bohloul alijani

Iran is a country with low rainfall and high-intensity rainfall that is affected by various synoptic systems, the most important of these systems is Sudan low pressure, Therefore, recognizing the low pressures of the Sudan region is of particular importance, The purpose of this study is to gather a complete and comprehensive knowledge of the set of studies conducted about this low pressure, structure and formation and its effects on the surrounding climate. The present study was conducted using the library method and a search for authoritative scientific and research sources in connection with research on low pressure in Sudan and no data processing was performed in it. Thus, it has studied and analyzed the temporal and spatial changes of Sudan's low pressure over several years and its effect on the climate of the surrounding areas, especially Iran. In general, the results of this study can be divided into several categories, including studies on the recognition and study of Sudan low pressure, its structure and formation over time, pressure patterns affecting it at different atmospheric levels, and its effects on the climate of surrounding areas, especially Iran. Has been studied, The effect of this low pressure on seasonal and spring rainfall in Iran, snow and hail, floods, thunderstorms and also the effect of remote connection patterns on this low-pressure system have been studied, and finally, the analysis of these findings has been studied. It can be concluded that the Sudanese low-pressure system is a Low-pressure reverse in the region of Northeast Africa and southwest of the Middle East, which is strengthened and displaced in the upper levels of the Mediterranean and Subtropical jet stream and in the lower surface moisture injection from the Arabian Sea and Oman through high pressure. Saudi Arabia is inwardly the cause of severe instability in Iran and a major cause of heavy rainfall in various parts of the country.

Cold and frost are one of the climatic hazards that cause damage to various activities every year. Climate change, on the other hand, causes spatial and temporal changes in glaciation. The purpose of this study is to analyze the temporal-spatial changes and predict the future of glaciers in Hamadan province. CanESM2 model was used to predict the minimum daily temperature in the province. Data mining of general circulation models was Downscaling using LARS-WG model. The above parameters were simulated for a period of 30 years (2050-2021) under three scenarios RCP2.6, RCP4.5 and RCP8.5 for selected stations. The results of the monthly minimum temperature survey in the study stations of the province showed that the minimum temperature in the period (2050-2021) in all studied stations according to all three scenarios will increase in all months of the year compared to the base period. The average minimum temperature of the province is equal to 2.5 degrees Celsius, which in the coming decades based on the scenarios of RCP2.6, RCP4.5 and RCP8.5 will reach 6, 6.2 and 6.3 degrees Celsius, respectively, which is the highest The changes are related to Nojeh station and the lowest is related to Hamedan. The spatial distribution of the beginning and end of freezing in the future period indicates that freezing in the northeastern and northern parts of the province starts earlier and ends later than in other parts of the province, while in the southern parts of the province it starts later and ends earlier. The results of examining the changes in the onset of frost in the next decade compared to the base period showed that in all stations studied the onset of frost will decrease between 3 to 11 days.

Spatial variations of pressure patterns under the influence of large-scale atmospheric circulation create different conditions in terms of the intensity of synoptic systems affecting on extreme climatic phenomena. Regarding large-scale patterns, not only the changes of extreme events are considered, but also the changes and developments of synoptic systems on a regional scale are studied. Weather extremes have a great significance for society, as they pose a threat to human life and can result in enormous economic damage and disruption. The physical understanding and timely prediction of extreme weather events are of enormous importance to society regarding associated impacts. Extreme precipitation events (EPEs) is one of the most frequent natural hazards that affects the domain, eventually leading to floods. Synoptic systems in mid-latitudes such as blocking, ridge and troughs cause spatial changes in westerly waves. Spatial variations of atmospheric waves occur when, which normally move from west to east, change their main direction to the north or south. The occurrence of precipitation in the Middle East is related to the changes in waves and the position of the Mediterranean trough. Extreme precipitation events in the Middle East often result from tropical-extratropical interaction, whereby midlatitude forcing and poleward transport of tropical moisture are of central importance. The Mediterranean Sea region is considered to be one of the most important and major areas for circulation in the Northern Hemisphere, so that most of Iran's rain cyclones are formed over the Mediterranean Sea. In other words, Iran's rainfall in the cold period of the year is influenced by the Mediterranean circulation patterns. Evidence shows that the large-scale atmospheric circulation over the North Atlantic plays an important role in the Mediterranean circulation changes. We investigated the effect of mid-latitude atmospheric circulation changes on the position of the Mediterranean trough and the occurrence of super heavy precipitation in Iran. In this research, two category of upper atmosphere data were used. The first is daliy precipitation data for 350 stations that were made available by the Iranian Meteorological Organization (IRIMO). The second dataset is the geopotential height, relative vorticity, potential vorticity, U, V-component of wind and Relative humidity, extracted from the European Centre for Medium-Range Weather Forecasts (ECMWF-ERA5) reanalysis with grids at 0.25×0.25 resolution. In this regard, 150 extreme and widespread rains were identified, then using the sinuosity index, the changes of the most frequent contours (550, 565 and 575 decimeters) during the precipitations were identified over the North Atlantic and Mediterranean. The aim of this study was to find the relationship between the spatial variations of the upper level waves over the North Atlantic and the Mediterranean (-80° W to 70° E, 10° N to 60° N). According to sinuosity index, the minimum sinuosity value is about 1 indicating zonal flow. Any sinuosity value greater than 1 indicates an increase in atmospheric waves. The spatial changes of the Mediterranean trough are due to the meridian changes of currents over the North Atlantic, Europe. The blocking system over the Atlantic was responsible for both the amplification of the downstream trough, as well as the formation and expansion of the trough towards the Eastern Mediterranean. The results show that extremely heavy and widespread rains occur under the influence of the formation of the Mediterranean trough and the expansion of winds from the European side and the strengthening of the North Atlantic trough. The results showed that the position and changes of the Mediterranean trough are associated with the circulation pattern of the North Atlantic. Multiple Atlantic trough are associated with each case of Mediterranean trough downstream. The formation of the Atlantic trough causes an increase in the range of atmospheric waves and the formation of a ridge over Europe and the development of the Mediterranean trough. Under these conditions the Mediterranean Sea experiences 8 longitudinal and latitudinal changes compared to its average. Therefore, the spatial variations of the Mediterranean trough are due to the meridian changes of the European flows and the expansion of the high north side (tropical side) downstream of the western wind. Simultaneously with the formation of blocking over Europe in its eastern part, the dynamic ridge causes the transfer of cold winds over the Mediterranean, which strengthens and expands the Mediterranean trough to the east. These conditions, with the strengthening of the conditions of ascent and eastward movement of the Mediterranean trough, the Arabian Subtropical Anticyclone (ASA) also expands eastward. During the heavy rains of Iran, by strengthening the conditions of ascent and eastward expansion to the Mediterranean trough, the ASA also expands to the east. Therefore, with the location of the ASA over the northern Indian Ocean, the Arabian Sea, and the Oman Sea, more moisture is provided to the atmosphere, which is accompanied by the intensification of extremely intense and widespread precipitation. In general, the position of the Mediterranean trough during heavy rains is such that the western and southwestern regions of the country receive most of the precipitation. These conditions are more severe due to the orographic factor of ascent caused by the Zagros mountains in this region.

Evidence suggests that climate change will create uncertain regional agricultural production stability in the coming decades. This research investigated the impact of climate change on hydrology and sugar beet yield as one of the main crops in the Urmia lake basin using the Soil and Water Assessment Tool (SWAT). To address this, a baseline SWAT model was setup for 1986-2014. Afterward, the output was calibrated (1989-2004) and validated (2005-2014) in the SWAT-CUP software using the SUFI2 algorithm to simulate streamflow of 23 gauging stations and crop yield. The Nash-Sutcliffe efficiency was 0.43 and 0.53 for calibration and validation periods, sequentially. The Percent Bias was 45% and 16% for calibration and validation periods, respectively. As well as the agreement indices of 0.71 and the little Percent Bias (-6% to 10%) for crop production, verified the model's efficiency. The next step was downscaling and bias-correction of the precipitation and temperature data received from 3 climate models, namely GFDL, HadGEM2, and IPSL under RCP4.5 and RCP8.5 using CCT program. Then, the downscaled data were fed to SWAT, and Finally, hydrological fluxes and sugar beet yield were estimated for 2021-2050. Despite a dispersion of precipitation changes ranging from -12% to +35% in most scenarios, results highlight the pivotal role that the warmer temperature (+2.7°C) increases evaporation, resulting in sharpened pressure on water resources and runoff, especially, at the beginning of crop growth season. Finally, the negative impacts on crop productivity (-45%) is not unexpected. This means that sugar beet may suffer from climate change impacts, and the production of this plant will change over the next period in this region.

The purpose of this article is to analyze the frequency and severity of the one to six days of rainfall in Iran. The trend of frequency changes and severity of each course was identified using my-candle test and the slope estimator during the 1968-1988 period. Then, using the main component analysis method and cluster analysis method, the entire stations were categorized in five clusters (abundance) and four (intensity) based on the annual changes of frequency indicators and intensity of precipitation. Cluster 1 and 2 stations represent the frequency of precipitation periods with a severe or without trend. The two clusters were mostly established in the southern half of Iran. Cluster 4 and 5 stations represent the frequency of precipitation periods with a positive (mild) trend, mainly in the northern part of the country. Cluster 3 stations represent the frequency of precipitation periods with decreased (mild) trends, which are mostly focused on west and southwestern Iran. The clustering results of the stations based on the intensity index of precipitation periods, contrary to many results; do not show a specific pattern. But in the cluster, there has been a severe decrease in the last half century. The stations of this cluster are mostly concentrated in the northern parts of the country. Other clusters are scattered in almost all parts of the country. Accordingly, it can be concluded that the frequency of precipitation periods in the northern latitudes of incremental processes (average or weak) and the severity of precipitation periods in these latitudes (north of the country) had severe declining trends.

This study was aimed at examining the types of inversion and their severity using the thermodynamic indices of the atmosphere such as SI, LI, KI and TT at Bandar Abbas Station for 2010-2020. In this study, Radioosvand data at the Bandar Abbas Station was obtained and used from the University of Wioming for the last 11 years (3.5 local) during the last 11 years (2010 to 2020). The results of the analysis showed that the average number of inversion phenomenon in Bandar Abbas was 501 cases per year, as in some days several types of inversion were observed at different altitude. Of these inversion, about 31.6 % are related to radiation temperature inversion, 4.3 % front, and another 64.1 % for subsidence inversion. Due to the air session underneath, the share of subsidence inversions is more than other types of inversion. In the meantime, the most severe inversion of subsidence was 1354 and the weakest inversions were with 29 cases and fronts. In general, the long -term average intensity coefficient of inversion of Bandar Abbas station with a coefficient of 0.062 indicates that the intensity of the city's inversion is mostly extremely severe, which can be very destructive effects both environmentally and physical health in the city's residents. Bandar Abbas follow. The correlation between the inversion elements also showed that by reducing the thickness of the inversion layer, the intensity of temperature inversion also increased.

During the recent decades the discipline of geography has lost its priority and position to some degree in Iran. Most of the graduates could not enter into the work in the universities and other organizations. The human-environment system, the main area of geographical specialty - has experienced many crises and hazards among which the global warming and climate change being the most destructive. This means that the ongoing curriculum is not working well and needs to experience a fundamental change. To implement this operation some points should be cleared out: The hazardous condition of the world and especially Iran, the education history and state of geography in Iran, and the relation between geography and sustainable development of the world. The discipline of geography has changed its approach according to the circumstances of each period several times. For example, at the beginning of the twenty-century due to the dominance of the environmental determinism, the dominant approach of geography was the relation between man and environment. But since the 1970’s the earth has encountered with different hazards and crises to the extent that it is named as the period of Anthropocene. Accordingly, the dominant approach of geography during this Anthropocene era is to identify and solve the hazards and crises and lead the man- environment system towards the sustainability as once was requested by the secretary general of the United Nation. In this regard the geography should adopt the sustainable development concepts and goals. For this reason, the geography of Iran should make a switch from its very specialized approach to a relatively wholistic view and pay more attention to the human- environment paradigm. To implement this order, the following assumptions should be considered.

Climate is one of the most important factors in enhancing combat capability in military units. The purpose of this study is spatial analysis of climate hazards affecting military activities in the southern half of the country. For the study, data from 55 synoptic stations with a statistical period of 22 years were used. Dust storms, heat stress, heavy rainfall and sultry conditions were identified as the most important climate hazards affecting military activities in the study area. The frequency of days with dust storm in the north of Sistan and Baluchestan province and in Zabol and Zahak stations is the highest and in terms of temporal behavior, in late spring and summer has the highest frequency of occurrence. The highest frequency of heavy rainfall in the study area was in autumn and winter. Summer is almost the whole region with heat stress. In summer and spring, the highest frequency of sultry intensity has occurred in coastal stations. From the combination of fuzzy maps in GIS software, climate hazard maps were extracted seasonally and annually. In spring and summer in northern Sistan and Baluchestan province and in autumn coastal stations were recognized as the most unfavorable place and winter as the best time for military activities in the southern half of Iran. Khuzestan province, which has a high frequency of heat stress, sultry intensity and heavy rainfall at the same time, is the most undesirable place for the establishment of military units on an annual basis.

Precipitation is a phenomenon resulting from complex atmospheric interactions and among climatic events, due to its vital role, it has special importance. The importance of precipitation durability, especially in arid and semi-arid regions, which includes most of Iran, is greater than its volume. The purpose of this study is to identify Iran's precipitation areas in terms of precipitation durability and its characteristics in each area. In order to investigate the durability of Iran's precipitation and to define a precipitation day as " a day with equal precipitation or greater than 0.5 mm", used from daily precipitation data of 80 synoptic stations of the country during the 6 cold months of the year from October to March in a period of 30 years (2016 - 1987). Setting data in daily tables in the first step, made possible to program in MATLAB environment to separate precipitation in ten groups from "one day" to "ten days" and in the second step in SPSS environment based on frequency characteristics, amount and precipitations average in the mentioned groups was done by the method of Ward merging and clustering. The process of the clustering on Iran's durability precipitation showed that there are seven almost homogeneous precipitation zones in Iran; the geographical arrangement of Iran's precipitation areas, reveals the dependence of Iran's precipitations amount on roughness, the path of precipitation systems, its proximity to humidity sources, and the effect of the sea. In terms of area’s location, it can be said that; the settlement of the four zones in the western half of Iran, despite its small size in front of the eastern half, is a reason for its heterogeneity.

The effects of theTropical extratropical interaction (TEI) on the extreme and widespread precipitation of IranAbstractThis research was conducted with the aim of investigating the role of the interaction of tropical-extratropical circulation patterns on the extreme and widespread precipitation of Iran. To this end, 9 days with the extreme and widespread precipitation in Iran were investigated the 95th percentile index and their occurrence in 20 percent of stations and more during the statistical period of 31 years (1989-2019). Atmospheric data were extracted over 9 days. The data used are ERA5, which were extracted in the lower (850 and 800 hPa) and middle (700, 600, 500 hPa) levels. Geopotential hight jet stream maps show the tropical influence of extratropical dynamic factors, the amount of which is different in different levels of the atmosphere.Tropical and extratropical interaction have provided two factors for the occurrence of precipitation, i.e. humidity and atmospheric instability over Iran. The tropical influence of the Cut off low ,troughs and polar jet stream currents Their convergence with high-altitude subtropical centers have led to the transfer of tropical moisture to extratropical. On Iran, the influence of cut off low, the western trough and the polar jet stream provide suitable conditions for the ascent and instability of the atmosphere, which, with the entry of the tropical moisture of Iran, widespread and extreme precipitation occur.Key Words: circulation patterns, tropical and extratropical regions, tropical extratropical interaction, extreme widespread rain, Iran

The smallest change in energy exchange of Earth System Shifts the balance of life. In order to be aware of the solar radiation Balance, Recognition of the measure of Balance level of the input and output components of radiation of input Short wavelength to the surface of the earth and Long Output Wavelength, it is necessary from the earth. To study the energy balance of input and output in Iranian plateau, the input and output radiation data of NCEP / NCAR site was used With a resolution of 2.5 * 2.5 *, including 46 cells in Iran,. For each season, a representative month was considered And correlation, confidence level, coefficient of determination and amount of oscillation of input and output radiation were calculated in different regions of Iran. Finally, some calculations were presented spatially with the IDW method. The results showed that the maximum short-wave wavelength was 230 watts per square meter in August and the lowest was 52 watts per square meter in November. The highest long-wavelength output in August was 65 watts per square meter, and the lowest amount was January and November with 20 watts per square meter. The highest the amount of output increase has been occurred in August in the east of province South Khorasan with a correlation of 0.59 to 112 watts per square meter in 2001. In decreasing output changes, except for May, there was a decrease in the rest of the months. The highest long-wavelength output was in the northwest and in the provinces of Ardabil and Guilan.

According to the complexity of planetary-scale mechanisms affecting extreme snowfall events, the necessity of recognizing and studying the effective components of these climatic mechanisms are presented. Due to the role of the polar vortex of northern hemisphere in tropospheric variability in winter and also, in variability of the structure of the teleconnection patterns on intensity and weakness of the polar vortex, revealing the mechanism of impact of the two mentioned components on synoptic patterns leading to extreme snowfall events in Iran was considered in this study. According to the environmental approach in this study, first the snowfall days were identified and the atmospheric circulation patterns related to these days were investigated. For this purpose, daily data on rainfall and winter temperature (December-March) of fifty Iranian synchronous stations in the statistical period 1951-2016 were received from the Meteorological Organization of Iran. Atmospheric data and teleconnection indices were also obtained from the NCEP / NCAR. Finally, five periods were identified, during which snowfall was recorded in at least six stations and their average snowfall reached more than 20 mm. Of these event periods, which were in January and February, three periods related to January were examined in this study, which occurred in 1972, 1988 and 2008. In the second stage, atmospheric patterns were drawn in combination and for the average of the event periods, in three scales of hemisphere, synoptic and expanse of Iran, in the GrADS system Then, the amount and status of the teleconnection indices including: NAM, AO, NAO and PNA were analyzed in the period of extreme snowfall events. The emphasis of this study is on the effect of mid-tropospheric conditions in terms of altitude, temperature and altitude on snowfall events in Iran, while the patterns of pressure and temperature of the earth's surface and the humidity of the lower troposphere have also been considered. In hemispheric-scale combined patterns, the emphasis has been on showing the status of the tropospheric polar vortex in relation to teleconnection indices. In the third step, by doing a combined analysis, the effect of polar vortex on the change in teleconnection indices and their effectiveness on the formation of synoptic patterns leading to extreme snowfall events in Iran was revealed. According to the research findings, the NAM index, the strength of the center of the polar vortex and the AO index have shown the shape of the vortex in terms of its concentration or elongation. The PNA index has also been associated with the strength of northwestern Europe and the North Pacific anticyclones, which have contributed to the formation of blocking systems due to the northward deflection of the extending trough of polar vortex from their axial direction. The NAO index also represents the emergence of systems in the Euro-Atlantic section. The results showed that the necessary dynamic conditions for all three events have provided the emergence of blocking patterns due to weakening and distortion of the polar vortex. These events are often associated with disconnection of jet stream in the Eastern Hemisphere, especially in the Euro-Atlantic area. Hence, NAO and PNA indices, directly and NAM and AO indices indirectly affected the conditions required for extremesnowfall events in Iran.

Autumn and winter rains play an important role in Iran's agricultural and livestock economy, as well as feeding underground water tables, especially in the western and southwestern regions of Iran. The continuous reduction of underground water reserves in Iran increases the importance of atmospheric precipitation especially during autumn and winter seasons. This importance is affected by the centrality of agriculture in Iran, as well as the supply of drinking water in small and large cities.
This sensitivity is more in the southern half of Iran and especially in the southwest, which has rivers full of water and it, is a region full of large dams.

In this research, the mechanism of rainfall in the two seasons of autumn and winter in southwestern Iran was investigated and compared. Then, the synoptic conditions of the longest and most intense rainfalls that occurred during the selected data period in the research area were identified. In this research, a rainy day was defined as a day when the weather station received at least half a millimeter of rain. Also, the duration of rainfall at each station was defined as the number of consecutive days of rainfall at that station. In first step, daily rainfall data were collected from 8 weather stations in the 30-year period (1987-2016) in southwest Iran. During the second step, separation of rainfalls according their duration using programming in MATLAB environment; it made it possible to select 40 precipitation samples. During the last step, synoptic patterns were designed from daily weather maps, including moisture flux, atmospheric height, and the position of jet-stream cores.

In this research, the analysis of patterns showed the following results 1) Sources of continuous and widespread rains in the autumn season, warm waters around Iran include the Red Sea, Gulf of Aden, Arabian Sea, Persian Gulf and Oman Sea. 2) The origin of the wet currents of these rains is from the central regions of tropical Africa. 3) During the winter season, these resources are generally limited to the Red Sea and the Gulf of Aden. 4)  Also, the analysis of the position patterns of negative omega cores at the level of 500 hPa indicates the conditions of inflammation and severe thermal gradient in the atmospheric column over the southwestern lands of Iran during the autumn season compared to the winter.

Based on the designed patterns, the western troughs in the eastern Mediterranean deepen during the winter season compared to other seasons and they provide the following conditions for rainfall in southwest Iran: 1) The path of precipitation systems also reaches the southwest of Iran. 2) Stronger cores are formed from jet-stream in the southwest of Iran. 3) More water areas such as the Mediterranean Sea, the Red Sea, the Gulf of Aden and the Arabian Sea contribute to the provision of rainfall moisture.

In large and industrial cities, thousands of heavy metal particles are released into the environment [2]. These heavy metal particles are released by attaching to dust particles on a large scale [3]. It is important to study heavy metal concentrations in the dust falling due to the threats for human health [1, 4, 5]. Dust originates from both natural and human sources. Studies have been conducted to investigate the sources of heavy metal emissions in street dust with cluster analysis [CA] and principal component analysis [PCA] methods. The metropolis of Tehran has a population of over eight million people, that facing a severe air pollution problem. Therefore, the purpose of the present study was to identify the factors of increasing the heavy metal concentrations (Al, As, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Se, Si, V, Zn) in the dust falling of Tehran city.

Dust fallout samples were collected with using Marble Dust Collector (MDCO) from 28 different locations across the city of Tehran, during winter of 2017. XRF analysis used to identify and determine the concentration of heavy metals. The Principal Component Analysis (PCA) method were summarized 15 heavy elements studied into three factors. The kriging interpolation method was used to determine the role of each factor in the study area. In the next step, the extracted factors were grouped based on factor scores, by statistical method of cluster analysis.

The results of the Principal Component Analysis (PCA) showed the existence of three factors: natural, human and combination of natural and human factors which increasing the concentration of heavy metals in the dust of Tehran metropolis.
Factor 1: Aluminum, chromium, iron, magnesium, manganese, nickel, silicon, and vanadium have the same emission source. These factors are not affected by human activities but have natural origin. Therefore, this category was called the natural factor.
Factor 2: Arsenic, cadmium, copper, lead, and selenium have the same emission source. Probably, human factors have role in increasing these elements in the dust falling.  Therefore, this category was called the human factor.
Factor 3: Cobalt and zinc have the same emission source. This factor is combination of both natural and human factors.
Based on the extracted factors and with using method of Cluster Analysis (CA), the stations in Tehran were classified into four clusters as follows:The First group: Forest and Range Organization of IRAN, Dadman Blvd, Pole Gisha, Arash Blvd, Majidiyeh Shomali, Janatabad, Shahre Ziba, Pole Kan, Motahhari, Narmak, Hashemi, Tehransar. These stations are located in the northern and western regions of Tehran.
The second group: Afsaria station is located in the southeast of Tehran. This station has the highest concentration of heavy metal in dust falling.
The Third group: Velenjak station is located in north of Tehran. The heavy metal concentrations in dust falling are higher than other groups in human resources.
The Fourth group: Enghelab, Darvaze Dolat, Imam Hossein Square, Nawab, Si-e-tir, Komeil Gharbi, Tehranno, Piroozi, Nazi Abad and Shahr-e-rey are located in this cluster. These stations are located in the central, eastern and southern regions of Tehran. The concentration of heavy metals in these regions are high.

Heavy metals in dust are an important component of urban pollution. The harmful effects of heavy elements on human health have been proven in different ways. Considering the population of Tehran metropolis, the results of this research are very important for developing management approaches to create a healthier environment. The results showed that the pollution of dust falling into heavy metal with human origin in the northern and western regions of Tehran is less than other regions and in the southeast of Tehran is more than other regions. results indicated that population density, traffic and traffic volume, industries and mines, topographic pattern, vegetation pattern, prevailing wind pattern and air stability are effective in the concentration of heavy elements in Tehran dust falling.

The relation between society and environment has gone through different phases. During the years before the World War II, the environmental determinism controlled this relation. However, after the 1950’s the anthropocentrism replaced the environmental determinism and humans began to overuse the nature in such a way that nature lost its sustainability and many hazards and crises occurred. These destructions were so intense and widespread that some researchers compared with the episodes of geologic time and named the era beginning from 1970’s the Anthropocene epoch. During this period, the planetary boundaries were crossed in some areas such climate change, nitrogen cycle and biodiversity. Climate change has created most of other hazards. To overcome these problems in 1978 the Brandtland report   announced the sustainable development as not to spend resources more than the nature’s production capacity and not to pollute the nature more than it can assimilate. In other words, the nature should remain in its sustainable state so that the future generations can live with no limitations. The principles of the sustainable development were defined in the earth summit of Rio in 1992 such as social equity, economic viability, and environmental sustainability. These principles were broken down in 17 goals. The Rio conference asked all countries to achieve the sustainable development goals by 2030.  Methodologically the sustainable development requires integrated multidisciplinary approach to investigate the complex system of human- environment in different temporal and spatial scales to achieve the social equity, economic viability, and environmental sustainability. For this reason, many disciplines such as natural resources, environmental sciences, ecology and geography have contributed to the field. Different data from natural resources, human needs and drivers and environmental changes are required to process in very complicated models. In addition to different variables, the hazards are very important component of the sustainable development research, which also requires multi-aspect complicated approach and models. Spatial dependency is another aspect of sustainable development as it differs from place to place in many characteristics. In brief, from the spatial perspective the sustainable development is an integrated multi-approach research about the human-environment system to establish the sustainability on the earth. All of the related fields should study the sustainable development in collaboration with each other. However, the geography due to its long history of studying the relation between human and environment and its spatial dependency is the best single scientific field which can afford studying the sustainable development. Since the earliest times geography has developed quantitative methods, spatial techniques such as geostatistics, and environmental ethics to conserve the nature and human prosperity. The multi approach and systematic works are the main characteristics of Geography. On the other hand, Geography’s vision of defining the location for human’s activities while saving the nature’s sustainability covers the sustainable development completely. Therefore, geography is the overarching field for the sustainable development and it is the main intention of geographers to research and implement the sustainable development to reduce the environmental hazards and develop the sustainable environment for all the human beings at present and in the future. Geography studies the sustainable development through three steps including spatial analysis, spatial planning, and spatial management. In addition, geographers should learn different skills such remote sensing, multivariate statistics and above all develop a common language between different branches of geography.

Precipitation plays a fundamental role in the survival of Earth's systems and provides water to sustain life on earth. The importance of precipitation durability, especially in arid and semi-arid regions, which includes most part of Iran, is greater than its volume. The aim of this study is to identify the rainfall regions of Iran in terms of rainfall durability and to investigate the characteristics of rainfall durability in each region. in order to investigate the durability of Iran's precipitation and by defining the day of precipitation as "Day with a rainfall equal to or greater than 0.5 mm", the daily precipitation data of 80 synoptic stations in the country during the cold 6 months of the year from October to March over a 30-year period (1987-2016) used. Setting the data in daily tables in the first step, enabled programming in the MATLAB environment for separating precipitation into ten groups from "one-day" to "ten-day". And in the second step in the SPSS environment based on frequency characteristics, amount and mean of precipitation in the mentioned groups, clustering done by WARD method were merged by clustering method. Implementation of clustering process on Iran rainfall durability showed that there are 7 almost homogeneous zones in Iran based on rainfall durability; which the effect of inland and outer climatic factors including latitude, roughness, path of precipitation systems and distance to moisture sources is evident that with declining the last three factors, these zones become more homogeneous in the eastern half of Iran. One of the projectable hazards is that the supply of atmospheric precipitation, especially in east of Iran, is more in charge of short durable precipitation. In fact, the one-day and the two-day low precipitations are dominant in the western part of the country and in terms of the proportion of durability in the eastern half of Iran. This finding shows the general inefficiency of the country's water resources management plans with the macro approach of storage the surface water.Key words: Spatial patterns, Precipitation durability, Rainy day, Iran

Global warming and climate change are very important issues of the last century, which have been considered by scientists in various fields of science. The Hyrcanian forest is one of the oldest and most historic habitats of the world's deciduous trees. Beech trees are one of the valuable industrial species with a lifespan of 200 to 300 years. The science of tree chronology can show past weather events. The diameter of the annual growth rings of the trees forms a time series. With this method, a time series of 202 (1816-2017) years was obtained from the diameter of the growth rings of beech trees.Researchers are always thinking about the future. This study uses time series of growth rings of forest beech trees and analyzes it.And the use of modeling based on the Box-Jenkins method with emphasis on ARIMA models were examined. The results showed, Time series with ARIMA model (1,1,1) had the best fit, at the 95% level, it is significant and the trend forecast has a negative and decreasing slope. Climatic factor of annual precipitation in the regional station and neighboring stations with a decreasing and negative trend The average minimum, middle and maximum average temperatures are increasing. Climate change is reducing growth for Hyrcanian forest trees. It was registered as the second natural heritage of Iran in UNESCO. It will pose a threat to plant and animal communities.

Urbanization represents the most dramatic human alteration of the land surface, typically resulting in the formation of urban heat islands . Land surface temperature (LST) is a key parameter for surface energy balance and urban climatology studies. Understanding the spatial distribution of temperature is the basis for proper planning and environmental policy making. In this study, using Landsat 7 satellite imagery in two time periods of base year (2017-2010) and second interval (2000-2005) were used on average in three warm months of the year Then these images were first geometrically corrected; then these images were used to calculate temperature-related parameters using a single-window method in Gorgan. It was then used to improve the accuracy of the work using the hourly temperature data of the thermal islands analyzed. The results show that temporal and spatial variations of thermal islands in Gorgan have a high cluster pattern. However, the local Moran index and hot spots in the north, northwest and east and downtown have a positive spatial correlation (hot spots). However, there are cold spots in the southern areas of the city. However, many parts of the city of Gorgan have no significant patterns or spatial autocorrelation during the study period. It can be said that the thermal islands of Gorgan depend on two factors: one is the prevailing climatic conditions in the period under study and the second is the prevailing humanitarian conditions in the city. climatic conditions in the period under study and the second is the prevailing humanitarian conditions in the city.

Corona Virus pandemic outbreak is the counter act and warning of the natural environment for the destructive activities of man in the nature. Many researchers and specialists believe that  a risk free and sustainable life is possible if we correct our behavior toward the nature. This research was carried out to substantiate this hypothesis and offer a reasonable and rationale solution. It is believed that the best way to solve this problem is the environmental ethics. Many other ways such as technology have been proposed, but until the mind and thought of man has not changed to good relation with the nature, it is not possible to reach a viable solution. For this end, the integrated system of earth was analyzed to understand mechanism of the relation between nature and human. Two supportive theories of Markov Blanket and Gaia were addressed here to explain the relation between nature and society. According to these theories the system of earth and society is live and any change in one will mirror itself on the other. As a result, the society models itself to the nature in long run. This means that to have a healthy society we should have a healthy nature and environment. Thus, the UNEP has suggested the integrated One Health program to save nature, humans and animals at the same time.  The distortions of the earth during the past 70 years were sampled and described as the footprints of mankind. Some examples of environmental disorders such as climate change, droughts, floods and diseases were analyzed and their impacts on the society were displayd.In order to demonstrate the environmental ethics as the only solution to the current crises, first the ethics in general were discussed and then the environmental ethics were given a thorough explanation. Different underpinning philosophies are presented and accordingly different approaches to the nature such as development, preservation and conservation were discussed. A new philosophy, geocentrism, was suggested as the suitable and efficient thought. According to this philosophy it is the distributions which are in the forefront of human destruction. Therefore, we should try not to disturb the distributions of any kind. These include all ecosystems of any scale; because emphasizing on the ecosystems is not sufficient. The geocentrism philosophy covers all non - anthropocentrism philosophies such as biocentrism and ecocentrism. Of the different approaches, the conservation was selected as it assumes intrinsic value for the nature and sustainability of resources for ever. To solve the problem and bring the earth system to sustainable state, the environmental ethics should be implemented. In terms of moral values, these include truth, good, duty and justice. The mankind should characterize himself with these genuine characters. He should do his duty as not making problem to the life of any creature; this being human, plant, animal or rock and soil and etc. He should do the good and justice. On the objective side, he should give intrinsic value for every creature on the earth including the environment and its components. In this way, we treat the environment with respect and dignity and not let ourselves to destroy or damage it. However, to achieve these goals we should use resources only as much as we need biologically, consider the long run benefits instead of short term benefits, treat the nature as having intrinsic value, implement the environmental distance from wild life, using vegetarian diet. One important notice is the nature of human who we are asking to do these mandatories. Are we sure that what we are ordering human will be done by him. If he does not do then none of these comments is valuable. Therefore, we first should understand the humans and educate them to accept our orders. This is why that the ethics become important. We should train moral humans and then ask them to do. He will do only when he gets overarching and believed knowledge   about the subjects we are offering. The main reason for the distortion of the nature is that the humans are not aware of the value of nature and the long run results of their actions. This is possible only through the good and responsible training of man. We are now missing this education. In brief, we understand that the main solution for the destruction of nature is empowering the humans with morals, especially environmental ethics. But to implement this objective, at the first point we need a wise and understandable human. Therefore, first we should train people and ask them to act as a moral and generous person and care for the nature and all creatures of the universe.

In this study, the relationship between mean zonal and meridional variations of westerlies with wet and dry periods in the western Iran was investigated. Therefore, the data cumulative precipitation values of the study area from Eropean Center for Medium-Range Weather Forecasts (ECMWF) version (ERA-Interim) with spatial resolution of 0.125*0.125 and also the geopotential height data of the version ERA5 with a spatial resolution of 0.25*0.25 degrees was received from the same center for the years 1979 to 2019.The Standard Precipitation Index (SPI) was used to determine the monthly wet and dry periods. So, to investigate the relationship between mean zonal and meridional variations of the westerlies with wet and dry periods in western Iran, the Middle East Synoptic Index (MESI) was defined based on variations of the westerlies from 25 to 45 degrees north latitude at atmospheric levels of 500, 600 and 700 hPa. The results indicated, that when wet periods occur in western Iran, MESI upper than the threshold and westerlies on the Middle East (Mediterranean and Red Seas) have a meridional flow. Whereas in dry periods, MESI is lower than the threshold and westerlies have a zonal flow. According to the results, no wet and dry periods was found, the value of which MESI was lower and upper than the threshold. Therefore, it seems that variations of the westerlies flow can be effective as one of the factors in formation wet and dry periods in the western Iran.

Climate predictions have been made in global, regional and local simulation, and climatic parameters have changed in terms of trends and models in climatology, futures studies are less visible in literature and climatology literature therefore environmental planning and futures analysis are an attempt to look at the long-term future in the field of climatology. Today, one of the most important challenges of the present and future is the increase in temperature and   is the lack of climatic comfort. The growth of Tehranchr('39')s metropolitan area, improving living standards, expanding urbanization and industry, climate change, and the energy shortage crisis are important. The survey forms were prepared by the climatologists and managers of Tehran and data analysis, futuristic techniques such as scenario for data analysis tool in this study was MICMAC software. have been used. In the research process, the most important key factors and drivers in relation to futures studies were identified in relation to the increase of temperature in the city of Tehran.Mini scenarios and a comprehensive scenario were defined in three cases: Improvement of the Micro-Climatic Conditions of Tehran City + Climatic Comfort of Citizens Lack of  good micro-climate in Tehran + low climatic comfort of citizens The lack of improvement in the micro-climatic situation in Tehran + the lack of climate comfort for citizens and increased energy consumptionAccording to the results of the study, the most important factors in creating a crisis of rising surface temperature can be the lack of attitude to the concept of micro-climate improvement and urban management.

The city, as a multifaceted phenomenon, has various dimensions. One of its most important dimensions, which has always been one of the debates raised in urban design and planning, is its geometry. Urban geometry and the geometry of urban valleys, which are defined by changes in height, length, and distance of buildings, significantly affect energy exchanges and thereby the temperature of urban areas. Changes in urban geometry will lead to some problems and issues, one of which is climate change on micro and medium scales. The geometry of the city has always been of interest to climatologists due to its effects on the urban climate. One of the important parameters of it is the Sky View Factor (SVF). Although urban climatologists know this factor well, it has not been properly raised among urban planners. On the other hand, since this factor is related to other climatic variables, it can play a key role in urban decision-making. Therefore, in the present study, it is attempted to present and classify the methods and techniques used for calculating this factor, while examining the need to pay attention to it. Therefore, this study aims to identify and study the types of this factor and then to study and classify various calculation and estimation methods. The results of this study show that the calculation and estimation of SVF have started with photographic and analytical methods and increasingly expanded with software and GPS methods. Also, at the end of this study, a classification of the background of the topic, along with various calculation methods and techniques and related software, is presented in a table in detail.

Air pollution and climate change are two of the most serious problems facing human societies which interact with each other through radiation, dynamic and chemical processes. Increasing air pollutants some as greenhouse gases in addition to adverse effects on health, economic and social sectors of societies, during chemical and photochemical reactions in the atmosphere, disrupt the Earth's energy balance and cause radiation forcing and rapid negative climate gains, such as global warming. With the recent climate change the quality of life of urban communities is also facing a serious threat. With the importance of this issue and with the aim of achieving a unified approach to reducing air pollution and mitigating climate change, it is essential to know the quality of major air pollutants in the face of recent climate change. In this study, long-term data (2002-2017) of Tehran Air Quality Control Company were used for analysis of annual, seasonal and monthly air quality conditions and changes of trends of air pollutants concentrations and the air quality index (AQI) of six major air pollutants .Also, for the statistical analysis, linear regression model, frequency distribution and calculation of variation percentage were used. According to the results, the air quality of Tehran is in a poor condition due to concentrations of more than two to four times the national and international standards of most pollutants (except CO and SO2 which have improved). So that during 16 years of study according to the highest values of AQI and the highest frequency of contaminated days, three general air pollution periods (2002-2006:CO), (2007-2009: ), (2010-2017: ) were determined for Tehran. Accordingly, the third period with an (11%) unfavorable growth in average annual AQI and a decrease (-19%) in total frequency of desirable days (-184% clean, -13 healthy) and increase (33%) in total adverse days, especially unhealthy days for sensitive groups (35%) was the most affected period compared to that of the other previous two periods. In the third period of air pollution only about (2%) of the days of the year were at the clean level and more than one third of the days (36%) with the criteria air pollutant  contaminated. Also, seasonally due to the influence of the specific weather conditions of each season on the exacerbation of adverse pollutants status, two peak of pollution in cold and hot periods of the year were determined. In hot seasons,)41%( of the annual contaminated days were recorded, especially in summer (%23) due to high concentrations of pollutants (  (70%),  (27%) and  (3%)). The monthly pollution peaks of this period are also in June, July and August respectively. The peak of pollution in cold period of the year was designated as the most polluted peak. During this period, 59% of the frequency of adverse annual days, especially in winter (31%), was recorded due to high concentrations of pollutants (87%),  (10%)and  (3%) have been in December, January and February respectively. Also, in recent years (2010-2017), the winter pollution peak has been associated with a )24%( increase in the quality index and 70% in the frequency of contaminated days. Therefore, due to the direct and indirect effects of air quality pollutants in the face of aggravating climate change, in addition to the need to further reduce long-term greenhouse gas emissions in related policies, formulating stricter strategies to reduce pollutants emission in urban areas as Tehran should be improvised.

The climate of the earth has begun to warming since 1980’s which has created very serious problems for the human living and natural environment. As a result the study of the global warming and its solutions has become the focal point of the climate change research all over the world. The climatologists are trying to understand, predict and finally give solutions to it. Many different models have been developed to predict and project the future climate conditions among which the Regional Climate Model is to some degree has lower values of uncertainty. The impacts of climate change is relatively higher in the naturally dry climate of the Middle East including Iran. Here the main parameters of the climate that is temperature is increasing and precipitation decreasing. As a result the projection and understanding of these two elements are very important for the region and Iran. For this reason this studyhas focused on the efficiency of the Regional Climate Model in projecting the future climate of the region and Iran.

In order to test the efficiency of RegCM 4.3the monthly temperature and precipitation
Data were extracted for the window 24N-40N and 43E-64E from the ECMWF database with spatial resolution of 2.5 degrees. These data were compared and corrected with the station data of Bandar Anzali, Bandar Boushehr, Mashad, Tehran, Yazd, Zahedan, Khorramabad and Zanjan . The simulated model data for RegCM 4.3were extracted for the same period and area with the same spatial resolution. Both data were transported into the Matlab environment and compared.

Results of simulated RegCM 4.3data were compared withobserved data of eight stations. The temperature data were slightly (about 2 degrees C) more than observed data. But the precipitation projections were somewhat complicated. The values of rainy stations such as Anzali were overestimated ( about 257 mm) while  that of most dry stations such as Zahedan were underestimated (about 58 mm).  But the RegCM 4.3 simulations were the same as the observed data inthe normal stations such as Zanjan. The results showed that the RegCM 4.3is suitable for projecting temperature data more than the precipitation. This is in agreement with the findings of many other studies.

The plant community in an area is the most sensitive indicator of climate. A visual comparison of climate and vegetation on a global scale immediately reveals a strong correlation between climatic and vegetation zones and this relationship, of course, are not co-incidental.  The main object of this study is to reveal the spatiotemporal association between climatic factors andvegetation Cover (NDVI) incorporate MODIS and TRMM product in Kohkiloyeh O Boirahmad province of Iran. So that the in this paer we use MOD13Q1  of MODIS product as NDVI layer for study area. MOD11A2 as landsurface temperature and 3B43 TRMM as meanmonthly accumulative rainfall for study area during 2002 to 2012 in 0.25° spatial resolution also were used as climatic factors. We use the correlation and cross-correlation analysis in 0.95 confident level(P_value =0.05) to detection the spatial and temporal association between the NDVI and 2 climatic Factor(LST and rainfall). The results indicated that during winter (December to March) the spatial distribution of NDVI is highly correlated with LST spatial distribution. In these months the pixels which have the high value of NDVI are spatiallyassociated with the pixels which have highest value of LST (6 to 14C°).As can be seen in table 1. Season the spatial correlation among NDVI and LST is so high which is statistical significant in 0.99 confident level  in winter. In transient months such as May, October and November,(temperate months in study region ) the spatial correlation among NDVI and LST is falling to 0.30 to 0.35 which is not statistical significant in 0.95 confident level. Finally in summer season or warm months including Jun to September, we found the minimum spatial association among the NDVI and LST.. In temporal aspect we found that the maximum correlation between NDVI and LST simultaneously appears and not whit lag time. The spatial correlation of NDVI and TRMM monthly accumulative rainfall was statistical significant in spring season (April to Jun) by 1 month lag time in remain months we don’t find any significant correlation between NDVI and rainfall.