جستجوی مقالات مرتبط با کلیدواژه « chaos theory » در نشریات گروه « جغرافیا »

Recently, issues raised by changes in precipitation, especially problems brought about by floods and droughts, along with the environmental effects of diminished rainfall, have underscored the importance of precipitation studies at different temporal and spatial scales. Due to the pervasive impact of precipitation parameter in various urban, industrial and agricultural fields with respect to water supply, the identification of fluctuations, changes and precipitation structure is of particular importance, especially in arid and semi-arid regions. The similarity feature in climatic variables allows the use of fractal geometry and analysis of temporal and spatial changes. Accordingly, the use of fractal geometry in predicting the behavior of many natural processes, including precipitation in different regions, has a special place. The goal of this study is to investigate the structure of different time periods of precipitation in Shiraz synoptic stations to explore changes and determine the spatial position of precipitation in the stability and instability period.

In this study, daily precipitation data was received over a period of 58 years (1956-2013) from the Meteorological Organization of Fars Province to investigate the structure governing precipitation parameter. Then, statistical deficiencies were corrected by restructuring using difference ratio and linear regression. The methodology and algebraic logic of calculations in this study are such that in the first step, research parameters are arranged from minimum to maximum in an ascending order. Then, based on the triangular threshold coordinates(2Π), the minimum and maximum were extracted based on linear structures of the desired criteria and algebraic mathematical reference was conducted using Relation (1). Relation (1)  F (x) =    Then, in order to apply the fractal structure by applying the criterion for mathematical reference using Relation (2), the real structure of the desired meteorological parameters was obtained. Relation (2) Y = m2 × sin (1/m)   Finally, by overlapping the output charts of the actual structures and the classical structure of the fractal (Figure 2) in the algebraic ranges of -0.4 to +0.4, the algebraic process of each climatic parameter was evaluated separately.  

In this study, based on the results, in addition to the daily analysis of the governing structure of precipitation over a 58-year period (1956-2012), which covered 21185 days, the governing structure along with the analysis of equilibrium dynamics of structures and its functions in three time periods (three 20-year periods) of different daily precipitation were also examined separately. The first period began in January 1, 1956 and lasted for 7065 days. The relevant calculations were performed on the data derived from the first period, which based on the findings of this study, precipitation in Shiraz''s synoptic stations do not follow the fractal logic in the first period by applying fractal algebraic structures, Also, in the second period, similar to the first one, the precipitation structure does not comply with a particular fractal logic. In other words, the logic governing precipitation parameter during the first and second periods changes from equilibrium to non-equilibrium. However, unlike the previous two periods, the fractal logic is followed in the third period.

The self-similarity feature in climatic variables allows the use of fractal dimension and analysis of temporal and spatial changes. Accordingly, the use of fractal geometry in predicting the behavior of many natural processes, including precipitation in different regions, has a special place. The goal of this study was to investigate the structure of different periods of precipitation in Shiraz synoptic station to identify changes and determine the spatial position of precipitation structure in the period of stability and instability. The behavior of meteorological parameters in various parts of the world is a function that never follows uniform algebraic structure. Therefore, the analysis of complex systems and changes in nonlinear climate parameters using chaotic, fractal and fuzzy concepts offers a suitable way to understand the equilibrium state and dynamic analyses of climate fractal changes. The results indicate the dynamic transition of this time period from non-equilibrium to equilibrium. Therefore, according to the three time periods, the equilibrium dynamics of the daily precipitation structure approaches fractal structure.

Phenomenologists believe that in nature there is a dual structure that depends on each other intrinsically, one is a structure that is objectively visible to any observer, and second the complex and interconnected structures that are not exposed to tangible objectivity. Geomorphology, based on the phenomenological view, also tries to understand non-tangible structures.Damavand Peak is a Quaternary volcanic phenomenon with an altitude of 5671 meters in the middle of Alborz sedimentary ridge. This phenomenon has changed the overall structure of the region and imposed certain changes on the whole Alborz region. Damavand has a different structure compared to other volcanoes, such as Sahand, Bazman and Kilimanjaro, and does not follow the radial form. It has the shape of the Owl's Eye . The main goal in this paper, is to clear the effects of structure on the behavior of the Haraz River and emphasize to spatial memory, energy distribution pattern and the changes of river flow.

The variables used in this research are mostly those of defining the structural pattern of the region. These variables are classified into three groups, linear, point and superficial, often defining-geometric patterns are considered in geomorphology. The variables analyzed here are i) the linear variables comprising fault lines, drainage networks, ii) the surface variables including the erosional surfaces along the Hazard River and iii) the points variables constituting the villages and peaks. All analyzes are based on satellite images and 30-meter DEM of Iran and the accuracy of these analyzes has been checked with field visiting (15 times). All of these information is presented in the framework of the phenomenological method, relying on the chaos theory, and the concepts of behavior geomorphology.
Discussion and

The special structure of Damavand and its activity, have been reflected on structure of region, behavior of Haraz River, capture river, and defined a new space identity.How Damavand has changed the structure of region .A: Changes in the fault systemsGenerally, structural patterns in the Alborz region have been influenced by fault activity. Damavand volcano as a new plutonic activity has changed the tectonic structure and plays a decisive role in structure of this region. Comparing the tectonic structure of region (without volcano's activity) with the current structure (after volcano's activity) revealed the new structure created by Damavand is considered as a turbulence in the general structure.B: Expand area of Haraz River basin.As shown in figure (3), there are three fault systems in the area. By evaluating and measuring the northern fault systems, the length of all this fault was 15 to 45 km, except that of Haraz with length reaching to 104 Km . This indicates that Damavand's activities have caused such a change in the area of draining basin.In other words, the Haraz River basin was much smaller, and after the volcanic activity its basin has increased sharply and all branches of the river that have already flown south (Tehran) have been redirected to the north.C: change the pattern of draining system.Investigating the drainage network in the area shows that the structure of the drainage network in Damavand has different patterns with other adjoining areas. As you can see, there are two distinct patterns in this area, one dendritic pattern and another spiral pattern . Changing draining patterns with Damavand volcanic activity is routine, but the Damavan rotational form is a special feature that separates it from other volcanoes such as Kilimanjaro, Bazman and Sahand. Because almost all of them have a radial form and Damavand has a structure Owl's eye model with a clockwise movement. This form has caused many processes to change and has had important effects on the distribution of energy and matter, especially in the Haraz River.D: How Damavand have changed behavior of Haraz River.The sediments of these lakes now are at higher elevation than the current level of rivers in the areas of Nandel, Baijan, Gazeneh, Lasem and Lar. The excavation started in the Lagos valley from mid-December 2017, confirming the depth of sediment, more than 100 meters, and this indicating the depth of the lakes. This process has made the river function as a continuous and normal flow is converted into a cascade stream.E: change the space identity.After overflow and breaking the lakes, along the banks of the rivers, sedimentary beds have been leftover and created numerous villages on them. This phenomenon in Iran means the change of space identity, because in the mountains of Iran, villages take their space identity from the Water-Ice Equilibrium line (WIEL).

If we call geomorphology as a knowledge of land forms and analysis of patterns, we can claim that the Damavand volcano is different from the other volcanoes like Kilimanjaro, Sahand, Sabalan, and Bazman, and this difference is related to its chaotic structure. Damavand volcano have been affected on the environmental processes, such as the distribution of energy, matter and Haraz river behavior, and the main aim of this paper is to explain this. Although the patterns of the formal structure in Albourz Mountain are more influenced by the faults, the structure of the Damavand formative have completely confused the tectonic structures and changed the rule of formative system and behavior of Haraz River. The influence of structure in a variety of dimensions, such as the distribution of energy and matter on the region, river capture and river behavior, river basin expanding and sequences sediment has been able to create general space identity of this region. This article is the result of a studying in sabbatical leave at the University of Wurzburg based on the principles of phenomenology and the results is obtained show that:*The Damavand form has followed the structure of the Owl's eye model and created a land-cyclone. *Damavand has changed the patterns of distribution of energy and matter in this region, created a river capture and expanded the Haraz river network.
*The structure of the owl's eye of Damavand Has been created a special space identity in this region.

Physical texture of urban areas can have chaotic behavior due to their non-linear and unpredictable characteristics. The theory of chaos in urban development attempts to explore physical development which has fractal geometry, as a non-linear, sensitive to preliminary conditions and generalizable to different scales with an emphasis on geometric aspects of it. In this study, with the aim of achieving the physical growth pattern, the physical status of a part of Mashhad urban complex has been investigated and analyzed as a coherent whole with homogeneous function (tourism).

The research method in this study is analytical-descriptive. In order to achieve the goals of the research, the urban fabric of a designated area has been studied with the help of up-to-date maps and specialized software. Scaling has been adhered to as a generalizable process, In the process, Therefore, this research is one of the applied research.

 With respect to scaling, the correlation coefficient between the geometric parameters indicates a significant relationship between these parameters. The fractal spectrum of the study area at various scales (whole and component) indicates the autopsy of the study body and describes its process.

As a result, physical growth process in the studied area is chaotic and it follows a specific growth pattern at different scales. Far from the populated cores (Mashhad, Toos, Torghabeh and Shandiz),physical  geometry tends to be linear, and it is also in relation to transport arteries' geometry.

this era, as the age of knowledge and information, features features such as increasing competition and complexity. Therefore, in such a situation, the attributes, skills and tasks of leaders should be different than the traditional type. nowadays, complexity and chaos theories have created a good field for research and research in different fields. The paradigm that focuses on empowerment of the adaptive capacity, creativity and learning of complex adaptive systems in the context of knowledge producing organizations. Hence, it is necessary for organizations to adapt directly or indirectly, to preserve their lives, by changes of day. in this paper, we try to investigate the theory of complexity of leadership, chaos theory and organization itself, innovation and creativity in organizations as well as application of these concepts. Complexity and two subset of that is the chaos of the changes generated in human knowledge and changing the nature of the work environment. In the changing conditions today, chaotic systems act as living organisms and have to be creative and innovative in order to reach their environment, thus organizations can be developed with empowerment, creativity, self - organization and without a central management.

  One of the main issues in hydrology and water resources is investigation of river flow. Due to innovations and capabilities of the chaos theory, nowadays, chaos analyses are used to analyze river-flow time series. Since investigation of the presence of different characteristics at different time scales in rivers is one of the main challenges of hydrology in recent years, the aim of this paper is to study the behavior of river flow at different time scales. The behavior of river discharge can be studied precisely by applying nonlinear and chaotic analyses. The chaos theory, as the foundation of nonlinear dynamic systems has created great changes in understanding and expressing the mode of different phenomena in recent decades. This theory deals with the study of systems that at first glance may seem irregular; but in fact they are governed by clear rules. Such systems are very sensitive to primary conditions, so that seemingly minor inputs could have a significant impact on that. Such systems are called chaotic. With regard to recent studies, based on chaos theory for flow discharges, the chaotic or random nature of a system could be identified by using some discriminative indices. Despite chaotic studies conducted on the river discharges, chaotic analysis of flow discharge in Karun River has not been implemented for different time scales. In this study, the presence of chaos at daily, monthly and seasonal scales in discharge data of Karun River, Mollasani station, is discussed. Mollasani station is located downstream Ghir barrage (where, Dez, Gargar and Shotait River join together) and upstream Mollasani city. Daily, monthly and seasonal flow discharge data in Mollasani station (1967 to 2011) are used. Four nonlinear dynamic methods were used: 1) phase space reconstruction, 2) correlation dimension method, 3) largest Lyapunov exponent, and 4) spectral power. The state (phase) space is a useful tool for studying dynamic systems. According to this concept, a dynamic system can be described by means of a state space diagram. Each dynamic system consists of differential equations with partial derivatives. To determine these equations and their type, the embedding dimension and time delay parameter must be determined. The delay time could be obtained from the method of assessment of correlation function (ACF) or average mutual information (AMI). In this study, the average mutual information is used to estimate delay time of the dynamic system. In this method, time of first minimum occurrence in the average mutual information function is selected as the appropriate delay time. The embedding dimension is obtained from the false nearest neighbor (FNN) method. This algorithm provided information concerning optimal embedding dimension for the dynamic system. The results showed that the daily times for daily, monthly and seasonal data are 97, 2 and 1, respectively, and the optimal embedding dimensions are 9, 6 and 2, respectively. To determine chaotic nature of the system, correlation coefficient was calculated. The correlation dimension at the monthly scales, due to saturation of the diagram, is obtained as 2.704. Therefore, Karun River system is chaotic at this scale. But at the daily and seasonal scales, the diagram's trend was ascending and as a result, the river discharge is random. Another indicative criterion of the chaotic system is the largest Lyapunov exponent. The behavior could be measured in each dimension by using the Lyapunov exponent. Presence of positive Lyapunov exponent is an important indicator of the chaotic system. In this study, elongation factors and largest Lyapunov exponent are calculated on the basis of Rosenstein's method. Taking the value of optimal embedding dimension as m, the value of this exponent can be calculated. In the absence of the optimal embedding dimension, this parameter is predicted based on different m values. At monthly tile scale, the largest Lyapunov exponent was positive (0.0093). The extent of band width at monthly scale is another proof of chaotic nature of this river's discharge. The chaotic nature of the discharge data can also be calculated by power range. These methods can estimate the chaotic or non-chaotic behavior and cannot estimate the complexity of data. At daily and seasonal scales, according to correlation dimension, the river discharge is random (non-chaotic). But, flow is chaotic at the monthly scale. It seems that the geographical location of Mollasani station may affect the chaotic or randomness of Karun River's discharge

Because of the great friability of ecologic-social systems in desert regions, planning for tourism development and use of its capabilities for rural development need an explanation of rural tourism systems. Mesr village is one of the most important rural tourist regions in Khur-biabank county that, in recent years, has experienced tourism activities development and its changes. This paper aims to recognize a tourism system development model in the village and explain it by approaches and theories related to the development of tourist destinations. For this purpose, qualitative data are prepared through interviews, conversations and surveying observations as well as using theoretical foundations, effective variables, processes and structures in the rural tourism system of Mesr village. After the system is recognized, a model is presented to explain the tourism system development processes. The results of the model show that effective introduction of tourism in the region attracts more visitors, for which the important role of entrepreneurs should be stressed. This role can be played in increasing the number of tourists in an organized manner, increasing the local participation, reduction of migration and so on. In another part of the study, the conformity degree of the model is enquired with chaos and tourism life cycle theories. The system being compatible with and based on the tourism life cycle theory, Mesr is found to be in a satisfactory development stage. Also, it appears that the creative destruction in the chaos theory is compatible with the satisfaction and development stage in the tourism life cycle theory.