precipitation in the Caspian coast of Iran (northward movement in polar vortex, sub-tropical high pressure and cyclone truck). In addition, increasing temperature trends in the summer tend to decrease temperature spatial differences. Therefore, the convectional precipitation during summer has been decreased.

The aim of this study is to synoptic analyze of the number of frost days in a year of Khuzestan province. For this purpose, using the minimum daily temperature data of 12 stations during the statistical period of 1992 to 2017, the Meteorological Organization of the country, 54 days of frost was identified. Sea level pressure, Geopotential Height, Zonal and meridian wind and temperature of 500 hPa data with size of 2/5 * 2/5 degree arc from the National Oceanic and Atmospheric United States of America were extracted. On the matrix of the variance of sea level pressure data in 54 days, the analysis of the basic components was performed and 10 components which identified 83% variance of the sea level pressure. Then, by applying the hierarchical cluster analysis method, the integration method was applied to the scores of the 10 components and 5 patterns of sea level pressure were identified. The results showed that frost phenomenon in Khuzestan province occurs from November to march and its trend is decreasing during the statistical period. Also northern and western parts of the province have allocated the most frequency of frost. Also the synoptic condition analysis of troposphere showed that 5 sea level pressure pattern with different make ups lead to pervasive frosts of Khuzestan province. Weak and moderate frosts formed by the influence of Siberian and European cold high pressure systems. But severe frosts occur with spread of Iceland low pressure to Iran, along with strong cold pressures. Meanwhile, the powerful Siberian high pressure is present in most of the patterns, which its interaction with sub polar and Icelandic low pressure, plays the most role in the most severe frost in the province of Khuzestan. Also in the middle level of troposphere penetration of deep troughs from northern latitudes and east European huge blockings has the most role, which has advection of cold air from the side west of troughs on the country and during the intensity of the frost added to its continuity.
 

Recognition and determination of ecological susceptible regions for proper bedding is importance and vital affair for regional planning and specially agriculture part. Climate and topography are main environmental components which altitude and cultivation product generation capability are depend their in every region.  So , studying of effective climate factors and elements on agriculture have special importance. In current study , in order to agriculture ecological homogeneous geographical regions determination ; satellite images of Geographical Information Bases (GIS) were used which they are provider of new horizon and dimensions for effective discovering and fields resources management and we try to show Rapeseed cultivation ecological zoning usage development by combining modern tools , instruments and methods at Ardebil plain region. In order to recognition of mentioned susceptible regions in studied case climate data statistics were used that they include ; temperature degree , precipitation, relative humidity and environmental capability data such as ; inclination, height and multi-criteria decision making based on Analysis of Networks Process(ANP). Then layers were prepared by weighting and according to criteria and they were combined and also layers overlapping were done on GIS environment and ultimate layer of fields proportion was prepared for Rapeseed cultivation. Based on results analysis , studied region fields for Rapeseed cultivation include 33/38% without limitation ; 02/10% of fields with low limitation; 96/33% with medium limitation ; 71/17% of fields with high limitation

Atmospheric circulation is important to determine the surface climate and environment, and affect regional climate and surface features. In this study, to quantify its effect, the classification system, developed by Lamb is applied to obtain circulation information for Ardabil, North West Province in Iran, on a daily basis, and is a method to classify synoptic weather for study area. For that purpose, daily mean sea-level pressure (MSLP) for extreme precipitation days from 1971 to 2007 is used to derive six circulation indices and to provide a circulation catalogue with 27 circulation types. The frequency of circulation types over different periods is computed and described. Five circulation types are most recognised in this study: E, SE, A, C and CSE. The catalogue and the associated indices provide a tool to interpret the regional climate and precipitation, and deal with the linkage between the mean extreme regional precipitations in north western of Iran and the large-scale circulation. Five circulation types E, A, SE, C and CSE are associated with high precipitation and rainy seasons (spring and September) but the most precipitation rate is resulted of cyclone family. Low pressure of north latitudes and central area of Iran with low pressure of gang from Pakistan and India.  SE is almost dominant circulation type over the years. The cold season started from august to march is characterized by frequent directional flows, especially E, SE, A, C and CSE whereas in  warm period (Apr–Aug) SE, NE, AE have  smaller role, especially in July, August and September more frequent flows dominated by SE and E. 

 The study of meteorological characteristics and its variability is important in assessing the climate change impacts for water resources management. Trend analysis of hydrological and meteorological time series is a method for determining the change in climate variables that is performed with different parametric and non-parametric methods. In this research, the annual, seasonal and monthly trends were analyzed regarding rainfall and temperature time series for 1986-2017 in 28 stations of Kashafroud basin in the Northeast of Iran. For this purpose, the annual, seasonal and monthly trends were evaluated using non-parametric Mann Kendall and Pettitt test at 95% level significance. The results showed the trend for the monthly maximum temperature in spring and winter and also the annual trend for all stations was increasing, whereas the summer and autumn pattern differed. The trend of minimum temperature in all seasons and stations do not have a uniform pattern. The results of precipitation trend indicated that the annual precipitation of the basin had not changed and did not have a significant trend in 5% level of significance. Precipitation of the basin in the winter decreased. There was an increasing trend in the Southern half of the basin in autumn. The noticeable decrease of precipitation in winter season especially during January and February with an increase in November can be a serious challenge for water resource management of basin during the dry season.