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Estimating the Growing Degree Days in the Northwest of Iran based on Climate Change Models
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.
 


The effect of climate change on the precipitable water content in the north coast of the Persian Gulf
Tayebeh Dehghani, Mohammad Saligheh, Bohloul Alijani,
Volume 18, Issue 49 (3-2018)
Abstract
In order to detect climate change, a variety of climate indicators can be used which is often considered temperature and precipitation. In order to investigate the effect of climate change on the amount of precipitation in the north coast of the Persian Gulf, it simulated the precipitable water for 2017-2050 based on the RCP4.5 model of the Hadcm3 model. The NCEP / NCAR base-station data with an arc-value of 0.125 was used to analyze the past and present precipitable water patterns and to reveal the process of this time series. Time series analysis of precipitable water was performed using two SENS tilt estimators and Man-Kendall test. The results indicated that the annual time series of rain water was increasing in the region, every year, 0.05 mm, the precipitated water increased and it tended to become more homogeneous, this increase in the significance level of 0.95. The precipitation rate in the eastern part of the region was higher than other areas. Before 1989, several fluctuations were observed in the rainy season of precipitable water, but none was statistically significant at the confidence level of 95%, but since 1989, the trend has increased significantly at a confidence level of 0.95. This spatial behavior of precipitable water can actually have occurred in response to the increase in the overall temperature of the area and can be considered as a profile of climate change in the region.
 

Optimal slope and azimuth analysis for photovoltaic panels based on solar radiation in Kashan
Ali Reza Rahimi, Ali Reza Karbalaee Doree, Mohammad Reza Karbalaee,
Volume 18, Issue 49 (3-2018)
Abstract
One of the most important parameters in maximal use of radiant energy is the proper deployment of photovoltaic. The purpose of this study was to determine the optimum setting and tilt for installing photovoltaic panel in Kashan city. For this purpose, using the Masters Gilbert physical relations and relationships, the radiation received on the surface of the panel is calculated. The results of this study indicate that the amount of radiation received on the collector's surface in the south and in different slopes, 64 percent of the time of year, is more than the radiation on the panel surface mounted in the direction of the southeast or west with different slope angles. The highest amount of radiation is in the Azimuth to the south at a gradient of 30 degrees and 40 degrees; Southwest Azimuth (30 degrees) is almost similar to the South Azimuth and only in the southeast west, in summer, glides near the verge, they receive more radiation than the south. The amount of radiation received on the surface of the panel in the direction of south east west (Azimuth 60 °) on different slopes in 87% of the year is greater than the radiation on the panel surface mounted east or west (90 ° azimuth) with different slope angles. By comparing the results, it turns out that the direction of the photovoltaic panel installation will change, as the south changes to the east or west, the intensity of radiation will decrease in the days of the year. The highest photovoltaic energy output in Kashan is in the direction to the south, and with the angle of installation of photovoltaic panel 30 degrees from the horizon line. The most suitable slope for mounting panels between 30 and 40 degrees was obtained from other slopes.

Synoptic analysis and satellite monitoring dust phenomenon in Kermanshah province in 1987-2010 (case study: wide spread dust in 17 and 18 June 2009)
Professor Kamal Omidvar, Miss Nesa Sepandar,
Volume 18, Issue 49 (3-2018)
Abstract
In this study, the dust situation in 6 synoptic stations of Kermanshah province was investigated in the period 1987-1992. To study this phenomenon, dust days were extracted in 2009 with code (06) from the current air index. Then data from different bar levels were taken from the National Oceanic and Atmospheric Organization (NCEP / NCAR) database and maps were plotted in the Grads software. Finally, through the processing of MODIS satellite imagery, with the application of the brightness temperature index, round detection and the dust was made and its territory expanded. The results of the study showed that at low ground level, when the European high-pressure system retreated to the north and west, Sudan's low pressure existed in the eastern Mediterranean, and the system moved southwest to the northeast, and when they entered, the disturbance zone is caused due to the lack of moisture in the dust, the main sources of dust in the province of Kermanshah include the deserts of northern Arabia, southern Iraq, and somewhat north of the sub-Saharan Africa.

Precipitation Trends Analysis in Southwest Asia during the Last Half Century
Sayyed Mohammad Hosseini,
Volume 18, Issue 49 (3-2018)
Abstract
Precipitation is a climatic elements that have temporal - spatial distribution. In this research database of Global Precipitation Climatology Centre (GPCC) with a resolution 0.5×0.5 degree for 50 year is used, that was constituted with dimensions of 12800*600. Temporal data are on the columns and pixels (spatial data) located on the rows. The results show an increasing trend in spring and fall but in summer and winter precipitation trend has been decreased. The most amount of precipitation is located in the northern parts of the Black Sea and Mediterranean Sea, Southeast Asia, southern coast of the Caspian and Central Zagros Mountains. Most of Middle East (about %95) have not trend and only in some parts of Kazakhstan, Afghanistan, Pakistan ,central Iran, and areas in lower-latitude have positive trend and some East and northwest parts of Iran and some parts of Middle East also have decreasing trend of precipitation. The highest percent of area of precipitation trend gradient is 0 to 0.5.
 

Determine the probability distribution function of frosts in Iran during the period (1981-2010)
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

Changes in Moisture entering the atmosphere of Iran and its relationship with seasonal wet and dry periods
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.

Investigation and analysis of cycles and spatial correlation model of Iranian monthly rainfalls
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.

Analysis of heating degree day requirments changes under climate change in South Khorasan
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.

The Temporal Analysis of Dust Storms in Khoramabad Synoptic Station
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.

Forecasting Average Daily Temperature in the Khorasan Razavi Province
Sayyed Mohamad Hosseini, Abdolhossein Adelzadeh,
Volume 19, Issue 52 (3-2019)
Abstract

In this research, applied synoptic model for determining the average daily temperature and its relationship with the Geopotential Height in middle level (500 HPa). Therefore, two database were used: database of atmospheric circulations, includes the data of geopotential height at 500 HPa and its data were extracted from the NCEP/DOE(US National Oceanic and Atmospheric Administration) in hours 00:00; 03:00; 06:00; 09:00; 12:00; 15:00; 18:00; and 21:00 in Zulu and other, database of environmental (surface) events. Contain of average daily temperature in the Mashhad, Torbat-Heydarieh and Sabzevar stations in Khorasan Razavi Province. The maximum and minimum of these stations in the time interval from 01/01/1987 to 01/01/2014 equal as 9862 days from the meteorological organization of Iran. Then, was calculated the correlation of the average daily temperature of selected stations with high atmospheric data (500 HPa level) with the northern hemisphere in Surfer Software. The result shown, four regions in the northern hemisphere which had high correlations with selected stations. The correlation results suggest that the United States has 25 pixels, Northern China 25 pixels, Africa 45 pixels and Japan with 65 pixels. Then, weighted average of pixels in heights by multiple regression equation station. The results of diagnostic models indicate that, per geopotential height increase in the profile, the average daily temperatures of selected stations in the Sabzevar 1.4, Torbat-Heydarieh 1.3 and Mashhad 1.3 degrees Celsius will increase.
 


Predicting of Temporal-Spatial Sand Dunes Transition Caused by Marine Storms (Case Study: The Coast of Makran, Iran)
Mr Soleiman Pirouzzadeh, Mahmood Khosravi, Samad Fotohi,
Volume 19, Issue 52 (3-2019)
Abstract
 Studies show that 14 provinces are impacted by wind erosion and the movement of sand dunes. The sand originated from the shores of Oman Sea is the most important environmental hazards that threaten the already large number of rural settlements. Sands of marine origin are available on the beach and away from the sea of dunes in addition of marine origin, Predictive models for planning sustainable use of land use and land cover in a country like Iran that land use is changing rapidly, there is an urgent need; To detect and predict changes in land cover changes overview to better manage natural resources and protect marginal lands beaches and is very effective long-term policy measures. The aim of this paper is  modeling and prediction of changes in  land-use in 2035 by using  CA Markov model and Landsat satellite images in the West of Zarabad,( The coasts of Makran). Then to determine the changes in the movement of sand dunes in the study area ranged from twenty-three years (1991-2014), satellite imageries from Landsat 7 and 8(ETM+ sensor) with 15 and 30 meters spatial resolution , was used. The 1991, 2001and 2014 month August images were used, this images from website of the US Geological Survey (USGS) have been prepared. Finally, these images by using Geographic Information System (GIS), ENVI and IDRISI softwares were analyzed. The results  showed that the changes in the region the largest increase in the interest of sand dunes in the year 1991 (25.561) km², in 2001 (10 . 568) km², and in 2014 (45.578), and the increase of (17.198) km², has experienced. The results also estimated that in future (2035) sand dunes area increase to 592.45 km².This  increase in area of sand dunes occur in the absence of proper and efficient management is done in order to stabilize the sand. This increase resulted from changed moorland 162 km²of land area (27%) and 12 kilometers of vegetation (2%) and 23 km² of fluvial (3.4%). These changes makes heavily exposed about 6 villages (Karti,Gnjk, Sohroki, Pyvshk, Vanak and Kalirak) to the movement of running sands.

Analysis of heat waves temporal fluctuation in North - West region of Iran and their relationship with greenhouse gases and global land-ocean temperature anomalies
, , ,
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.

Zoning atmospheric Hazards in North West of Iran
Dr Batool Zeinali, Sima Khalili, Saideh Eiyni,
Volume 19, Issue 53 (6-2019)
Abstract
The aim of current research is atmospheric hazards climate zoning in Iran Northwest. So meteorological organization data were used in cases such as mean temperature , minimum temperature , maximum temperature, precipitation in monthly and daily scale for 13 synoptic stations in range of East Azerbaijan province, West Azerbaijan province) and Ardebil province during 26 years. (1990-2015) in this research , it was investigated 10 main atmospheric hazards such as famine or drought , hailstone,, heavy snow , thunder storm, severe precipitation, margin precipitation , blizzard , fogging , dust storm in range of Northwest bound. Then happening frequency maps were prepared with separating form for hazards by using Geographic information system. (GIS) Also spatial zoning maps were prepared for every class. Finally by combining all of hazards investigation; it was prepared Northwest region atmospheric hazards extensive map. Results show that, East, Southeast, center and West parts in Northwest region are located among most hazard zones based on happening frequency. But Northeast parts and zones have the least hazards. Also results express that blizzard and dust storm are main atmospheric hazards at Northwest regionThe highest hazard frequency in Northwest region relate to blizzard with 4148 hazards during 1990-2015 study period. The highest blizzard frequency in Ahar station is observed with 514 hazards. The second hazard in Northwest relate to dust phenomenon with 1948 cases. The highest frequency of mentioned case was observed in Maragheh station with 410 hazards. The third case in Northwest relate to thunder storm phenomenon with 1773 hazards. The sixth case relate to icing phenomenon with 1315 hazards meaning. The highest icing frequency is observed in Khalkhal station with 144 hazards. The seventh case relate to hailstone phenomenon at Northwest with 341 hazards. The highest of hailstone frequency is observed in Maragheh station with 56 hazards. The eighth case relate to fogging phenomenon with 333 hazards. The highest of fogging is observe in Ahar station with 135 hazards. The ninth case relate to famine or drought phenomenon at Northwest with 168 hazards. The highest of famine or drought frequency is observed in Urmia and Ardebil stations with 16 hazards totally. The highest margin precipitation is observed in Parsabad station with 19 hazards. The lowest frequency of margin precipitation relate to Makou and Khalkhal stations with 4 hazards totally.

Projection and prediction of the annual and seasonal future reference evapotranspiration time scales in the West of Iran under RCP emission scenarios
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.

Radiation balance and urban land use (case study: Kermanshah city)
Taher Safarrad, Mehran Mansourinia, Hersh Entezami,
Volume 19, Issue 53 (6-2019)
Abstract
Population growth and urbanization development are the main triggering factors of changes in urban land uses. These, in turn, result in changes in the components of radiation balance. The present study tries to analyze the role of urban land uses in radiation balance by calculating net radiation and its analysis. For this purpose, the Landsat 8 satellite image of 2016 was used. Characteristics of radiation flux including net radiation flux (RN), ground surface albedo (α), incoming longwave radiation (RL↓), incoming shortwave radiation (RS↓), outgoing longwave radiation (RL↑), and ground surface temperature were computed using Sebal algorithm.The values ​​of these components in different land uses (compressed residential, scattered residential, green area and wastelands) were analyzed using one-way analysis of variance (ANOVA) and Tukey’s test. The results of this study showed that the selected land uses have significant differences in the amount of radiation flux, therefore the wastelands are warmer than the residential areas by about 6 oC and the residential areas are warmer than the green areas by about 1.5 oC. The results also indicated that these differences are due to changes in output energy (α and RL↑), and any change in land use over time will ultimately lead to a change in the radiation balance and the temperature of those places, which this temperature increase, is different from the increase of the temperature due to global warming.

Flood risk zoning due to climate change under RCP 8.5 scenario using hydrologic model SWAT in Gis (Azarshahr basin)
Mohammadreza Goodarzi, Atiyeh Fatehifar,
Volume 19, Issue 53 (6-2019)
Abstract
In the present time, with the increase of industrial activities and the neglected environmental issues, the effects of climate change have become more evident and poses this phenomenon as a global difficult. Increasing the probability of occurrence of extreme climatic events such as flood and increasing the frequency and intensity of the effects of climate change. The northwest of the country is one of the most vulnerable areas of the country due to its semi-arid and mountainous climates and high rainfall variability. Therefore, zoning due to climate change is essential. Therefore, in this study, in order to investigate the risk of flood in the Azarshahr basin, due to climate change, using the CanESM2 general circulation model under RCP8.5 scenarios negativity according to the assessment report fifth IPCC, rainfall and temperature variables were down scaling by Statistical down scaling model (SDSM). Then,with hydrological model SWAT the daily runoff, the basin map and the lines of the canals are achieved. The results of the evaluation of the SDSM model with a coefficient of determination and Nash-Sutcliff 0.95 on average represent the good performance of the model in the down scaling of large scale data. The results show an increase of 0.23 ° C and 4.53% rainfall and maximum discharge. The basin is zoned with the combination of the maximum mean discharge map, the coefficient and distance from the river with the AHP approach. Due to the zoning they are 41.55% of the area of the basin, at very low and low risk, 27.23% at average risk and 31.2% at high and very high risk. Also, with the final map, it became clear that the mid-basin had a high risk due to its prerequisite conditions and that it needed to carry out managerial actions.

Statistical analyzes and anomalies of precipitation in cold period in order to understand the effect of climate change on different regions of Iran (1951-2010)
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.

Analysis of Drought Spatial Statistics in Iran
Saeed Javizadeh, Zahra Hejazizadeh,
Volume 19, Issue 53 (6-2019)
Abstract
Drought is one of the environmental events and an inseparable part of climatic fluctuations. This phenomenon is one of the main characteristics of the various climates. Awareness of spatiotemporal behavior is effective in land planning. The spatial statistical methods provide the means by which they analyze the spatial patterns of random variables such as precipitation. In this study, using the rainfall data of 84 selected synoptic stations during the period of 30 years (1985 to 2014) in Iran, the spatial analysis of drought has been investigated. Initially, using SPI values (timescales 3, 6, 12, 24 and 48 months), drought and traumatic periods of the area were identified and using the Geostatistic Analyst extension, the drought was zoned by interpolation methods. Moran statistics were used to explain the pattern of drought in Iran. The results of Moran index for drought showed that the values for different years during the statistical period have a positive and close to one, indicating that the SPI drought index data has spatial self-correlation and cluster pattern. Also, the results of Z score and P-value values, clustering of a spatial distribution of drought, were confirmed.

Synoptic Analysis of Early Heat Waves in Northwest of Iran
Dr Mahmoud Hooshyar, Dr Behrouz Sobhani, Nader Parvin,
Volume 19, Issue 54 (9-2019)
Abstract
Early heat waves are extreme events that cause heavy losses in plant and animal life and cause many social and economic problems for communities. The purpose of this study was to identify synoptic patterns and statistical analysis of preterm heat waves in northwestern Iran. To do this, the maximum daily temperature data of March 14th was used for fourteen synoptic stations in the northwest of the country during the statistical period (1333-1393) Hijri Shamsi. Then, on the basis of the threshold, the Baldy index was selected for 61 days of heat wave. All statistical characteristics of the data were processed in SPSS software. They were The elevation data of the middle atmosphere of the atmosphere was extracted from a NCEP / NCAR database on a network with an arc 2/5 × 2/5 degree on the 0 to 70 degree eastern longitude and 0 to 60 degrees north latitude. The matrix was made up of 864 columns in 40 rows, with rows of days with thermal waves and elevation data on the columns on the middle of the atmosphere. The analysis of the basic components was performed on the algebraic data matrix matrix And 12 components that account for about 93 of the variations in pressure levels above 500 hp, were identified. To identify the coherent patterns, cluster analysis was performed on the scores of the components by the WARD integration method. Five types of pre-heat generation waveform patterns were identified. The results of this study showed that the premature heat waves in the northwest of Iran are due to high altitude formation in southern Arabia, the Aden valley and the center of Sudan at a level of 500 hpa and the formation of Sudan's low pressure in the sea level and the discharge of its tabs to the north and northeast of the region The case study (Northwest of Iran) also includes events occurring.
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