فهرست مطالب علی شاهبایی کوتنایی

Identifying the behavior of precipitation is one of the most important planning principles related to water resources. In this research, an attempt was made to analyze the trend of time changes in extreme rainfall profiles of the country by using the daily rainfall data of 3423 synoptic, climatology, and rain gauge stations for the period from 1970 to 2016 and by performing interpolation using the kriging method. Then, using percentile profiles (percentile less than 10, less than 25, 25 to 75, 75 to 90, and above 90) and regression analysis, changes in the frequency of member days of each of the percentile methods over time were calculated and mapped. The results showed that during the studied period, 86.6% of cells associated with days with the tenth percentile or less in the country had an increasing trend. On the other hand, the pixels associated with days with the 90th percentile and more have shown an increasing trend. Considering that the pixels with the 25th, 25th-75th percentiles (normal), and 75th percentile have shown a decreasing trend in terms of the number of days in their group, it can be concluded that the country's rainfall conditions and the days with rainfall are towards the limit values has moved and the possibility of drought or destructive floods has increased in the country.

Precipitation is one of the main elements of the Earth's hydro-climatic cycle and its variability depends on the complex and non-linear relationships between the climate system and environmental factors. Understanding these relationships and doing environmental planning based on them is difficult. Therefore, classifying data and dividing information into homogeneous and small categories can be helpful in this regard. In the present study, an attempt was made to prepare precipitation, altitude, slope, slope direction, and station density data for 3423 synoptic, climatological, and gauge stations in Iran in the 1961-2015 years’ period. These data were entered into fuzzy (FCM), self-organizing map neural network (SOM-ANN) models and precipitation-spatial zoning. The outputs of the two models were compared in terms of accuracy and efficiency. The results obtained from the output of the models have divided the rainfall conditions of Iran into four zones concerning environmental factors. Evaluations also showed that both models had high accuracy in classifying precipitation parameters; However, the fuzzy model has a relative advantage over the neural network model in the accuracy of results.

Precipitation is one of the most significant climatic parameters; its distribution and values in different areas is the result of complex linear and nonlinear relationships between atmospheric elements-climatic processes and the spatial structure of the earth's surface environment. Classification of data and placing them in small and homogeneous zones can be effective in improving the understanding of these complex relationships and their results. In the present study, zoning and analyzing the distribution of rainfall in Iran concerning environmental factors was performed using the annual precipitation data of 3423 synoptic, climatological, and gauge stations in the country during the period from 1961 to 2015 and the altitude, slope, aspect, and station density data. After standardization and preparation of the data matrix, the optimal number of clusters was determined and the data set was entered into the neural-fuzzy network model (ANFIS-FCM). The results showed that the values of R2  and MAE  indices were 0.76 and 0.23, respectively which indicate the appropriate accuracy of the model. It was also found that in the four output zones of the model, environmental factors have a high impact on the spatial distribution of precipitation. In the first and third zones, the combination of high altitude and slope factors along with geographical proximity to precipitation systems has caused the average annual rainfall in these zones to be 318 and 181 mm, respectively. The mean annual rainfall has decreased to about 100 mm by the weakening of the role of environmental factors in the second and fourth clusters.

In the present century the increase of population, the need for more food, increasing environmental pollution, the use of new and renewable energy, including wind more human attention. Iranchr('39')s special geographical position, take advantage of this to provide clean energy and it is economically cost effective. In the present study to determine the potential assessment, the use of wind energy in the countrychr('39')s desert areas and desert, from hourly wind speed and position data in the period 1987 until 2015. After the control of quantitative and qualitative data, maps of spatial changes of wind speed and spatial analysis using the method of including the local Moran, the potential use of wind energy in various parts of the region was classified. The results of the investigation showed that the provinces of Kerman, Sistan and Baluchestan, and Hormozgan, the southern parts of South Khorasan and Yazd, including areas of the East and South are prone to install wind turbines and wind energy received. In the continuation of the investigation it was determined the maximum wind speed in the region in the early hours of the day to early afternoon (hours are 9 am-15 pm) occurs resulting in the greatest amount of energy available in the extraction interval. An important point is that during the investigation it was determined the necessity of paying attention to the potential of coastal areas in the field of wind energy supply. The special climatic and geographical characteristics of these areas has been caused at all times of the day witnessed a relatively strong winds and persistent winds from a high potential for energy supply.

Rainfall is amongst the most important climatic elements with a lot of spatial and temporal changes; in contrast to the other climatic phenomena, rainfall features more notable movement complexity. The studies performed in this regard indicate that such a climatic element as rainfall features a non-stationary behavior with a vast part of this non-stationariness being the result of the rainfall’s being influenced by the spatial properties and the complex pattern of the spatial organization causes the emergence of complex behaviors in the precipitations. The importance of the rainfall as the country’s water resource and the daily increasing reduction of the country’s water reservoirs demands the study of the rainfall’s behaviors. In the present study and by the assistance of the methods of spatial statistics, the spatial pattern of the spring rainfalls in the northwest of Iran will be elaborated. 
Data and

The study area of the present study is the regions in the northwest of Iran (Azerbaijan-e-Gharbi, Azerbaijan-e-Sharghi, Ardabil, Kurdistan and Zanjan Provinces) and, to perform the study, use has been made of the monthly precipitation data acquired from 121 synoptic stations as well as climatological investigations and precipitation studies for a period between 1994 and 2014.In order to perform the spatial analysis of the precipitations, use has been made of the digital map of the elevation in the environment of ArcGIS software for extracting slope and dip. In the next part and in order to analyse the spatial structure of the rainfall and investigate the degree of similarity between the data acquired from 121 station points, use has been made of the half pseudo-variance spatial correlation index. The Semivariogram has been estimated based on the arithmetic mean of the intervals.In the present study, use was made of the longitude and latitude of every station point and the rainfall rates of every point for delineating the empirical Semivariogram for three months, namely April, May and June in the environment of Variowin Software, version 2.2; then, various theoretical models were estimated in terms of their goodness of fit and the exponential model was selected as the best model for every month.In order to analyse the spatial factors influencing the spring rainfalls in the northwest, the balanced geographical regression model was estimated in terms of its goodness of fit with its output being the indicator or indicators influencing the occurrence of spring rainfalls according to the explanatory variables of slope, dip, elevation and latitude.

Following the investigation of the data related to April, it was made clear that the effect of the elevations on the rainfall variations is significant in this month in the entire parts of the region. The highest significant effect of the elevation has been in the central parts of the region for such a reason as the large density of the mountainous masses in this part and the passing of precipitation systems from these regions. In parts of the region’s north (north of Azerbaijan-e-Gharbi, Azerbaijan-e-Sharghi and Ardabil), the significance rate of elevation is reduced because these regions are plains and plateaus and lower in elevation than the other areas. Latitude has been found having a significant effect in the southwestern sections of the region (south of Azerbaijan-e-Gharbi, Kurdistan and Zanjan) and, in a more scattered manner, in the north of Urmia Lake and it seems that the reason for such a significance is the passing of the precipitation systems from the southern sections of the region.As in April, the effect of the elevation on the rainfall has been also found significant in all the sections of the region in May. The highest rate of significance has been found centered in the western and central sections of the region (particularly in the central parts) and this is completely due to the existence of the mountainous air masses. Considering the gradual displacement of the western winds towards the northernmost parts of the region and the vertical irradiation of the sunlight onto the sun-facing foothills, the role of the elevations becomes more accentuated in the creation of convectional rainfalls and the regions with lower elevation would receive lower precipitations. In June, as well, except the south-eastern section of the region (eastern half of Zanjan Province), the other regions have been found with the significant effect of elevation on the creation of rain. In this month, the conditions fit the occurrence of foothill convection in the studied area. The highest effect of the rising and falling lands on the creation of the rain has been evidenced for the north-western sections and this is in match with the path through which the western winds pass on these days; that is because the rain-causing winds are present in this section in this month and, considering the region’s elevations, cause the occurrence of rainfall. The effects of latitude in June is like those in May and the presence of the western winds and setting of the ground for the foothill convention causes rainfalls in the northern and central section of the study region.

Elevation has been found influential in the entire studied region on the rainfall because the high density of high grounds causes the ascension and condensation of the humid air that causes rainfall. Besides elevation, the dip also influences the rainfall in Kurdistan and south of Azerbaijan-e-Gharbi because the orientation of the foothills in this section sets the ground for the dynamic ascension of the humid air. In Ardabil and north of Azerbaijan-e-Sharghi, slope is also an effective factor. The high slope of these regions causes the acceleration of the humid air masses’ ascension. The effects of the latitude on rainfall during spring are different and mostly related to the presence of the western winds; in April in Kurdistan and in May and June in Azerbaijan-e-Sharghi, latitude has been found with the highest effect on the rainfall.

Soil erosion by water is one of the most important destructive factors on the earth's surface. The slope and aspect are the factors controlling the movement of water and sediments on the surface of the slopes and have a special contribution in different soil characteristics. In general, the public relations of surface erosion and soil loss are continuous, depending on the degree and length of the slope. As the degree and length of the slope increases, the discharge and flow rate increases, and the rate of separation and transfer of particles increases as well. This study was conducted to investigate the effects of slope and aspect on soil characteristics in slopes with weak vegetation cover in Western Zanjan semi-arid region, northwest Iran. Five plateaus were surveyed on both the northern and the southern slopes with different slope percentages (9-10, 13-17, 16-22, 29-31 and 33-37 percent). Soil samples were taken from two depths (0 to 5 and 5 to 15 cm) at four positions with a distance of two meters along the slope during two replications. Finally, 160 soil samples were considered for determination of particle size distribution, organic matter and lime size distribution. The results of this study showed that the surface erosion of the studied area was strongly affected by slope and aspect of the land. In the two-meter position from the top of the slope, there was the highest degree of fine particle erosion but at the bottom of the slope, the relative frequency of fine particles was increased. The surface erosion rate in the southern slopes was on average 23% higher than that of the northern slopes. Also, the results showed that increasing the slope had an incremental effect on the amount of sand and a significant reduction effect on clay content (P < 0.05, R2 = 0.43).

Importance of location factors substantially change the climatic phenomena and developments can be enjoyed. Influence of these factors can be strengthened, diluting and determine how the distribution of climatic processes be flashed as a result recognizing the role and relationships of these factors can lead to the understanding of the spatial patterns of climatic variables and the improvement of environmental planning. Accordingly, in the present study using monthly rainfall data of the synoptic station 121, climatology and rain Northwest of Iran in the period of assessment 1987 until 2014, and the use of the data, elevation, latitude, tilt and direction of tilt was trying features and relationships in spatial distribution and location factors of rainfall changes about the analysis. Therefore, the purpose of the center of the circle, half the average of the standard geographic change and even regression (GWR) was used. The results of the investigation showed that during the month of October due to the low amount of variance in the Western region, winds, rainfall, low spatial and spatial factors play an important role in the changes of precipitation. In November, while strengthening the system of precipitation in the region, the role of spatial factors in changes to rainfall reaches its peak in December, but due to the power systems of the proper moisture and nourishing rainfall, of the role of regional rainfall eased on location factors and changes in precipitation are more associated with atmospheric agents.

Changes in Climate parameters have been accelerated in the coming age, which can affect agricultural activities directly and indirectly. Temperature and precipitation are the most complex climatic factors. Spectral analysis is a scientific and efficient technique used to recognize and detect the hidden behaviors of these variables. In this research, in order to study and analyze the temperature and precipitation return periods using spectral analysis, the statistics of climate parameters (precipitation, mean, maximum and minimum temperature) for a period of 27 years (1989-2015) were used for the sustainable land management. For this purpose, the climatic data of temperature and precipitation entered the MATLAB software environment and Periodogram of each of the climatic parameters was drawn in a separate way. The results of each Periodogram study showed that the absolute minimum of temperature had significant cycles with the return periods of 3.8 and 2.4 years; the absolute maximum of temperature had a significant cycle with a return period of 2.1 years and the mean temperature was significant with a return period of 2.7 years. Also, the review of the Periodogram related to precipitation showed a significant cycle with a return period of 3.4 years. The Results from studying cycles indicated the existence of short-term return periods for climate variables in the region. Given this issue and the need to protect agricultural products, especially garden products, it should be done by applying water and soil resources management methods, including creating terraces and increasing soil roughness; Also, cultivation of appropriate plant species for the suitable regional climatic conditions, Drought resistant and low water requirement, the most optimal conditions could be created for the cultivation of horticultural and agricultural products.

In the vast majority parts of the Earth, a prospect now visible is the mostly synthetic thinking and fabrication by the human hand. Collision and impact of humans on the natural environment in the short and long-term courses for obvious geographical features have changed a variety of spaces. One of the consequences of human impact on the natural environment during the current period is the phenomenon of climate change. One of the climatic parameters that plays an important role in agriculture, energy, urban, tourism and road transport is the minimum temperature. In this study, an attempt was made using the minimum temperature data from 5 meteorological stations in the West Mazandaran province, as well as HADCM3 model data, to show how to change this parameter in the future periods based on simulation by the SDSM model. Accordingly, after selection of the suitable climate variables and model calibration, the accuracy of the created model in the base period was evaluated; after ensuring the sufficient accuracy of the model according to A2 and B2 scenario, data minimum temperature in 2100 was simulated. Based on the simulation results showed that the values of minimum temperature in the region over the coming years would increase. This parameter was such that the average seasonal periods 2016 to 2039, 2040 to 2069 and 2070 to 2099, as compared to the baseline period would increase, on average, by 1.8, 3.5 and 6 percent. The largest increases in the minimum temperature in the western and southern parts of the region could occur. It was also found that unlike other months of the year, the minimum temperature in January would be a decreasing trend.

One of the major issues in the contemporary world is climate change. The behavior and characteristics of parameters affecting climate change can cause them to be seen and hidden. As one of the effective ways to detect overt and covert behaviors for periodic climatic data series, Spectral analysis can be used. It is the analysis of each of the wavelengths series, making this behavior clear. Accordingly, the present study was an attempt to use the method of spectral analysis, data cycles in the minimum temperature, maximum temperature and precipitation in Ramsar station (located in the western regions of Mazandaran province) an nd Babolsar (located in the central parts of this province) in a period from1961 to 2014. For this purpose, temperature and precipitation data were obtained from these stations; MATLAB software environment and the environment for the software were logged for each of the variable in the stations. The results revealed that the minimum temperature at both stations had significant cycles, with the return period being 2 to 5 years; Remote Link could be fit into the cycle parameters such as NAO, AO and ENSO. Analysis of the period gram showed cycles 8 and 5/13-year-old and 5-year-old period in Ramsar and Babolsar. During the rainy cycles, the difference between the two stations and the difference in the geographical position affected systems, and rain accounted for the difference in speed dual-zone climate indicator for Remote Link.

Pervasive cold days are one of the abnormal continental events that have a lot of effects on environment and human activity. These events are created as a result of formation of complex atmospheric patterns. In these patterns, knowledge of how these atmospheric systems interact can be very useful in prediction of the similar conditions and reduction the contingency damages. On this basis in this present research, it has been tried to analyze the earth's temperature conditions and dynamic and synoptic conditions of different levels of atmosphere on 21 January 1964 as pervasive cold day in Iran by using data from minimum temperature gained in different parts of the country and also the atmospheric data from 1960 to 2010. In this day 98.4 % of the area has been affected by the cold. The results of synoptic and dynamic analysis of atmospheric systems that creating the cold of this day showed that created a blocking system in west and center of Europe and establishment a low height system in north of Russia and the opposite movements of these two systems to each other has caused that cold polar air from northern Scandinavia have moved to Iran. It has also been recognized that height factor has performed an important role in cold extremity in this day across the country.

1. One of the special temperature states in which extreme amounts of minimum temperature are observed, is the cold wave. The extreme cold waves due to the severity and sudden occurrence have an important impact on the ecosystems and human societies. There is a probability of occurrence of cold waves throughout the year and in each season, it creates its own special problems and damages. Because of the low angle of sunshine and the cold weather, these waves are stronger in winter and threaten the life of all living creatures.
They also play a decisive role in economic, environmental and developmental issues such
as road construction, damping and bridge construction, and can cause damage in various
sectors. The intensity and weakness of the cold waves depend on the complex synoptic
and dynamics factors, some of which are less well-known and their analysis using a
synoptic method can identify features such as the source, track, intensity and frequency
of pressure systems and helps to recognize the fundamental factors and their characteristics and to increase our understanding of winter cold waves.
2. Material and The study area in this research includes the whole country of Iran. Iran is a rugged country with an elevation average of about 1250 meters. roughness plays an important role in Iran's temperature; therefore, the temperature decreases wherever height increases. Iran’s average maximum temperature is 18 degrees Celsius and the average minimum temperature is 11 degrees Celsius.
In the present study, the effective patterns in creating winter cold waves in Iran were
identified using environmental to circulation approach. In order to achieve the specified
purpose in this study, two environmental and atmospheric databases were used.
Environmental data included the minimum temperature in winter between 1960 and 2011.
In this research, it has been attempted to be defined the cold Somehow so that the principle of its relativity is considered in different regions; accordingly and according to Alijani and Hooshyar (2008) and Massoudian (2013) researches, Two conditions for the
identification of cold waves were defined in the country. On the basis of the first
condition, days were considered as a day with a cold wave that standard Z score for the 10th percentile of minimum temperature data is less than or equal to -1/2. By defining
this condition, only very low temperatures were taken into consideration for each of the
7187 cells studied and the concept of relative coldness was considered for different
regions of the country. The second condition is the continuity of the cold weather for at
least 3 days; based on this condition, the systemic coldness from the local coldness (which
is caused by environmental factors or overnight cooling) is separated. According to these
conditions, cold days were identified on the ground and related synoptic systems were
investigated in different layers of the atmosphere.
3. In the first pattern, about 45 percent of the country's surface was affected by the cold
wave, and the average minimum temperature was -4.4 Celsius degrees. Based on surface
temperature maps in the northwestern part of the country, temperatures below -20 ° C
was observed. The main factor behind the formation of this pattern is the Azores high
pressure system, which has led to cold weather penetration from northern Europe to Iran.
Due to the formation of the second pattern, about 21 percent of the Iran’s surface was
affected by the cold wave. The average minimum temperature in the country is -2.9
Celsius degrees, which was the highest among other patterns. The lowest temperatures in this pattern were between -14 and -18 Celsius degrees that observed in the northwest, the central parts of the Alborz and northeast of the country.
In the third pattern, the daily average of minimum temperature is -2.5 Celsius degrees,
which is the lowest at the different patterns. In this pattern, 50 percent of the countrys
surface was affected by the cold wave. In this pattern, cold weather penetrates the
southern parts of the country and its impact was observed in many parts of the country.
On the day the representative, the Siberian high-pressure system is located at high
latitudes and in the central parts of Russia. The weakening of the Iceland low-pressure
and the displacement Azores high-pressure towards the westerner parts, has strengthened the Siberian high-pressure and increased its impact.
The minimum temperature average in the fourth pattern was -3.5 Celsius degrees and the cold air coverage in the country was 30 percent. Lowest temperature values were
observed in northern parts of the provinces of East Azerbaijan and Ardabil. This pattern
is somewhat similar to the first pattern, but contrary to the first pattern, there is a negative pressure anomaly in the northern regions of Europe and throughout Russia. The Siberian high pressure has shifted to the east and the European high pressure is located throughout the region, while in the first pattern, this high pressure was located in Western Europe.
The minimum temperature average in the Fifth pattern was -3.4 Celsius degrees and the
cold weather coverage in the country was 36 percent. In this pattern, the core of the
Siberian high-pressure is located in west of Mongolia, and the Icelandic low-pressure was
eastward movement and located in Scandinavia. This system has been located in large
parts of northern Europe and central Russia as well as parts of the Atlantic in Western
Europe. The expansion of this system and its displacement have caused more impact on
Siberian high-pressure.
4. Performing synoptic analyzes on atmospheric patterns showed that all the pervasive cold
waves in Iran were caused by the formation of massive high-pressure patterns in the
country, parts of the Middle East and Asia and South-East Europe. The position of the
two Siberian and Azores high-pressure systems has played a very important role in the
transfer of cold air to the northern latitudes towards the country. The deployment of a
polar low-pressure system in northern parts of Europe and Russia has led to the influx of
cold air towards the southern regions. The formation of specific patterns of the
intermediate layers of the atmosphere has had a significant effect on the creation and
intensification of the winter cold waves. So that the extreme winter cold waves are formed when Blocking systems have been established in Eastern Europe and their eastern Trough has been located on Iran.