Climatology
Saeed jahanbakhsh; Majid Rezaei Banafsheh; Alimohammad Khorshiddoust; Hajar Farahmand
Abstract
In recent years, South-east and east of Iran has become one of the most important hotspots of dust events due to numerous droughts, upstream dams and severe land use changes. In order to evaluate the seasonal variations of dust, 15 synoptic stations were selected during 1980–2015 and then extracted ...
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In recent years, South-east and east of Iran has become one of the most important hotspots of dust events due to numerous droughts, upstream dams and severe land use changes. In order to evaluate the seasonal variations of dust, 15 synoptic stations were selected during 1980–2015 and then extracted from the present weather codes. Additionally, the AOD index of the Terra MODIS satellite sensor and the Aura Satellite Aerial Index of Absorption (AAI) were used during the period 2015–2005. Mann-Kendall nonparametric test was used to investigate the trend of dust days and Spearman correlation method was used for correlation of dust days. The average days of dust in this region are 9 days and maximum days of dusty days are 45 days that occur in Zabol station at summer. Intra-seasonal variations of dust over east and southwestern of Iran have two maximum phases at spring and summer. Dust also has an inverse relationship with altitude and latitude. Climate parameters, drying up of rivers and lakes, and land use changes are three major factors in dust production in eastern and southeastern Iran. Main sources of dust production and emission over the region are (1) Makran coast; (2) Hamoun and Jazmourian dried bed (3) Lut Plain and (4) Border region of Iran, Afghanistan and Pakistan. At most stations except Zabul, Bam and Kerman have an increasing trend of dust events.
Yousef Zarei; Ali Mohammad Khorshiddoust; Majid Rezaeebanafshe; Hashem Rostamzadeh
Abstract
Climate change is one of the main problems on Earth today, so predicting these changes in the future and their impacts on water resources, the natural environment, agriculture, and environmental, economic and social impacts is of particular importance. Therefore, in the present study, the effects of ...
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Climate change is one of the main problems on Earth today, so predicting these changes in the future and their impacts on water resources, the natural environment, agriculture, and environmental, economic and social impacts is of particular importance. Therefore, in the present study, the effects of global climate change on different climatic regions of the country were studied in 12 climatic regions. In this study, NCEP data and climatic elements of precipitation, maximum and minimum temperature were used for statistical downscaling with SDSM model. And using the CanEMS2 model output under RCP scenarios for the three statistical periods of 2011-2040, 2041-2070, and 2071-2099 annual climate change data were obtained. Correlation coefficient, determination coefficient and error indexes of RMSE, MSE and MAD were used to evaluate the performance of the model. However, the results showed that the accuracy of the model was different at different stations. In this way, each model performs better than rainfall in simulating minimum and maximum temperatures. The annual long-run results also show that precipitation will decrease in all climates studied in the coming decades, with the largest decrease occurring in semi-warm (35%) and very humid and temperate (32%) desert areas. But minimum and maximum temperature variations will be different in different climatic regions so that under RCP scenarios during all statistical periods at Sabzevar and Tabas stations minimum temperature changes will decrease but in other climatic regions the trend of minimum and maximum temperatures will be incremental. The highest minimum and maximum temperature increases based on RCP scenarios under RCP8.5 scenario during the period 2071-2099 in the cold mountain climatic region will be 3.03, 4.27 ° C, respectively.
Climatology
Monir Shirzad; Hajar Feyzi; Majid Rezaei Banafsheh
Abstract
Introduction Reference evaporation and transpiration is one of the important elements of the hydrological cycle, which plays an important role in agricultural studies, water resource management plans, irrigation and drainage network design and water structures (Nuri et al., 2013, Volume twenty, ...
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Introduction Reference evaporation and transpiration is one of the important elements of the hydrological cycle, which plays an important role in agricultural studies, water resource management plans, irrigation and drainage network design and water structures (Nuri et al., 2013, Volume twenty, number five, page 12). Due to the small amount of precipitation and the limitation of water resources in Iran, the correct management of water resources is very important and it is necessary to be careful in using water.Data and MethodIn order to carry out this research, daily climatic data during the years 2014 to 2015 of East Azerbaijan (four stations of Maragheh, Midane, Jolfa and Ahar) were prepared from the regional meteorological organization. After normalization and determination of correlation, the data were used in MATLAB software with artificial neural network method with Lunberg-Marquardt training to 70-30 combination for training and simulation. The input data for the simulation of evaporation and transpiration (temperature, sunshine hours, humidity, wind speed) and the work evaluation criteria are RMSE, R2 and MAE, which we gave priority to the data with less error. Results and DiscussionIn this research, the method based on artificial intelligence (ANN) and three experimental models (Penman Monteith Fau (PMF56), Blaney Kridel (B-C) and Kimberly Penman (K-P) were used to model the non-linear transpiration evaporation system of the reference plant. The results showed that the artificial intelligence method has better accuracy and speed in estimating ET0 compared to experimental methodsConclusionThe results showed that the artificial intelligence method has better accuracy and speed. Also, comparing the method of artificial neural networks with classical methods, the results indicate the appropriateness of the performance of artificial neural networks.
Climatology
Naser Jafarbegloo; Ali Mohammad khorshiddoust; majid rezaei banafsheh; Hashem Rostamzadeh
Abstract
INTRODUCTION
Today, pre-risk awareness has become an integral part of the national development management and planning system in many countries (Civiacumar et al., 2005). Agriculture is inherently sensitive to climatic conditions. The minimum temperature, which has been identified as the most vital ...
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INTRODUCTION
Today, pre-risk awareness has become an integral part of the national development management and planning system in many countries (Civiacumar et al., 2005). Agriculture is inherently sensitive to climatic conditions. The minimum temperature, which has been identified as the most vital determining factor in the distribution of plant species on the planet, can be both a limiting factor and a factor in the spread and species distribution (Rodrigo, 2000: 155). Therefore, in this study, we examined the changes in minimum temperatures in the statistical period (1980-2010) and predicted these changes in the 2050s (2065-2046) in the Northwest of the country using the LARS-WG microscale method and model output. Atmospheric pairings of HadCM3 and MPEH5 were addressed. The prediction of minimum temperature variations to determine the extent of its future changes and considering the necessary measures to minimize the adverse effects of climate change on agricultural products were of great importance. In this regard, general atmospheric circulation models (GCMs) are designed that can simulate climatic parameters.
DATA AND METHODS
In the present study, the output data of two HadCM3 and MPEH5 general circulation models based on two scenarios A2 and B1 were analyzed by LARS-WG statistical method in 21 synoptic stations located in the Northwest of the country. The results were monthly and periodic on the base period (1980-1999) and the 2050s (2046-2065), thereby the minimum temperature was evaluated and analyzed. In assessing the LARS-WG model, the observational and simulation error data were evaluated using MSE, RMSE, MAE and R2, and the model was evaluated for the appropriate region. The results showed that the minimum temperature in the future period will increase compared to the base period in the study area. This increase in air temperature at the study area is based on the HadCM3 and MPEH5 models, on average, 1.9 and 1.7 degrees Celsius to 2065 horizons compared to the base period. The north-eastern part of the northwestern region of Iran will have higher temperatures than the semi-southern regions. In fact, the cooler regions of the high latitudes will face more incremental changes in the amount of minimum temperatures. The results and achievements of this research are important for long-term plans for adaptive measures in the management of fruit gardens, agricultural products and water resources management. In order to calibrate and ensure the accuracy of the LARS-WG microscale model, the model was first implemented for the basic statistical period (1980-2010); then the minimum temperature output and its standard deviation were compared with the observational data of the studied stations, which indicated a small difference between the observed and simulated values and also deviated from their criteria.
RESULTS AND DISCUSSION
The results of evaluation of observational and simulated data by LARS-WG microscale model using RMSE, MSE and MAE error measurement indices for the studied stations indicate that there is a significant difference between the simulated values and the values of the observed observations. There is no critical 0.05 significance levels, and Pearson correlation values between simulated and real data are acceptable at the significance level of 0.01. The obtained results show that the accuracy of the model varies in different stations. In general, the results of error measurement indices indicate that the LARS-WG model is of good accuracy for micro-scaling the parameters under study. In order to better represent and ensure the accuracy of the prediction as well as to investigate the uncertainties in the studied models, the simulated values were compared and observations were made on a long-term average during the base period in the studied stations using comparative graphs. As can be seen, the observed and generated values in the base period at all stations are very close to each other and the LARS-WG model has been successful in simulating the studied parameter. After evaluating the LARS-WG model and ensuring its suitability, the data predicted by the model for two scenarios A2 and B1 using HadCM3 and MPEH5 models and were examined on a monthly and long-term basis. The study of the status of minimum temperature changes of the studied stations in the future period (2065-2056) shows that the minimum temperature is based on both scenarios and in all months and stations compared to the period, the base has increased. Due to the large number of study stations, only stations located in provincial centers of this study are listed.
CONCLUSION
Cold and frost are one of the most significant climatic hazards on fruit trees. This type of climate risk affects different parts every year, especially the cold regions of the northwest of the country. Studies show that in recent years, the rate of economic damage to fruit trees in this region has increased, so in this study, the outlook for changes in minimum temperatures in this region using the LARS-WG statistical microscale model and output two HadCM3 global model and MPEH5 were introduced in the 2050s (2065-2046). For accuracy and precision of the models, error measurement indices and coefficients of determination and correlation were used. The results showed that the LARS-WG model has a good ability to simulate the studied variables in the study area. The results of long-term prediction of the studied models show that the minimum temperature values will increase in all study stations, which is based on HadCM3 and MPEH5 models on average. In the 2050s, and it will be 1.9 and 1.7 respectively, compared to the base period. The results of the studies of Kayo et al. (2016), Sharma et al. (2017), Khalil Aghdam et al. (2012), Qaderzadeh (2015), Sobhani et al. (2015) and Khalili et al. (2015) were confirmed. In general, based on the studied scenarios and models, the minimum temperatures are expected to increase in the study area in the future. By increasing it, the yield of some crops that need cold during the growing and productive period would decrease. It can also reduce snowfall, followed by frost on crops and lack of water in dry seasons. Therefore, due to the fact that following the climate changes, the conditions of the agricultural climatology are also changing, it is necessary for the relevant officials and planners in the agricultural sectors to adopt the necessary strategies to reduce the consequences and adapt to the new climate.
Climatology
Hashem Rostamzadeh; majid rezaei banafsheh; Akbar hosseinnejad
Abstract
Introduction
The global warming of the Earth due greenhouse gases diffusion (GHGs) is undeniable now; over the past century, atmospheric CO2 concentrations have increased significantly and caused an increase in global temperature of 0.44 ° C compared to Pre-industrial era. The Intergovernmental ...
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Introduction
The global warming of the Earth due greenhouse gases diffusion (GHGs) is undeniable now; over the past century, atmospheric CO2 concentrations have increased significantly and caused an increase in global temperature of 0.44 ° C compared to Pre-industrial era. The Intergovernmental Panel on Climate Change’s (IPCC) Fifth Assessment Report (AR5) shows that there is a positive correlation between the amount of CO2 and global temperature rise. Today, climate change has attracted many scientists and researchers. The reason for this is the huge impact this phenomenon has on life on Earth. Potentially, climate change can endanger drinking water supplies, food production, and sustainable development in many parts of the world, For this reason, the International Committee of Climate Change (IPCC) calls for studies on climate change at the regional and local scale. Studies have shown that the mean temperature of the Earth has increased by about 0.18 ± 0.74 °C during the twentieth century And an increase in the temperature of the 21st century is estimated to be 1.8 to 4 degrees centigrade.
materials and methods
In this study, the three-hour temperature data of the synoptic station of Tabriz for the statistical period of 67 years (2017-1951) was prepared. Using Matlab's coding, seasonal and annual time series were prepared for each synoptic. Then, in order to provide the seasonal and annual time SYNOPs for the daily and night temperatures, the data are divided into two groups of nightly temperatures (including mean SYNOPs temperatures from 00:00, 03:00, 18:00 and 21:00) and daily temperature (including average SYNOPs temperatures at 06:00, 09:00, 12:00 and 15:00).
Discussion and results
Temperature is one of the most important elements in climatic zonation and classification, and it plays an important role in the distribution of other climatic elements. Accordingly, fluctuations and temperature changes are very important. In recent decades, the applied results of temperature analysis have led to a study of its long-run fluctuations, especially in the global arena. Therefore, in this study, the temperature fluctuations of three hours (SYNOPs), night temperature and daily temperature of the synoptic station of Tabriz during the statistical period of 1951-2017 and the seasonal and annual time scale were studied.
The results of the study show that SYNOPs, (3:00 pm local time), have more severe changes than other SYNOPs, which in summer increases at 0/66 °C per decade. Most annual changes are related to SYNOP 00:00 (an increase of 0.47 °C). Seasonal variations in daily and nightly temperatures also indicate that the highest changes in the night temperature were observed in summer (an increase of 0/62 °C), and the highest daily temperature changes were observed in spring and summer (an increase of 0.3 °C) Is.
the findings of this study are largely consistent with the findings of other studies in the study area. For example, Dinpajoh et al. (1394) obtained the same results by analyzing the process of weather parameters in Tabriz, indicating an increase in the minimum, maximum and average temperature in Tabriz. The results of the study, Sari Sarraf et al. (1394), also show that in the Urmia Lake basin, the minimum, maximum and average temperature has experienced an increasing trend in the annual and seasonal scale. Jahanbakhsh Asl et al. (1396) also studied the trend of variations in the average monthly cold-year average temperature in the northwest of Iran, with the result that the average minimum temperature in most parts of the northwest is increasing. Therefore, the results of this research and previous studies indicate that the temperature in the study area is increasing. The important thing about this research and its difference with previous studies is the use and application of temperature data. So, using daily temperature data (SYNOPs), the temperature changes were dealt with, while in other studies, the average temperature or minimum and maximum temperature parameters were used, so the results of this study could be information It will provide a more accurate description of the process of temperature variation in the Tabriz Synoptic Station.
Conclusion
According to the results, it can be said that the signs of climate change in Tabriz city, especially in terms of temperature, are visible. Considering the role of temperature in increasing evapotranspiration and urban energy consumption, over the next decade, there should be solutions to better manage water and energy resources, especially heat energy during the warm season.
Climatology
Majid Rezaei Banafsheh; saeid Jahanbakhsh; Shoaieb Abkharabat; Aliakbar Rasouli; Mostafa Karimi
Abstract
Introduction 120-day winds of Sistan are considered as one of the significant phenomenon which has a great impact on the morphology and environment of east and southeast of Iran (Figure.1). The common region for these winds is the border of monsoon region in south of Asia which mainly has sunny and cloudless ...
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Introduction 120-day winds of Sistan are considered as one of the significant phenomenon which has a great impact on the morphology and environment of east and southeast of Iran (Figure.1). The common region for these winds is the border of monsoon region in south of Asia which mainly has sunny and cloudless weather during monsoon period. This condition is due to lack of higher humidity divergence accompanied by tangible decrease of the air on the atmosphere (Salighe, 2010). These winds are the most famous advection system in northern hemisphere whose effects are visible in eastern regions of Iran, west and south of Afghanistan, and northwest of Pakistan(Khosravi, 2008). Data and Methodology In order to evaluate the role of the winds, data network of Geopotential height of 850 hPa (hectopascal) level during a 19-year period (1993-2012) from May to the end of September, the period of 120-day winds of Sistan, were found. These data were of those revisited data of 2.5*2.5 NCEO/NCAR during 2480 days. Then, factor analysis and clustering tests were applied on data network of Geopotential height to classify map patterns (Yarnal, translated by Masoudian, 2006: 100). As a matter of fact 5 clusters were recognized in this study presented in table 1. Dynamic method was used in GrADS software in order to find humidity flux of each region in the quintuplet patterns. Discussion Northern Wind Pattern (120-day wind of Sistan) As a matter of fact 120-day winds of Sistan are a part of northern Trade winds which are the most important source of Caspian Sea high pressure. After passing east of Iran, these winds reach Oman Sea and converge with southern Trade winds. Both of them moved toward Indian Subcontinent and finally enter atmospheric monsoon circulation of south of Asia. High pressure of north of Iran is also a tongue of high pressure Azores which is extended over northern regions of Iran and Caspian Sea by Mediterranean and Black sea Basin. Both existing Gang low during hot period of a year in south of Asia and spreading, its tongues over regions of Middle East make Azores high not be able to penetrate the zone in lower levels of atmosphere (from the earth surface to thelevel 850 hPa.). As a result, Azores high has to locate in northern parts especially north of Iran. Analyzing the curves of geo-potential height, figure (2) precisely shows this phenomenon. Gang low not only is weaken among middle levels of atmospheretongue, but also lost its appearance on Iran Plateau and Arabian Peninsula. Therefore, Azores high tongue also can locate in its normal position and appear with maximum pressure on Iran Plateau and Arabian Peninsula. Figure (3) presents the order of synoptic systems in level 500 hPa. of pattern 1. It shows that Gang low has lost its nature in this level, while Azores high tongue obviously is located on Middle East, especially Iran Plateau and Arabian Peninsula. As a matter of fact atmospheric levels of Geopotential height in pattern 1 (figures 2,3, 4) reveal that as we go away from lower levels of atmosphere to middle levels of atmosphere, Gang low gradually is weaken especially over Iran Plateau and Arabian Peninsula. This situation makes Azores high tongue locate in lower latitude. However, in lower levels (earth surface to level 850 hPa.), as a tongue of Gang comes into some parts of Middle East, expanded tongue of Azores high pressure has to locate on higher latitudes than normal latitudes; on north of Iran Plateau and Caspian Sea.Pattern (2) shows the same order as pattern (1), so it will not be repeated here. In the following, the effect of 120-day winds of Sistan on humidity of the region will be investigated, thus humidity flux is calculated between levels 925-1000 hPa. 850-925 hPa. and 850 -700hPa. Figure (5) shows sum of humidity flux for aforesaid levels of synoptic pattern (1). 120-day winds of Sistan with prevailing north direction in this pattern lead to the formation of a core of humidity flux divergence in east and center of Iran and decrease humidity of the region. As previously mentioned, after passing Iran, Sistan winds reach Oman Sea and north of Indian Ocean, and converge with southern Trade winds. Both of them move toward Indian Subcontinent. In fact, convergence of 120-day Sistan winds (northern Trade winds) and southern Trade winds leads to formation of a strong core of humidity flux convergence on Oman Sea and north of Indian Ocean (figure 5). The sum and average of humidity flux convergence and humidity flux divergence in studied region are presented in table (2). Eastern Wind Pattern The other clusters (3, 4, and 5) have different order from 120-day Sistan winds which are introduced as eastern wind pattern. Unlike clusters (1) and (2), in these clusters (table 1) the wind direction is not northern; in other words, the winds blow with prevailing east direction in east and northeast of Iran, however southeast of Iran experience mild weather at the same time. As synoptic order of pressure system and humidity flux system are mainly the same, pattern (3) will be analyzed precisely. The order of synoptic systems of level 850 hPa. in pattern (3) is presented in figure (5). This map reveals that the contrast between high pressure of north and Gang low differs from northern wind pattern, as on the one hand,the strength and breadth of Gang low increase, while on the other hand the strength and breadth of Azores high tongue (high pressure in north of Iran) decrease. In fact, this condition makes most regions of Iran Plateau in lower levels of atmosphere (1000 hPa, 925 hPa and 850 hPa.) be dominated by Gang low. Besides, this order of synoptic systems eliminates 120-day wind conditions of Sistan and make eastern wind conditions in east and northeast of Iran. Since the orders of synoptic systems of levels 925 hPa. and 1000 hPa are the same as level 850 hPa. they will not be presented here. The orders of synoptic systems in middle levels are different, as in level 700 hPa. Azores high tongue comes to Iran Plateau by Arabian Peninsula (figure 7). This layer of atmosphere is a transition layer from dominance of low pressure pattern in lower layers to high pressure pattern in middle levels and upper atmosphere. Moreover, in level 500 hpa. Azores high tongue dominates Iran Plateau and Arabian Peninsula with more power and breadth. The orders of synoptic systems of clusters 4 and 5 are the same as cluster 3. The sum of humidity flux divergence and humidity flux convergence of pattern 3 are presented in figure (9). In this figure, the core of humidity flux divergence, which covers eastern half and center of Iran, is omitted and a core of humidity flux convergence covers east and southeast of Iran. It can be said that both penetration of Gang low into Iran and lack of 120-day winds provide special conditions in which the zone of humidity flux convergence in north of Indian Ocean moves to southeast of Iran leading to moisture condensation. Conclusion In this study 2 patterns of synoptic systems of warm period in east and southeast of Iran were recognized. First pattern (northern wind pattern) makes 120-day winds of Sistan (cluster 1 and 2). In contrast to Gang low tongue, when high pressure of north of Iran and Caspian Sea are in strong mode, it provides the conditions for 120-day winds of Sistan. On the other hand,in contrast to Gang low tongue increasing its influence and spread over Iran Plateau, when the aforesaid high pressure rollbacks of north of Iran and it is weakened, 120-day winds of Sistan stop and second pattern (eastern wind pattern) starts. In this pattern the winds with prevailing east direction cover east and northeast of Iran (clusters 3, 4,and 5). High pressures of Caspian Sea and north of Iran are a tongue of Azores subtropical high pressure which has to move abnormally to higher latitudes due to coming Gang low into lower atmosphere layer. Since Gang low is an inter-tropical convergence zone moving abnormally to higher latitudes in south of Asia, 120-day winds of Sistan are part of northern Trade winds which are flowing from subtropical high pressure (Azores high tongue in north of Iran) to Gang low in south of Asia (inter-tropical convergence zone). After converging with southern Trade winds on north of Indian Ocean, they move toward Indian Subcontinent. 120-day winds of Sistan exclude the entranceof moisture from Oman Sea and Indian Ocean into southeast of Iran (figure 5). However, as 120-day winds of Sistan stop, a core of humidity flux is formed on southeast of Iran providing the entrance of moisture of water areas into southeast of Iran (figure 9). Generally, weakening of Azores subtropical high will help to provide rainfall conditions in southeast by 2 ways: on the one hand, as Azores high pressure is weakened, the influence of decent factors of this high pressure air in levels 700 hPa. and 500 hPa. decreases. As a result ascent conditions are provided in the zone, but on the other hand the weakening of subtropical high pressure in lower levels of atmosphere (1000 hPa to 850 hPa.) also makes expanded Azores tongue weaken and rollback over north of Iran and Caspian Sea leading to stop 120-day Sistan winds. This phenomenon provides appropriate condition to inject moisture from Oman Sea and Indian Ocean to southeast of Iran.
Climatology
Majid Rezaei Banafsheh; fatemah jafarishandi; Fereshteh Hossien alipour Jazi
Abstract
Introduction In this study, to analyze the effect blocking system on the precipitation during 1379 Sample rain, the weather maps of mean sea level pressure, geopotential height at 500 hpa level, wind components, moisture flux convergence and were analyzed. The data of daily precipitation were analyzed ...
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Introduction In this study, to analyze the effect blocking system on the precipitation during 1379 Sample rain, the weather maps of mean sea level pressure, geopotential height at 500 hpa level, wind components, moisture flux convergence and were analyzed. The data of daily precipitation were analyzed for meteorological stations by using Environmental approachto circulation during 1951 to 2013.The results suggest that three patterns have been effective in a rain storm and the establishment of Scutoff low in the Wast North West Iran and its associated trough displacement and ground accompaniment, which have provided the conditions for the creation of heavy rainfall. Because heavy rainfall is a type of atmospheric anomaly, many researchers are looking at how it occurs in abnormal weather patterns, including blocking patterns and other unusual synoptic patterns. Systems that are cut from the main west turn are called blocking systems (Habibi, 2006: 70). Researchers who have studied blocking systems such as Silman (2008) using the atmospheric-ocean output model, Kumar et al. (2008) using the air forecasting model, Timevios et al. (2010) using the Self Orgnizing Map (SOM), Caspar and Muller (2010) used the clustering method of hierarchy and Hang et al. and Yarahmadi and Marijanji (2011) by studying the low pressure system on the earth's surface, the atmosphere of the mid-atmosphere and the rise of cold weather And Gavidel (2014) have studied blocking system with the occurrence of blocking at 500, 600 and 700 hectopascal levels. Methodology In this study, High-level atmospheric data for rainfall analysis of days that have been rainy for more than 1 day include altitude geopolitical data of 500 HPL (meter potential), Uwind and Vwind (meters per second) and special humidity (grams per kilogram). These data are from 00:00, 06:00, 12:00 and 18:00 Greenwich Mean Time in the range of 0 to 80 degrees north and 0 to 120 degrees east with a spatial resolution of 2.5 × 2.5 degrees. It has been extracted from a database (NCEP / NCAR) affiliated with the United States National Oceanic and Atmospheric Administration. First in the form of an environmental approach to circulation, Rainfall of more than one day in the spring during 62 years of statistics, which is 1379 days, was extracted. From these 1379 rainy days, based on the base index of 99th percentile, precipitation of more than 25.88 mm was selected. Therefore, 58 days of precipitation became the basis for the study of heavy spring rains. Because the purpose of the work is to check the blocking, the period of precipitation should be more than one day to determine the cause of heavy precipitation based on blocking or other systems. Then, using cluster analysis, the clustering of these 58 rainy days was studied. The results showed that three pressure patterns are effective in creating rainfall in Tabriz. For each of the patterns, a representative day with a correlation threshold of 95% was calculated and analyzed. Results and discussion At the time of pressure pattern 1, the Siberian high-pressure range stretched from 45 to 55 degrees north latitude to the west to the northern latitudes of Iran, and with low pressure on Turkey, provided thermal gradient. At the pressure pattern 2, a strong high-pressure nucleus with about 1032 HPL was formed in northern Mongolia. The tabs on this core, along with the high-pressure tabs of Siberia, have created extremely stressful conditions at the site of the low-pressure collision on northwestern Iran and Turkey. At the time of the establishment of the pressure pattern 3, tabs of the high-pressure system of the Scandinavian islands were drawn from the Black Sea to northwestern Iran. On the other hand, the whole of Iran is covered by the low pressure spread by Saudi Arabia. These conditions have led to an increase in the temperature and the provision of fronts and instability in Tabriz. In this way, the heavy rainfall that can be seen in the depths of the heart of this instability can be justified. Conclusion The results of synoptic analysis of pressure patterns related to blocking effective on the occurrence of heavy rainfall in Tabriz area indicate the formation of blocking phenomenon of high pressure type on the region. This system stops the movement of air circulation patterns, during which the patterns governing the atmosphere remain in place for several days. In the face of this system, the waves of the western winds are divided into two branches, north and south. This allows the waves to travel further north or south.
Majeid Rezaei Banafsheh; Kaleil Valizadeh; mina mohsenzadeh
Volume 23, Issue 68 , September 2019, , Pages 111-133
Abstract
Pre-crisis management planning is a matter of paramount importance which nowadays, urban managers have to deal with, especially in the filed of crisis management. In this research, finding locations for multi-purpose crisis management stations in regions 1, 4 and 10 of Tabriz municipality has been studied. ...
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Pre-crisis management planning is a matter of paramount importance which nowadays, urban managers have to deal with, especially in the filed of crisis management. In this research, finding locations for multi-purpose crisis management stations in regions 1, 4 and 10 of Tabriz municipality has been studied. At first step, the parameters affecting the selection of locations have been investigated. After gathering and preparing the layers, raster maps were obtained and subsequently, parameter weighing was done throughout the AHP process using Expertchoice software. At next step, data layers were combined together based on IO Boolean and Fuzzy models and the results were utilized to present some locations as desired onse, Due to the Geographic Information System in solving complex problems of urban and ease of analysis and spatial analysis , the ability of the system to prepare , collate and analyze the layers have been applied . The results obtained from this study, the southern part of the region which was set four as the best urban spaces such as green spaces, educational, sportive and etc, and better access conditions for the establishment of these bases is to have the highest priority and the best places for locating the base of the parks Amir Kabir, Anna, Tawhid and Jihad area around the field to 22 Bahman and a few other points is evaluated
Majid Rezaei Banafsheh; Tahere Jalali Ansaroodi
Volume 22, Issue 64 , September 2018, , Pages 59-79
Abstract
Iran is located in semi-arid region and its annual rainfall average is about one-third of the world's rainfall. In recent decades, in addition to population growth, increasing global temperatures led to wide variations in the earth's surface and has resulted changes to the time and place of precipitation. ...
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Iran is located in semi-arid region and its annual rainfall average is about one-third of the world's rainfall. In recent decades, in addition to population growth, increasing global temperatures led to wide variations in the earth's surface and has resulted changes to the time and place of precipitation. According to close relationship between the hydrological cycle and climate system, any change in climate elements such as precipitation, can have an important impact on the availability of water. The purpose of this research is investigate effects of climate change on spatial and temporal variations of water supply in Tasoj basin by using of HADCM3 model results. In this regard, was used from down scaling data of A2 scenario and then recharge for the period 2030-2013 was predicted by HELP3 hydrological model. The results showed that amount recharge of groundwater in this basin is fluctuating from 12 to 67 mm per year under the A2 scenario. In the future, the western region of the study area will be lower recharge than in other parts of the basin. The reason will be the combined effects of geological and climatic factors. Because of the fine-grained sediments along temperature, evaporation increase and reduced precipitation will be effective in reducing the recharge of this region. Also cross-correlation between precipitation and groundwater recharge showed that southern half of the basin than the northern half will responded in a shorter time period to precipitation changes.
Climatology
Majeid Rezaee Banafshe; Tahare Jalali
Abstract
According to important role of climate parameters such as radiation, temperature, precipitation and the evaporation in water resource management, The purpose of the present investigation, is evaluation of climate change in Tasuj basin and Groundwater level response to these changes in period 2013-2030 ...
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According to important role of climate parameters such as radiation, temperature, precipitation and the evaporation in water resource management, The purpose of the present investigation, is evaluation of climate change in Tasuj basin and Groundwater level response to these changes in period 2013-2030 by scenarios A2, B1, A1B. To do this research, was used the data of Chrchr and Sharafkhaneh evaporation stations and Khoy synoptic station for the period 1985-2012 and water levels data of tasuj basin for the years 2012-2000. Data of temperature, precipitation and sunshine with software LARS-WG and groundwater levels were predicted by artificial neural networks for mentioned period. The results revealed a decrease in precipitation and rise in temperature in each of the three studied scenarios.Maximum decline in water level in A2 scenario and minimum decline in groundwater levels will happen in B1 scenarios. Also study cross-correlation showed the impact of rainfall on groundwater levels is with time lag of 2 months.
Climatology
Majied Rezaee Banafshe; Fateme Jaafari Shendi; Fereshte Hosseinalipour Ghazi; Majied Alimohammadi
Abstract
In this study, frequency and location of Moisture Flux Convergence (MFC) related to heavy rainfall have been analyzed using environmental to circulation approach. Based on the threshold of upper 99 percent, we selected 106 days of the super and overall heavy rainfall from IRIMO data base. MFC’s ...
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In this study, frequency and location of Moisture Flux Convergence (MFC) related to heavy rainfall have been analyzed using environmental to circulation approach. Based on the threshold of upper 99 percent, we selected 106 days of the super and overall heavy rainfall from IRIMO data base. MFC’s frequency and their locations have been detected from 00 to 1200 E and 00 to 800 N in the five levels (1000, 925, 850, 700, 600 and 500 HPa level) at 00:00, 06:00, 12:00 and 18:00 UTC. Analysis of MFC indicated that among upper levels, frequency of MFC in 850 hPa, due to high frequency is very important
Majid Rezaee Banafshe; Hoseyn Hossein Alipour Ghazi; Fatemeh Jaffari Shendi; Majid Alimohammadi
Volume 19, Issue 53 , September 2015, , Pages 117-135
Abstract
In this study, the heavy rainfall of Northwest of Iranhas been analyzed using environmental circulation approach. Isohyte maps were depicted using Kriging method on 14*14 km pixels from 21/3/1961 up to 31/12/2004 (a17508× 533 matrix). Based on these interpolated data we selected super heavy rainfalls ...
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In this study, the heavy rainfall of Northwest of Iranhas been analyzed using environmental circulation approach. Isohyte maps were depicted using Kriging method on 14*14 km pixels from 21/3/1961 up to 31/12/2004 (a17508× 533 matrix). Based on these interpolated data we selected super heavy rainfalls for all in Northwest of Iran as a whole. Heavy rainfall and their locations have been detected from 00 to 1200 E and 00 to 800 N in the five this levels (1000, 925, 850, 700, 600 and 500 hPa level) at 00:00, 06:00, 12:00 and 18:00 UTC. The results of this study showed that four thickness circulation patterns play role in producing these super heavy rainfalls. In analysis of these precipitations one representative day was introduced for every circulation pattern. The analysis showed that the circulation patterns 2 justify the most of precipitations. These findings can play an important role in forecasting the precipitation and preventing from flooding in the region.
Majid Rezayee Banafshe; Fatemeh Sarafroozeh; Tahereh Jalali
Volume 16, Issue 38 , February 2012, , Pages 43-74
Abstract
For investigation of variability of climatic elements of UrmiaLake basin, maximum and minimum daily temperature and daily precipitation data over period of 1984-2006 were analyzed. In this paper, 6 indices for analysis of temperature variability and 8 indices for analysis of precipitation variability ...
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For investigation of variability of climatic elements of UrmiaLake basin, maximum and minimum daily temperature and daily precipitation data over period of 1984-2006 were analyzed. In this paper, 6 indices for analysis of temperature variability and 8 indices for analysis of precipitation variability were used. The trends of these indices were specified using least square approach and for identifying their significance nonparametric, Man-Kendal test was used. Results indicate that over the study period climatic conditions have changed. The number of summer days and warm nights significantly increased with the number of cold days and cold nights reduction. Also total annual precipitation, number of precipitation days (above 2 mm) and number of heavy precipitation days (equal or above 10 mm) have significant reduction. Moreover, in the study period the number of consecutive wet days has significant reduction, but increasing of consecutive dry days is not significant.
Masood Goodarzi; Saeed Jahanbakhsh Asl; Majid Rezaee Banafsheh
Volume 16, Issue 37 , November 2011, , Pages 133-149
Abstract
Flood risk estimation is one of the most important subjects for hydrologists and other scientists. The main objective of flood risk estimation is to study the past events in order to foresee the future flood risk. There are various methods for flood risk estimation. Rainfall- runoff and empirical equations ...
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Flood risk estimation is one of the most important subjects for hydrologists and other scientists. The main objective of flood risk estimation is to study the past events in order to foresee the future flood risk. There are various methods for flood risk estimation. Rainfall- runoff and empirical equations are among the most used methods. In these methods, rainfall is the main parameter influencing flood mechanism. In this research, spatial distribution of rainfall pattern in Esfahan province is studied. Esfahan province with 10.5 million hectars of area has located in the central part of Iran with different topography, climate and ecological condition. Over 203 rain-guages located in the study area and its neibourhood were studied. The duration base of data record was 33 years. A total of 1654 storm events with less than 1 hour to 72 hours duration were considered, in which three index events, i.e. widespread and maximum events were used. The common methods of geostatistics, Krigging, Co-Krigging, IDW and TPSS were applied to interpolate the recorded points to non-observed ones. Among the studied interpolating methods, Krigging shows the best results, from which the Gussian and spherical models best fits to the observed points. In order to gain the best results, it is recommended to add the number of rainfall guage sites according to the World Meteorological Organization (WMO) standards. Also, we propose grouping the study area into homogeneous regions and studying DAD in each homogeneous region is advised.
