Mahmoud Khosravi
Volume 9, Issue 34 , August 2000, , Pages 56-64
Abstract
Tourism industry is considered as one of the most important activities in the contemporary world. Every year there are 1.7 billion tourist travels which cost about $600 billion. The incomes of some countries such as Tunisia and Bahama are provided by tourism industry. Unfortunately, Iran’s share ...
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Tourism industry is considered as one of the most important activities in the contemporary world. Every year there are 1.7 billion tourist travels which cost about $600 billion. The incomes of some countries such as Tunisia and Bahama are provided by tourism industry. Unfortunately, Iran’s share of this industry is less than $200 million. On the whole, there is no doubt that climate is the main cause of the seasonal characteristic of tourism. In this paper, after examining major points and analysis of some models of tourist regions’ assessment, epistemological limitations of tourism studies are discussed. One of the most difficult stages is modeling the future climate. Assessment of the effect of climate on tourism is a sensitive and multi-faceted task. Considering the need for evidential research, we face many questions that need to be answered. Our main goal in this paper is to provide such answers. Today, there are evidences that in activities regarding the effect of climate, the mutual effects of environment and human are also considered. Therefore, the present article has also discussed the possibilities and limitations of research concerning climate effects on tourism. In this paper, first the importance of tourism-climate issues are discussed, and then a comprehensive examination of epistemological matters concerning climate effect research has been presented; finally, strategies for more advanced research about climate effects on tourism have been proposed.
Mohammad Hasan Ganjii
Volume 1, Issue 4 , May 1992, , Pages 56-60
Abstract
In the third issue of Sepehr, we presented a discussion about the shape of the Earth and its hypothetical divisions (orbits and meridians), and the importance of each one. Before we go into the discussion of the movements of the Earth, it will not be out of place if we first obtain brief information ...
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In the third issue of Sepehr, we presented a discussion about the shape of the Earth and its hypothetical divisions (orbits and meridians), and the importance of each one. Before we go into the discussion of the movements of the Earth, it will not be out of place if we first obtain brief information about the Earth in space, as understanding of many geographic concepts will relate to this information.
For centuries, man thought that Earth was the center of the universe, but today's man has gained amazing information about the universe. It is now assumed that our Earth is a small planet that moves along eight other planets around the Sun, and the Sun is a star that moves with thousands of other stars in a galaxy among millions of galaxies in an infinite universe.
Shokrallah Mohammadi
Volume 8, Issue 30 , August 1999, , Pages 57-58
Abstract
Today, with advances and development of computer technology, many firms and organizations which practice map preparation have turned to conversion of manual system (manual cartography) to computer system (digital cartography). Currently all stages of manual cartography are carried out using computers, ...
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Today, with advances and development of computer technology, many firms and organizations which practice map preparation have turned to conversion of manual system (manual cartography) to computer system (digital cartography). Currently all stages of manual cartography are carried out using computers, which leads to increase of the speed of cartographic operation, achievement of top quality at stages of work and reduction of map preparation costs.In this paper, the Raster and Vector information in creation of cartographic images as well as advantages and disadvantages of these images and their method of processing are examined.
Fereshteh Tavakkoli
Volume 12, Issue 45 , May 2003, , Pages 58-61
Abstract
The purpose of geological studies is to identify water-containing layers and basin reservoirs, as well as to determine the tectonic and geological structure of the area. In general, the Aligudarz plain and its southern highlands are located at the site of the major geological structural unit of Iran, ...
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The purpose of geological studies is to identify water-containing layers and basin reservoirs, as well as to determine the tectonic and geological structure of the area. In general, the Aligudarz plain and its southern highlands are located at the site of the major geological structural unit of Iran, so that it is bounded on the north to Sanandaj and Sirjan and on the southwest to Oshtorankooh, which is part of the High Zagros. Considering the geologically and structurally special location of the site, two examples are briefly described.
Hasan Shamsi
Volume 1, Issue 1 , May 1990, , Pages 58-64
Abstract
During the Second World War, radar was used to detect objects or targets and to determine their distance and direction (or azimuth).
The radar performs its task by sending extremely short waves (called microwaves) to a target and their return from the target to the sender. The total traveling time ...
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During the Second World War, radar was used to detect objects or targets and to determine their distance and direction (or azimuth).
The radar performs its task by sending extremely short waves (called microwaves) to a target and their return from the target to the sender. The total traveling time of these waves, shown on their indicator, determines the distance between the sender and the target.
After World War II, especially in recent decades, designers and makers of surveying and geodetic instruments such as Wild, Kern, Zeiss, AGA, So-kisha, and American K.6 have recognized the use and application of electromagnetic waves in surveying and geodesy, and began to develop electronic and electro-optical space measurers as well as tellurometers. In the first paper from this series of articles, we introduce electromagnetic and radio waves.
Bahman Ramezani Gourabi
Volume 20, Issue 78 , August 2011, , Pages 59-65
Abstract
Marginal areas and islands of the Persian Gulf are located in a warm and humid climate with high absolute humidity; areas with an unfavorable climate among whose characteristics are minimum precipitation and water shortage, abundant water vapor, low relative humidity, high radiation levels , Dust, … ...
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Marginal areas and islands of the Persian Gulf are located in a warm and humid climate with high absolute humidity; areas with an unfavorable climate among whose characteristics are minimum precipitation and water shortage, abundant water vapor, low relative humidity, high radiation levels , Dust, … , which, considering urban development plans and the creation of new towns and industrial areas associated with increase in population, are of great importance in terms of energy costs in an unfavorable climate. In the past, indigenous people provided more or less tolerable conditions due to the presence of Hara forest vegetation and the use of indigenous techniques against undesirable climate. However, due to new structural changes, this approach is accompanied by the Increasing cost of energy over the year. The purpose of this paper is to identify the potential of creating desirable climatic conditions in Hara forests in the Persian Gulf, with an emphasis on reducing energy costs. The method of research is descriptive-analytical, using existing statistics of meteorology and application of bioclimatic human models. This article tries to introduce the development and understanding of these forests as one of the ways to create the optimal local and regional climate in the Persian Gulf region for the desirable human development, so that vegetation is preserved in the UAE in the southern region of Persian Gulf with great costs, while in the northern regions of the Persian Gulf (Iranian section), this potential can be developed at the lowest cost in the margins and islands, in which terms it is incomparable with the south.
Mohammad Reza Zand Moghaddam
Volume 13, Issue 52 , February 2004, , Pages 59-60
Abstract
“Geography is the science of places”, “Geography is the science of connections”, “Geography is the science of human ecology”, “Geography is the science of dispersion”, and “Geography is the science of mutual relations”... are all the beautiful ...
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“Geography is the science of places”, “Geography is the science of connections”, “Geography is the science of human ecology”, “Geography is the science of dispersion”, and “Geography is the science of mutual relations”... are all the beautiful definitions of geography that have been expressed by the great scientists of this science, such as Vidal de La Blache, Griffith Taylor, etc. Each of the above definitions, while in the simplest form of expression, has certain complexities, which, after stating causes of various factors, has established the foundations of geography, and has been interpreted by geographic associations all over the world, and has been the founder of many thoughts and ideas that made a significant contribution to the advancement of geography in the world, so that in addition to the advancement of this beautiful human knowledge, it caused certain followers each explain the old ways and try to contribute to the progress of thoughts through critique and evaluation. However, from another perspective, the abovementioned scholars were not only the founders of a new tradition, but also helped their followers in their respective countries and in other countries to benefit from it and promote their thoughts, especially in their country, and this fact has been developing the science of geography in these countries and providing the ground for scientific advancement and other aspects of domination over the world both scientifically and colonially. In this paper, we try to recognize our share in geography and to know what geographic dominant ideas exist in our country? Or, with what point of view, a better and more appropriate thought can be chosen for the geography of Iran. With a brief look at geography in Iran, we will find that this science, along with the progress of other sciences in the world of Islam, was properly cultivated during this period, and the scholars of the Balkh and Iraqi schools, each with their own interpretations, made significant contributions to the flourishing of this era, even by writing the geography through pilgrimage literature.
Mohmmad Javad Dadrast
Volume 9, Issue 35 , November 2000, , Pages 59-64
Abstract
The need for robust and advanced support of information processing in planning (due to the volume of data and the growth of number of users) makes efficient and powerful systems of information processing inevitable. GIS, or Geographic Information System, with the special feature of combining spatial ...
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The need for robust and advanced support of information processing in planning (due to the volume of data and the growth of number of users) makes efficient and powerful systems of information processing inevitable. GIS, or Geographic Information System, with the special feature of combining spatial and non-spatial data, has gained a special status among managers and planners.
Ramin Kiamehr
Volume 15, Issue 58 , August 2006, , Pages 60-64
Abstract
Since 1986 several gravimetric geoid models were published in the Iran region. Based on primary investigation on these gravimetric geoid models, it is found that their relative and absolute accuracies versus GPS/levelling are more or less the same or in some cases worse than the current available global ...
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Since 1986 several gravimetric geoid models were published in the Iran region. Based on primary investigation on these gravimetric geoid models, it is found that their relative and absolute accuracies versus GPS/levelling are more or less the same or in some cases worse than the current available global geopotential models (Kiamehr 1997,2003 ,2001a , 2003b, 2004 and Kiamehr and Sjöberg 2004). Regardless the effect of choosing proper computational method in determination of any geoid models, the quantity and quality of the gravity anomaly database plays a major rule in the final result of them. The main aim of this research is the creation of a more complete and also refined new gravity database for Iran. For this purpose different dataset from different sources are gathered and combined in a single database. Then we start to refine it from possible outliers by using Least Squares Collocation (LSC) approach. A special method used for the interpolation scheme of free-air gravity anomalies in order to take into account the effect of topography. The final grid file was creates based on the Kriging method with 80" * 90" resolution. The overall accuracy for the current database is estimated to near 10 mGal.
Reza Arab Sahebi
Volume 14, Issue 55 , November 2005, , Pages 60-64
Abstract
Geodesy is a science that is related to determining the shape and geometry of the Earth and coordinates of points on the surface of, and above, the Earth, such as satellites and other moving objects above the Earth's surface. Therefore, in order to meet the geodesic goals in regards to positioning, we ...
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Geodesy is a science that is related to determining the shape and geometry of the Earth and coordinates of points on the surface of, and above, the Earth, such as satellites and other moving objects above the Earth's surface. Therefore, in order to meet the geodesic goals in regards to positioning, we first need to define the geodesic-related coordinate system. In order to be able to objectify a point in three-dimensional space and to express its relation to a reference system called the coordinate system, we need to specify three parameters: 1 - origin 2 - axis directions 3 - parameters defining the position of a point in the coordinates system. One of the systems used in geodesy is the geocentric coordinate system, the origin of which is a point near the center of the Earth and the Z axis of the system is along the Earth's axis of rotation. Since the Earth's rotation is around the pole and the location of the pole is variable, the Z axis will have a different position, therefore we find it difficult to find the parameters determining a certain position in this system (factor III of the definition of the coordinate system). In this paper, using observations regarding the x, y components of the pole from 1962 to 1997, it can be concluded that this non-periodic motion can be studied and even predicted by using mathematical methods through the fitting of continuous functions. The results show that the power of showing this important movement in various mathematical functions is different, so that in some mathematical functions, the polar motion has an incremental acceleration, while others show that this movement has a completely irregular acceleration.
Alireza Azmudeh Ardalaan (Translation)
Volume 1, Issue 2 , February 1990, , Pages 60-62
Abstract
As the accuracy of observed angles and lengths is one of the main factors in the final accuracy of a mapping task, the justification of network also plays a major role here. The justification of network according to the real north is a simple task and has many advantages. If this operation (network justification) ...
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As the accuracy of observed angles and lengths is one of the main factors in the final accuracy of a mapping task, the justification of network also plays a major role here. The justification of network according to the real north is a simple task and has many advantages. If this operation (network justification) is performed through astronomical observations, the mapper must be aware of all sources of error in the justification of network and understand that even if the lengths and angles are accurately measured, the existence of error in justification of network can reduce the final accuracy. In this paper, that source of error is discussed which has not yet received the attention it deserves, and a field approach has been proposed to eliminate this error.
Mohammad Ekhbari; Abolfazl Ranjbar; Seyyed Mohammad Bagher Fatemi
Volume 15, Issue 59 , November 2006, , Pages 61-64
Abstract
Data extraction from satellite images has significantly developed in recent decades, and various algorithms have been introduced to extract information from satellite imagery, each of which has advantages and disadvantages. In general, the methods of classification of satellite images fall into ...
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Data extraction from satellite images has significantly developed in recent decades, and various algorithms have been introduced to extract information from satellite imagery, each of which has advantages and disadvantages. In general, the methods of classification of satellite images fall into two types of supervised and unsupervised classifications. Furthermore, supervised classification methods are divided into two parametric and non-parametric methods. In this paper, the purpose is to introduce and study the algorithms of parametric supervised and unsupervised classifications of satellite images in terms of accuracy and method of extracting information. Finally, by comparing the algorithms of the existing methods, we conclude that the method of maximal similarity is more accurate than the minimum distance and parallelepiped methods, but it is still not possible to achieve the desirable precision in classification using this method. In fact, statistical methods such as maximal similarity can not be used if the goal is acquiring high precision, because the method of maximal similarity is a completely statistical method, and therefore, it can not provide the ability to accept and use external information in a non-statistical form such as geometry of imaging, geometry of features whose images are being taken, as well as effective factors such as the atmosphere in the classification process, and this is one of the weaknesses of maximal similarity classification in comparison to model-based methods. Therefore, methods such as model-based and science-based have been introduced to improve this method and eliminate its problems.
Zohreh Merianji; Reza Borhani
Volume 12, Issue 47 , November 2003, , Pages 61-64
Abstract
Climate change is a general term that describes climatic discontinuity and rupture. In order to study temperature changes in Hamadan, temperature fluctuations in a statistical period of fifty years (1952-2002) have been investigated. According to a survey conducted in 1973, a sudden drop in the minimum, ...
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Climate change is a general term that describes climatic discontinuity and rupture. In order to study temperature changes in Hamadan, temperature fluctuations in a statistical period of fifty years (1952-2002) have been investigated. According to a survey conducted in 1973, a sudden drop in the minimum, and a sudden rise in the maximum, temperature were observed. According to the Mann Kendall test, there are significant changes in the three parameters of minimum, maximum and average temperature, including the decreasing trend observed in 1962, and this negative trend continued until 1992, and this year thereafter, an increasing trend of temperature can be observed. It should be noted that the maximum spring temperature is an exception, since in the year 1992 it is the beginning of cooling season. On the minimum temperature chart, the falling trend starts from 1957 and continues until 1974. The result is that the year 1992 is the beginning of a period of increasing temperature and climate change in Hamedan, and the temperature rise is 0.55 degrees averagely, 0.79 ° C at minimum temperature and 0.3 ° C at maximum temperature.
Volume 16, Issue 61 , May 2007, , Pages 61-62
Abstract
Introducing the book " Thermal remote sensing and its application in geosciences".
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Introducing the book " Thermal remote sensing and its application in geosciences".
Majid Mokhtarani
Volume 12, Issue 48 , February 2003, , Pages 62-64
Abstract
The system in discussion is a new tool and capability on the SPOTS satellite sensor, which we were eagerly waiting for. SPOT IMAGE and its partners have gained very good resultsout of this key innovation for customers of Digital Elevation Models (DEM) and geometrically corrected images with appropriate ...
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The system in discussion is a new tool and capability on the SPOTS satellite sensor, which we were eagerly waiting for. SPOT IMAGE and its partners have gained very good resultsout of this key innovation for customers of Digital Elevation Models (DEM) and geometrically corrected images with appropriate precision. On the SPOTS satellite a system called High Resolution Stereoscopic (HRS) was designed over a period of five years for creation of a Digital Elevation Model (DEM) for a coverage of 30 to 50 million square meters (one-third of the earth’s drylands).HRS is able to provide almost simultaneous topographic (stereo) images from very large areas.Its coverage is 120x600 km at every passage of satellite. This sensor will provide 126,000 square kilometers of coverage stereo images in just one day.This remarkable ability to provide stereo images at the same time is a step forward, not only for production of a digital elevation model (DEM) in vast areas and topographic maps, but also for automatic production of vertical images with very high geometric precision.
Iraj Jabbari (Translator)
Volume 12, Issue 46 , August 2003, , Pages 62-64
Abstract
The geomorphology engineering is the application of the principles of geology to solve the river engineering problems. The process-based understanding of the problem makes it possible that an engineering solution be implemented in parallel with evolution of system rather than imposing it on the system.Increasing ...
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The geomorphology engineering is the application of the principles of geology to solve the river engineering problems. The process-based understanding of the problem makes it possible that an engineering solution be implemented in parallel with evolution of system rather than imposing it on the system.Increasing the chances of success, reducing costs and decreasing the probability of a problem being uselessly circulated within the system are among the benefits of this view.
Fatemeh Razi'ei (Translator)
Volume 8, Issue 31 , November 2009, , Pages 62-64
Abstract
Geo-informatics is defined as a multi-purpose science dealing with measurement, recording, analysis and presentation of geographical data. Such land information is collected by RS, GIS and GPS. Each one of these three technologies, or each two of them, when combined with the other, create the new 3S ...
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Geo-informatics is defined as a multi-purpose science dealing with measurement, recording, analysis and presentation of geographical data. Such land information is collected by RS, GIS and GPS. Each one of these three technologies, or each two of them, when combined with the other, create the new 3S technology.Remote sensing provides images of environment and natural resources in a multi-spectral manner and with different resolutions in different times. GPS and also INS (Inertial Navigation System) reinforce the applied sensors through ground control points and photogrammetry. GIS deals with data and information taken by the help of modern tools from ground spatial data banks and bases which make decision-making possible.
Hushang Pulaki
Volume 1, Issue 3 , August 1991, , Pages 62-64
Abstract
One of the most important tasks of topographic maps is to show the nature in lifelike manner. Today, this is done in a variety of ways, such as shading the contour line, which in some cases is very difficult. Of course, this method is quick, but to some extent it has the weakness that it does not display ...
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One of the most important tasks of topographic maps is to show the nature in lifelike manner. Today, this is done in a variety of ways, such as shading the contour line, which in some cases is very difficult. Of course, this method is quick, but to some extent it has the weakness that it does not display the raised quality of certain points with acceptable quality.
In order to obtain the natural state of the Earth, research has been carried out which prove the superiority of the 3D view available in topographic map.
One of the most familiar and prominent types of these maps is the typical topographic maps (raised surfaces). In this case, the map will be raised on a plastic foil and with the help of heat. This map will face changes (movements of points on it) due to later changes in the foil, in a way that that this change will become greater as the height of the feature increases.
Mojtaba Fathi; Alireza Ma'manpush
Volume 18, Issue 72 , February 2010, , Pages 71-74
Abstract
Achieving stable agricultural production with proper profitability and, at the same time, preserving the environment from destructive effects of chemical fertilizers is not possible without taking the changes in farm’s soil and plant growth into account. The division of the farm into management ...
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Achieving stable agricultural production with proper profitability and, at the same time, preserving the environment from destructive effects of chemical fertilizers is not possible without taking the changes in farm’s soil and plant growth into account. The division of the farm into management sections is carried out in a variety of ways. Concentrated sampling of plants and soil, preparation of contour line maps of its features, and the use of aerial (installed on airplanes) and satellite sensors are among these methods. In developing countries, access to high resolution satellite data is not feasible due to economic and security reasons. However, satellite data with smaller scale is partially able to make the division of the management sections in the farm according to the state of plant growth possible. In this study, the possibility of dividing in-farm management sections based on the NDVI index calculated from the reflection intensity at Landsat 7 satellite wavelengths has been investigated. The NDVI map provides the possibility of dividing farm sections, calculation of the cropping area of each product, and the division of sections with different growth. The coefficient of variation of the NDVI growth index in the 10 hectare farm scale was about 11.5% and was significant. The observable growth rate of the field and the growth rate estimated according to the NDVI index field show agreement.
Habibollah Fasihi
Volume 16, Issue 62 , August 2007, , Pages 71-73
Abstract
Earthquake is part of the Earth’s natural behavior, occurring more than 150,000 times a year, but only a small number of them are associated with life and financial dangers and losses. Humanity has long been struggling with this phenomenon and has been horrified by it. There have been many human ...
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Earthquake is part of the Earth’s natural behavior, occurring more than 150,000 times a year, but only a small number of them are associated with life and financial dangers and losses. Humanity has long been struggling with this phenomenon and has been horrified by it. There have been many human settlements destroyed by the earthquake and their inhabitants immediately buried and annihilated under the debris. Unlike other natural hazards, earthquakes take place on a vast territory and bring about widespread damage and destruction. The sudden occurrence of earthquake and its unpredictability and the inability of man to control this phenomenon are also among the causes of human panic even in our time. Today, humans have been able to partly protect themselves from earthquake hazards by the construction of earthquake-resistant buildings. Although earthquakes might occur on any point of the earth, but the research suggests that it is more likely in the vicinity of active faults and therefore the severity and damage of earthquake is also more serious in these areas, because the concentration of energy inside the earth causes the flaws to move and take on a new state resulting in an earthquake. Ray is one of the ancient cities of Iran which, due to its proximity to active faults, has great potential for earthquake occurrence and has therefore suffered many devastating earthquakes causing a lot of damage and casualties throughout the course of history. The present paper first reviews the history of Ray’s earthquakes and then examines the probabilities of earthquake occurrence according to the location of faults.
Ezzatollah Ghasemifar; Siamak Taghizadeh
Volume 22, SEPEHR , July 2013, , Pages 74-82
Abstract
Borderline areas are very important and influential in the development of country and underdevelopment in these areas will be directly transferred to the whole country. Sistan-va Balushectan is a borderline area in Iran which lack an appropriate developmental status. In sum, major challenges facing Sistan-va ...
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Borderline areas are very important and influential in the development of country and underdevelopment in these areas will be directly transferred to the whole country. Sistan-va Balushectan is a borderline area in Iran which lack an appropriate developmental status. In sum, major challenges facing Sistan-va Baluchestan includes:
Geographical broadness with limited population (178431 km2 with a population of 1722579-Statistical center of Iran: 2006), long and insecure borders, natural obstacles like deserts, lack of natural blessings, geographic isolation, geomorphological factors, climatic situation and lack of oil and gas resources, settlement of Baluch tribes in both sides of the border, vicinity to Pakistan and Afghanistan, instability and weakness in providing complete political, administrational and economic sustainability which have resulted in lack of control on borderlines, political flow of Afghan refugees, vicinity to the largest drug producer and smuggler entering Iran through Sistan va Baluchestan borders, economic, cultural and social inequalities in this area as compared to central areas, poverty and deprivation which have resulted in a tendency toward smuggling. These challenges have resulted in numerous and various problems and issues which can threaten local, regional and even national development. If the present situation continuous, more severe difficulties can arouse. Therefore, the present article seeks to understand geopolitical features as an effective factor in underdevelopment of Sistan-va Baluchestan to gain a research-based perspective and create the foundations of sustainable development in the area.
Alireza Abbasi Semnani; Hojjat Mahkouii
Volume 20, Issue 77 , May 2011, , Pages 74-79
Abstract
Most people have ambiguous perceptions of geography. Many people think of geography as a science that merely studies mountains, rivers and nature. But since geography was introduced as a science and academic discipline and has played an important role in the advancement and development of places, different ...
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Most people have ambiguous perceptions of geography. Many people think of geography as a science that merely studies mountains, rivers and nature. But since geography was introduced as a science and academic discipline and has played an important role in the advancement and development of places, different views on geography have emerged among people. This scientific discipline has two main dimensions, namely, nature and man. These two dimensions mutually affect each other. In the human dimension, both men and women have important and major roles in affecting and being affected by the nature. Considering this fact, the role of gender in geography is emphasized, which has made one of the branches of geography, geography of gender, to be paid significant attention to by scientific and academic circles.Therefore, considering the role that human beings play in the development and planning of a geographic location, this role has been viewed as a unilateral and one-dimensional role in most societies, and women have not been as influential as men in gaining important occupations and influencing the planning process for development. Although in some countries they have obtained a significant role thanks to liberal democracy, they are still lagging behind in most societies. The purpose of this research is to investigate the role of gender and its impact on the advancement and development of societies. This paper has been carried out by descriptive-analytical method and the findings of the research are obtained by reviewing library documents. The main question in this article is: Is equality of sexes considered in geographic development of places? And its main hypothesis: equality between the two sexes (men and women) has a diminishing value and credibility in the geography of places.
Fatemeh Dehghannejad
Volume 21, Issue 81 , April 2012, , Pages 76-79
Hamid Kamrani Dalir
Volume 15, Issue 60 , February 2006, , Pages 76-79
Abstract
The spatial databases created on the basis of a systemic structure have prepared the conditions that provide users with the possibility of communication and exploitation among remote sites through the World Wide Web. Websites provide access to a variety of information about land features in graphic and ...
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The spatial databases created on the basis of a systemic structure have prepared the conditions that provide users with the possibility of communication and exploitation among remote sites through the World Wide Web. Websites provide access to a variety of information about land features in graphic and text documents. Global geographical databases are usually established and developed for various purposes. Perhaps software and information content will be continuously upgraded by using and expanding the database. Research on different aspects of the goals of global geographical databases requires other distinct studies. A brief overview of each of the bases is the topic of this paper.
Mohammad Mahdi Hoseinzadeh; Saeed Rahimi Harabadi
Volume 22, Issue 87 , November 2013, , Pages 77-80
Abstract
Exploring the changing processes of land forms is considered to be one of the key topics in geomorphological studies. Nowadays, geomorphological studies analyzes and clarifies geomorphic forms and processes at ground level. This shows the dominance of a systematic view in this field. In systematic view, ...
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Exploring the changing processes of land forms is considered to be one of the key topics in geomorphological studies. Nowadays, geomorphological studies analyzes and clarifies geomorphic forms and processes at ground level. This shows the dominance of a systematic view in this field. In systematic view, geomorphic analyses are performed based on the relation between land form and process. Geomorphologic threshold is one of the key concepts in systematic theory and thus is of significant importance in geomorphology. It indicates borderline situations during the occurrence of changes and shows temporal changes. The present article is based on secondary research and exploits theoretical and applied concepts related to thresholds, seeking to reach a balanced systematic analysis. It tries to study geomorphologic thresholds and classifications using different Persian and English resources. Moreover, we propose a short overview of some geomorphological issues, such as gully erosion, alluvial fan and river systems. Results indicate that geomorphic thresholds separates different situations of a system and are thus distinguishable. In fact, occurrence of a threshold changes the dominant processes in a geomorphologic system. This concept shows the situation in which a process operates to establish a new balance in the system. Siyum classifies geomorphic thresholds into two categories: 1) Internal which is related to the inside of a geomorphic system and 2)external which is under the influence of external variables such as climatic and tectonic changes.
Reza Esma'ili; Mohammad Mahdi Hosseinzadeh
Volume 18, Issue 71 , November 2009, , Pages 77-80
Abstract
The application of geological data in view of the recent advances in Paleoflood hydrology is essential as a complement to conventional hydrological approaches. The utilization of geological data such as sedimentology, stratigraphy and their combination with other sciences, such as geomorphology and hydrology, ...
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The application of geological data in view of the recent advances in Paleoflood hydrology is essential as a complement to conventional hydrological approaches. The utilization of geological data such as sedimentology, stratigraphy and their combination with other sciences, such as geomorphology and hydrology, have been particularly considered due to the existence of ambiguities in the mere use of applied statistics in flood studies. These data provide information from rivers without a hydrometric station. It is also possible to obtain longer information from hydrometric stations by using these data. The most important methods that are considered in this approach are: river flow regime method, Paleolithic Standard Indexes, river flow potentiality method, and botanical methods.
Rahim Sarvar; Mehran Rezaei
Volume 20, Issue 79 , November 2011, , Pages 78-84
Abstract
This paper was prepared in response to the UCGIS consortium in the summer of 1999. The objective of this challenge is to review the successes and inferences of geographic information science related to urban and regional planning. This study outlines five areas for the distribution of geographic ...
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This paper was prepared in response to the UCGIS consortium in the summer of 1999. The objective of this challenge is to review the successes and inferences of geographic information science related to urban and regional planning. This study outlines five areas for the distribution of geographic information science. The development of a geographical database will be helpful for analyzing the planning of combination of geophysical technologies with urban models, the development of planning support systems and facilitating participation in research and education challenges. While scientific advances in building tools are effective in supporting the planning process, little effort has been made on applied guidance in strategic information management. This weakness in the dissemination of the tools of planning limits the application of science for politics and decision making, which is necessary for environmental, social and economic development. The educational process, which is the first important step in technology transfer, contains many challangs, For example, the availability of suitable facilities for the training of planning professionals and other participants in the planning process, and the preparation of the required infrastructure for education and research. Therefore, further research and policy development in the following areas will increase the performance of planning support systems and tools: training and technology transfer, database building, protection and availability, standardization and regulation.
Nahid Sajjadian; Mahyar Sajjadian
Volume 19, Issue 75 , November 2010, , Pages 78-83
Abstract
Tehran is one of the most polluted cities in the world in terms of air pollution, and according to surveys, about 70% of this contamination is due to transportation and heavy traffic. Traffic monitoring is now being conducted using traffic lights and related equipment, as well as air pollution sensing ...
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Tehran is one of the most polluted cities in the world in terms of air pollution, and according to surveys, about 70% of this contamination is due to transportation and heavy traffic. Traffic monitoring is now being conducted using traffic lights and related equipment, as well as air pollution sensing stations. But the problem is that these systems lack the necessary ability of immediate reactions and traffic management in terms of time and location and according to air quality index. It seems that the use of an expert system based on GPS, dynamic GIS, and timed relationship databases is capable of providing intelligence and immediate operation to the traffic control system. The research method is analytical-practical. According to the findings of the research, the expert system, based on the correct use of GIS, GPS and timed relationship databases, is capable of providing intelligence and immediate reactions to a traffic control system based on air quality management. Finally, based on the findings of the research, a conceptual design of such an expert system was proposed.
Hiva Elmizadeh
Volume 20, Issue 80 , February 2012, , Pages 79-83
Abstract
The surface of the earth is composed of the continuity of a more or less extensive surface, which is called the slope. The main feature of this feature is its skewness. This surface is generally covered by soil and surface deposits. Since the soil is the most important element of the earth's biosphere, ...
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The surface of the earth is composed of the continuity of a more or less extensive surface, which is called the slope. The main feature of this feature is its skewness. This surface is generally covered by soil and surface deposits. Since the soil is the most important element of the earth's biosphere, without which the life in the land will not be running and durable, preserving and protecting it is of particular importance (Badrifar, 2000). Sometimes humans, by cultivating slopes and plowing in the direction of slope, have caused vertical cuts in the slopes; plowing the slopes and building irrigation networks along the level curves and also digging the canals along the direction of the slopes have greatly contributed to the intensification of the process of destruction and erosion of the soil and the elimination of this valuable material. In this paper, the status and shape of erosion in different directions of the slopes and the effect of morphology and slope on erosion and its type have been studied in Natchi basin. In this research, in addition to field studies, various documents such as topographic maps, geology, vegetation, aerial photos and satellite imagery have been used as research tools.
Gholam Abbas Ma'soumi
Volume 19, Issue 76 , February 2011, , Pages 80-88
Abstract
In the present era, the importance of productivity and the promotion of the performance of companies and organizations in a competitive environment has encouraged them to make more efficient use of computer networks. This is not only possible without the provision of fast, inexpensive, full time, easily ...
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In the present era, the importance of productivity and the promotion of the performance of companies and organizations in a competitive environment has encouraged them to make more efficient use of computer networks. This is not only possible without the provision of fast, inexpensive, full time, easily available, secure and sustainable services. Therefore, organizations and companies, in the competitive world, must purchase, install and maintain a variety of equipment and hardware, and pay their capital and communicative costs. High costs, lack of skilled human resources, and failure to meet the standards are among the problems of these organizations. To solve these problems, data centers have been developed. These centers, with extraordinary security, strong support, and specific conditions, provide a platform for organizations and companies to leave their data, programs and services to these centers to be used by themselves and their customers remotely. Sooner or later, most Government agencies will have to move towards data centers as a result of high data volumes, the lack of a centralized storage system, availability issues, and security problems. In this paper, using a federal organizational architecture framework, a methodology for architectural design of a data center is presented.
Saeed Khodaeian; Parviz Ziaeian; Saeedeh Fakhari
Volume 19, Issue 74 , August 2010, , Pages 81-85
Abstract
One of the most important climatic parts of the heritage of the fourth era in the highlands of Iran is the glacial geomorphology and the effects of the glaciers of that period. The Damavand glaciers, with more than 15 small and large tabs with signs of life and activity, are the only survivors of those ...
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One of the most important climatic parts of the heritage of the fourth era in the highlands of Iran is the glacial geomorphology and the effects of the glaciers of that period. The Damavand glaciers, with more than 15 small and large tabs with signs of life and activity, are the only survivors of those glaciers. Scattered studies have been conducted on these glaciers in recent centuries by Iranian and foreign scholars. However, a comprehensive report that describe and characterize the geomorphologic and morphodynamic characteristics of the glaciers in this region has not yet been compiled. In this paper, we try to interpret and analyze the shapes of glacier morphology, and to determine the extent and expansion of glaciers using remote sensing technology. The method of research is based on the fieldwork and the use of satellite imagery. The results show that the Damavand ice glacier is undergoing gradual shrinkage and melting under the influence of increasing temperature of the present age, and the existing ice cores are the remains of past glacial periods. The insignificant nutrition of glaciers through avalanches is not enough, but the effects and evidences of life are still evident.
Gholamhosein Rstegarnasab; Zahra Arzjani; Mansureh Banazadeh; Sara Bagheri
Volume 21, Issue 83 , November 2012, , Pages 82-85
Abstract
On the occasion of World astronomy day and the eighth student astronomy seminar, Mohammad ibn Zakariya Razi student research center in Shahr-e Ray launched an international project with the title of “Measuring Earth to Moon distance using non-Euclidean trigonometry” with the cooperation of ...
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On the occasion of World astronomy day and the eighth student astronomy seminar, Mohammad ibn Zakariya Razi student research center in Shahr-e Ray launched an international project with the title of “Measuring Earth to Moon distance using non-Euclidean trigonometry” with the cooperation of America, India, and Italy, Thailand. A large population of students in the participating countries took part in the project. Moreover, different national astronomy groups and societies cooperated. The present article seeks to provide practical astronomical and mathematical training on international level, so that students will be able to confirm figures and numbers discussed in scientific books and centers. In these measurements, students in Rey research center astronomy group took part in measuring the moon azimuth angle and its elevation in Picard region on its surface. The measurement results along with other tests performed by national and foreign groups showed an appropriate level of adaptability with pre-measured standard values.
Katayun Alizadeh; Hojjat Hasheminejad
Volume 21, Issue 82 , September 2012, , Pages 85-88
Abstract
The present article investigates the effects of economic situation on food security of different social groups in sample villages of Paeen Velayat in Mashhad (Khorsan Razavi province). Survey Research is used and data are collected using standard questionnaire. Statistical group consists of 404 households ...
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The present article investigates the effects of economic situation on food security of different social groups in sample villages of Paeen Velayat in Mashhad (Khorsan Razavi province). Survey Research is used and data are collected using standard questionnaire. Statistical group consists of 404 households or 1804 individuals from which 40 households were selected from the sample villages using cluster sampling. Results indicate that factors like geographic conditions of the village, land ownership, household head type and place of employment, number of children influence economic condition of the households and their ability in achieving sustainable livelihood. Moreover, there is a significant relationship between economic situation of household head and food security of dependent members of the family. In this regard, mothers and young girls experience the lowest and most fragile situation.
Jamal Mohammadi; Marzieh Heydaribakhsh
Volume 22, SEPEHR , April 2013, , Pages 87-97
Abstract
Growth in urbanism and industry have provided the urban environment with many recreational possibilities and citizens can spend their free time in different clubs, computer game centers, etc. Yet, using natural environment, green space and parks will always be interesting and desirable due to human nature. ...
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Growth in urbanism and industry have provided the urban environment with many recreational possibilities and citizens can spend their free time in different clubs, computer game centers, etc. Yet, using natural environment, green space and parks will always be interesting and desirable due to human nature. Providing a quiet, beautiful and healthy life for the citizens need a creative thinking. Creating beauty needs a beautiful mind, which in turn is created in a beautiful space. Decorative flowers in beautiful vases, soft sound of water, green trees and grasses, comfortable benches, appropriate statues create a peaceful space in the park in which urban raucousness is replaced with peace of mind. In order to develop urban parks into appropriate spaces without stress and unnatural elements, some standards and principles seem essential. Considering some standards in building benches, water tanks, lightening, etc. help us in achieving main goals of urban planning (health, tranquility, beauty). Although green spaces play an essential role in maintaining the balance, they cannot prevent damages threatening suburban spaces. Considering this, it is clear that without a general plan green space cannot have the necessary efficiency in reducing environmental pollution. Unfortunately, some items and issues are seen in parks surrounding Zayande Rud whose status is lower than the standard, among which we can refer to most of rest rooms, water tanks, children playing areas, etc.
Marzieh Khanahmadi; Mahdi Arabi; Alireza Vafaienejad; Hani Rezaiean
Volume 23, Issue 89 , May 2014, , Pages 88-98
Abstract
Constructing new urban facilities needs a precise investigation on the right method of establishing such facilities in different areas of the city. Selecting an optimal place based on different and sometimes controversial characteristics is the first fundamental issue in correct allocation of urban facilities. ...
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Constructing new urban facilities needs a precise investigation on the right method of establishing such facilities in different areas of the city. Selecting an optimal place based on different and sometimes controversial characteristics is the first fundamental issue in correct allocation of urban facilities. This is especially important if crucial issues like human life are also considered. Thus due to the importance of endangered human lives, optimal selection of fire stations is considered to be crucial. Considering the uncertainty about information sufficiency and comprehensiveness of inferences drawn by tools like spatial information system, fuzzy model is used in combination with analytic hierarchy process. In the beginning step of the study, influential factors in locating fire stations were determined and standard maps were produced and prepared. During the study, a survey performed on the experts opinions indicated that these criteria do not have the same influence in locating stations. Thus, these criteria should be assigned different weights based on their importance and influence. Analytic hierarchy process (AHP) and Export choice software were used to weight these criteria. After collecting expert opinions and in order to avoid possible non-expert opinions, adaptability of the judgments were calculated. After verifying CR values, these weights were used in subsequent steps. In the next step, fuzzy logic was used to rate these layers. Prepared layers were transformed into fuzzy logics using different membership functions which were selected according to experts’ opinion. Finally, AHP and weighted linear combination (WLC) were used to integrate fuzzy criteria with fuzzy membership functions and calculated weights, and in this way appropriate zones for building fire stations were identified and determined. Simply relying on the map results cannot have the necessary efficiency in locating an optimal place for the fire stations. Therefore, standard functional radius of available stations were determined using network analysis in GIS environment. Then, places with a high score for building stations and those covering whole area in a standard time were selected. This research seeks to display the efficiency of applying integrative logic for ranking layers using AHP in GIS environment. The integrated model benefits from high capabilities and it can be applied for different goals (selecting the optimal place for a site) and in different spatial situations.
Mozaffar Kazemizad
Volume 19, Issue 73 , May 2010, , Pages 94-96
Abstract
The hypothesis that air is affected by the phenomenon of full moon was examined in terms of cloud cover. The statistical analysis of data of 44 years showed that there is no apparent relationship between clear sky and the appearance of full moon (Badr).
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The hypothesis that air is affected by the phenomenon of full moon was examined in terms of cloud cover. The statistical analysis of data of 44 years showed that there is no apparent relationship between clear sky and the appearance of full moon (Badr).
Mohammad Motamedi; Arezoo Gholinejad Mir Abbasi; Mojtaba Sabet Kushkinian; Hojjat Hataminejad
Volume 23, SEPEHR , July 2014, , Pages 106-112
Abstract
Selecting a site for solid waste landfill is an important procedure in managing municipal solid waste and landfill sites should be selected with great precision and through a scientific process. Therefore, it is possible to select an appropriate site for solid waste landfill in accordance with environmental ...
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Selecting a site for solid waste landfill is an important procedure in managing municipal solid waste and landfill sites should be selected with great precision and through a scientific process. Therefore, it is possible to select an appropriate site for solid waste landfill in accordance with environmental criteria using geographic information system. The present article is descriptive-analytic. Secondary research and field study were simultaneously used for data collection. It seeks to locate an optimal site for solid waste landfill in Faruj city. In this study, we first investigated factors and principles of locating municipal solid waste landfill according to valid resources. Then, maps of influential factors on locating municipal landfill were prepared and valuated based on information layers and spatial analyzer tool, using geographic information system. According to geological indexes, distance from the river, distance from residential area, landfill is located in an inappropriate zone. Ultimately, the maps were integrated and combined. Analyzing the final map of Faruj solid waste landfill, we concluded that locating principles and standards were disregarded and the present landfill site is in an inappropriate zone.
Nahid Sajadian; Hadi Alizadeh; ali shojaeean; Hoseyn Saberi
Abstract
Abstract[1]
The basis of the emergence of new theoretical approaches in urban construction, design, and planning, such as green cities, healthy cities and ecological cities, is to pay attention to the urban environment and to pay more attention to the planning of green spaces use in the design and construction ...
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Abstract[1]
The basis of the emergence of new theoretical approaches in urban construction, design, and planning, such as green cities, healthy cities and ecological cities, is to pay attention to the urban environment and to pay more attention to the planning of green spaces use in the design and construction of densely populated cities in terms of physical and demographic aspects. Therefore, the existence of such use is vital and essential in today's cities. Therefore, in this study, with descriptive-analytical methodology, the aim of the study is to evaluate and analyze the optimal locations for the establishment of urban green spaces in Mahshahr city. In this regard, according to available data, the indices determining the goal of the research are 11 major urban users in the city of Mahshahr under the name of commercial, cultural, medical, educational, green space, industrial, religious, administrative, communication, sports, and tourist-historical places that have been used to analyze the optimal location of green spaces. To analyze the data, the indices of research (the classified 11 uses) were introduced into the fuzzy using Arc GIS 10 first, and then,were analyzed using the Fuzzy Gama (Fuzzy Gama) operator.The results of the study show that the threshold limit test of 0.7, 0.8 and 0.9 in the fuzzy gamma operator with regard to the existing conditions of applications, the fuzzy gamma with a threshold of 0.9 has analyzed the spatial location of urban green space in Mahshahr city better than the rest of the threshold values tested, taking into account the importance and balance In the decreasing and increasing trends of applications.Also, according to the results of this operator, the central parts of the city in both the western and eastern parts of the city are the most appropriate places for the establishment and location of urban green space.
[1] - به دلیل کیفیت نامناسب متن چکیده مبسوط انگلیسیِ ارائه شده توسط نویسنده مسئول مقاله، نشریه به ناچار اقدام به ترجمه مجدد متن چکیده فارسی و انتشار آن به جای چکیده مبسوط انگلیسی نموده است.
Reza Borna
Abstract
Abstract[1]
Locating industrial areas with consideration of social, economic and environmental consequences, is a key factor in regional planning. The suitable place for the establishment of industries has taken into account a wide range of criteria and it coordinates and brings together ...
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Abstract[1]
Locating industrial areas with consideration of social, economic and environmental consequences, is a key factor in regional planning. The suitable place for the establishment of industries has taken into account a wide range of criteria and it coordinates and brings together economic and social benefits with environmental sustainability.This research is an applied type that is carried out by a multi-criteria decision making method in the GIS environment.The information layers used in this research include precipitation layers, wind speed, soil, land use, elevation, waterway network, protected areas, industrial centers, road networks and cities.In this research, climatic criteria, natural factors, environmental factors and socio-economic factors were used to locate suitable areas for construction of industries, and after determining the effective factors in locating the industries, maps of effective factors in locating the industries were prepared by performing modeling and analysis of spatial data with the aid of GIS software.After weighing the layers based on the AHP model and using the EC2000 software, the capabilities of GIS software were used to integrate and overlap the maps and finally the map of the location of the industries was prepared.The results of the study indicate that the authorized areas for the location of high-class industries have allocated over 1566973.5 hectares of land in the studied area to itself. These areas are mostly located in the south, southwest, north, west, east and the center of Khuzestan province.
[1] - به دلیل کیفیت نامناسب ترجمه (چکیده مبسوط انگلیسیِ دریافتی) نشریه، به ناچار اقدام به ترجمه مجدد متن مختصر چکیده فارسی و انتشار آن به جای چکیده مبسوط انگلیسی نموده است.
Mohsen Saghaei
Abstract
Extended Abstract Introduction The worn out textures are one of a variety of urban textures that are spatially unstable due to physical deterioration and inappropriate enjoyment and the existence of vulnerable infrastructures and are one of the main challenges facing most cities and especially metropolises. ...
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Extended Abstract Introduction The worn out textures are one of a variety of urban textures that are spatially unstable due to physical deterioration and inappropriate enjoyment and the existence of vulnerable infrastructures and are one of the main challenges facing most cities and especially metropolises. Currently, 53 spots of worn-out texture spots have been identified in 15 regions of Esfahan which now have 350,000 inhabitants living in these areas. Meanwhile, the extent of the worn out texture in the Isfahan’s region 5 is 69.75 hectares. This article seeks the extent to which the identification and prioritization of worn out textures within the scope of the study area can affect the revival and reduction of their vulnerability. Methodology Regarding the purpose of the research, this research is an applied type and the method of studying and analyzing information and data is a descriptive-survey method. According to the country's standards, the criteria of the gravels fineness, impermeability, and instability have been taken into considerations, and analyses were carried out using the AHP model and the GIS software. Discussion The main objective of this research is to prioritize worn out textures for restoration and renovation, the first step of which is to identify such textures. The criteria and indices which have been considered in this research include: material genus, the degree of deterioration, the age and the extent of the real estate, and to analyze the desirability and prioritization of worn out texture in order to modify the texture erosion, the indexes should be scored after defining the criteria and indexes and performing the initial classification. In the next step, scoring of the internal values of each of the indices was done and in the final stage, the coefficient of importance of each criterion was determined using the AHP model and the Thomas hourly table and the criteria with the same weight were combined and the final output was obtained. Conclusion The results indicate that the lack of facilities, utilities and infrastructure has led to the migration of local residents to other areas and negatively impacted the population growth rate in recent years. On the other hand, due to the socioeconomic condition of the inhabitants of the texture, the process of reconstruction and renovation inside the texture has slowed down and this factor has exacerbated the deterioration of the texture.
hatem parnian; Karamatollah Ziyari; Mohammad Mirehie; Mahdi modiri
Abstract
Abstract [1] Land preparation of border regions, optimal exploitation of all human and spatial facilities of these areas in order to improve the material and spiritual condition of the society, Following the explanation of the theoretical foundations of the desirable organization of the sustainable spatial ...
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Abstract [1] Land preparation of border regions, optimal exploitation of all human and spatial facilities of these areas in order to improve the material and spiritual condition of the society, Following the explanation of the theoretical foundations of the desirable organization of the sustainable spatial of man, land and human activities in the border regions, are within the framework of the land preparation plan and the realization of development And national security, considering the characteristics of these areas. Indeed, it can be said that planning for the development of deprived and backward regions, especially the border areas, has become a necessity due to their position in the development and security in many countries, including Iran. This research is a descriptive-analytical research in terms of methodology and an applied-developmental one in terms of objectives. Data gathering method is in the form of library and field information, and the tools of interview and questionnaire have been used. The statistical population of this study includes experts in the field of border studies, of which 30 have been selected using purposeful sampling. Then, the analysis of the border inferential concept has been studied from the different points of view and inequalities have been identified by studying the situation of the development of regions. The location of the studied area in border exchanges has also been examined by presenting existing statistics. Then, using the SWOT analytical model, other capabilities and environmental problems of the studied area were investigated using a preparatory approach for development planning. The results indicate that the border regions are in a deprived condition in terms of enjoyment and the capacities of these regions have not been exploited properly too. An appropriate strategic plan can be taken to achieve the development of these regions. [1] - به دلیل کیفیت نامناسب ترجمه (چکیده مبسوط انگلیسیِ دریافتی) نشریه، به ناچار اقدام به ترجمه مجدد متن مختصر چکیده فارسی و انتشار آن به جای چکیده مبسوط انگلیسی نموده است.
Ali Mohammadpour; Amir Hamzeh Zarghami; Saeed Zarghami
Abstract
Introduction
The natural situation, way of dispersion of uses, position or placement of infrastructures and urban installations and equipment are assumed as safety considerations in analysis of topography and security planning and passive defense of city. Therefore, it is necessary to employ ...
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Introduction
The natural situation, way of dispersion of uses, position or placement of infrastructures and urban installations and equipment are assumed as safety considerations in analysis of topography and security planning and passive defense of city. Therefore, it is necessary to employ defensive and security approaches in the designs of urban development where this indicates both a link between performances of activities on one hand and defensive arrangements on the other hand. Fortification of urban defensive installations, anticipation of escape exits from risks, and improvement of the status of services which are required during the period of defense will be assumed as the foremost objectives in urban survey respectively. As the capital of Kurdistan province and the location of important administrative centers and the vital and significant facilities, the city of Sanandaj is of great importance. In addition, due to location of this city near Iraq and the same language spoken in Iraq’s Kurdistan region and recent presence of Israeli agents in this region, Sanandaj may be subject to political and military threats. With respect to the experiences of recent wars, especially U.S attacks on Iraq, the critical and vital points of this city have been recognized as centroids of the city, which, if damaged, could lead to the surrendering of the city. Therefore it is necessary to pay attention to the topology (positioning) of urban installations equipment with respect to passive defense approach in order to reduce such damages.
Materials and Methods
The methodology of this study is of descriptive- analytical type. In this regard, the authors have determined vulnerable points of this city in order to recognize the vulnerable elements and extents of this city by passive defense approach. Accordingly, a list of vulnerable elements of the city has been prepared using comments from 14 experts and these elements have been scored by means of Analytic Hierarchy Process (AHP) method. Initially data have been prepared as vulnerability maps based on any element in Arc Map software environment. Then weighting of elements have been done by AHP technique and binary comparison of them in ‘Expert Choice’ environment to solve AHP model. The order preference of parameters will be determined with respect to each other. The standardization (fuzzification) method has been adopted to determine the range of the city’s vulnerability based on scores. With respect to the conducted analyses on each of urban elements, the rate of vulnerability of Sanandaj city has been specified at five vulnerability level, i.e. very high, high, medium, low, and very low. Then SWOT model was employed to identify and to reduce vulnerability elements in Sanandaj city and Quantitative Strategic Planning Matrix (QSPM) model was employed for order-preference of strategies.
Results and Discussion
The highest vulnerability score belongs to vital artery (0.623). This criterion is divided into four following sub criteria in which reservoir and water treatment unit possess the highest scores. This is because of the location of this important infrastructure at the entrance of this city. Afterwards, crisis management centers are placed at second rank of vulnerability with score of 0.300. One of the reasons for concentration of offices at the central point of the city and inappropriate access of medical centers to communication network is related to pending position of city hill to hospital. The crisis management centers include two sub criteria of important offices and hospital and medical centers among which hospital and medical centers have been more vulnerable. After those, urban equipment and military, disciplinary, and supporting centers have higher vulnerability respectively. In terms of vulnerability rate, some of layers are overlapped to specify the most vulnerable parts in this city. The municipal region 5 and lesser part of regions 3 and 4 are vulnerable. Due to the placement of some centers with high- vulnerability in these regions, it is necessary to pay attention to passive defense principles out of which topology is one of their subsystems.
Conclusion
With respect to the implementation of scores from AHP model on maps of the studied zone, Sanandaj municipal region 5 has been known as the most vulnerable part of Sanandaj city because of its location in the vital artery and other important urban centers. Topology of vital and significant installations has not favorably followed passive defense approach. Thus, with respect to the derived information from the existing documents and evidences, the conducted field visits and analyses on the given centers represented that the principles of passive defense have not been observed in these installations and equipment. These centers have been located beside important and critical equipment in a centralized form and they have not been dispersed. This might increase the risk of attacks on these installations from the air and the ground. Similarly, duly efforts have not been made for camouflage and hiding these centers. What is clear so far is that, the subject of passive defense has not yet been addressed in urban designs prepared for the positions in Sanandaj city.
mahdieh soltani Gerdfaramarzy; gholamali mozafari; Shahab Shafie
Abstract
Extended Abstract Introduction Droughts are one of the most common climatic changes that occur in many arid and semi-arid regions of the world with high intensities every few years. In many years, the occurrence of droughts is also unknown for a while, therefore, the identification of drought itself, ...
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Extended Abstract Introduction Droughts are one of the most common climatic changes that occur in many arid and semi-arid regions of the world with high intensities every few years. In many years, the occurrence of droughts is also unknown for a while, therefore, the identification of drought itself, is considered as a valuable finding for managing the water resources in areas such as Iran, most of which are formed by arid and semi-arid regions. Precipitation is the most important determinant variable in drought conditions among climatic variables. Rainfall is the most important variable whose variations are directly reflected in soil moisture and surface runoff, variations in underground water reservoirs and others. The purpose of this research is to investigate the best method of drought interpolation in the Yazd-Ardakan plain, to identify areas at risk of this phenomenon and to identify its spatial distribution, and also to investigate the relationship between drought and the salinity of groundwater and the spatial distribution of saline water in the Great Plain of Yazd – Ardakan. Materials & Methods In this research, regarding the lack of long-term statistical period of some stations and considering the distribution of stations in this basin, the annual precipitation data of meteorological stations of Yazd - Ardakan plain during 2 long term period of 7 meteorological stations (1346-1391), and short term precipitation and salinity period of 41 meteorological stations and 47 underground water wells (1375 to 1391) have been used all together. The standardized drought index for the determining drought condition and descriptive statistics methods in SPSS software has been used to describe the state of groundwater salinity using Excel software. The Pearson, Man-Kendhal, and Spearman correlation analyses were also used to determine the relationship between drought and the state of salinity of groundwater. Finally, the Geographic Information System (GIS) was also used to map the zoning of groundwater salinity. Results & Discussion The results of the assessment showed that in the correlation analysis with all 3 Pearson, Man-Kendhal, and Spearman statistics, a negative trend along with inverse correlation is observed between the precipitation (SPI) and salinity based on the Z grade,, in none of which the significant level is observed. The existence of a strong correlation between these two parameters with a one year delay was among the other results of this research. Using GS+ and GIS, the best variogram model was selected and the maps of drought, groundwater salinity and salinity variations were also drawn. Generally, in most stations with negative precipitation trend, a positive trend of underground water salinity is observed, and groundwater quality has also changed more strongly in areas with more drought outbreak and its salinity has also increased. Conclusion The occurrence of droughts, on the one hand, increasing water demand in the area, on the other hand, exacerbate the shortage and need for water. Therefore, the monitoring of future droughts and wet years should be considered very important in terms of management strategies of the region. Passing such crises require the efficient management of water resources under present conditions, especially during drought periods. Usually, during such a period, the region’s water shortage, are provided from the groundwater resources and through increasing the water extraction from wells, to meet basic needs such as drinking. Therefore, in such cases, the quality issue of the extracted water from these wells becomes more important. The available statistics show that the water quality in the Yazd-Ardakan plain (electrical conductivity) is a function of annual precipitation (as the most important feature of droughts in the region), and with the annual precipitation increasing and decreasing, the groundwater quality also undergoes changes. In general, the results of the analysis of the studied parameters indicated that the climate of Yazd-Ardakan plain was associated with a rainfall reduction trend, which is one of the important factors of drought, so that, its consequences have also affected the level and quality of water resources. It has been observed in this research, that droughts have had a considerable effect on the salinity of groundwater in most of the areas. Therefore, it is generally stated that the groundwater quality has changed more strongly in areas with more drought outbreaks and its salinity has increased.
Mohammad Reza Baaghideh; Rasul Sarvestan
Abstract
Extended Abstract Introduction Like every other human activity, military activities are also affected by weather conditions. From a military perspective, climate studies are very important. In wartime, air and topography are more influential than any other physical factor, such as weapons, equipment, ...
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Extended Abstract Introduction Like every other human activity, military activities are also affected by weather conditions. From a military perspective, climate studies are very important. In wartime, air and topography are more influential than any other physical factor, such as weapons, equipment, and logistics. These factors have been somehow effective in most victories and defeats. Therefore, military forces need special equipment, special training and adaptation to environmental conditions. Military commanders pay special attention to the daily mean minimum and maximum temperature, as well as very high or very low temperature. Troops usually need two weeks to adapt to climate conditions, but in extreme heat they may never reach their full efficiency. The importance of climatology in military plans is summarized in two stages: first, a preliminary stage in which time and location for the establishment of bases and deployment of military equipment are predicted, and the second stage in which atmospheric phenomena are linked and connected with the planed military operations. Accurate understanding of climate elements and their effects can lead to the discovery of positive and negative points and, as a result, a better planning for the promotion of military operations. Therefore, researchers have always been interested in climate parameters and investigating the effects of these parameters on defense, military, and passive defense discussions have always been inevitable. Keywords: Military forces, climate, geographic information system, FTOPSIS Materials and Methods After performing secondary research and reviewing different resources, the most important climate parameters affecting the performance of military forces were identified and the initial database was formed. Data was received from Iran Meteorological Organization for 21 weather stations in Khuzestan province regarding a period of 25 years (1988-2013). Then, database was compiled using the received data and the geographic features of the stations (longitude, latitude and elevation). These parameters include: Long-term average annual rainfall, average number of dusty days in each year, mean maximum temperature, long-term average of wind speed, wind direction, long-term average of sunshine duration, average humidity In order to map climate parameters, each parameter-related layer was prepared using interpolation method and IDW model. Then, each layer was weighted using decision-making process. Afterward, each layer was classified into 5 categories, each of which was weighed according to its importance. In the next step, the fuzzy TOPSIS model was used to analyze collected data. Results and discussion Investigating the characteristics of precipitation layer and the weight of each category proved that the highest weight is related to the 670-570 category and the lowest weight is related to the 200-100 mm category. The highest level of precipitation (670-570 mm category) has occurred in Dehdez and Izeh, and the lowest level of precipitation (200-100 mm category) has occurred in Bostan, Hanijan, Mahshahr, Shadegan and Abadan stations. The maximum temperature layer in Khuzestan province showed that the highest temperature (44-48 ° C) had a weight of 4.52, while the lowest temperature in 19-26 ° C category had a weight of 0.73. Gotvand and Ahwaz agricultural research station have the highest wind speed (7.28-8.59 knot) and a weight of 2.17 and the lowest average wind speed (with the weight of 1.33) is recorded in Hendijan, Omidieh, Behbahan, Lali and Dehdez. The province wind direction layer showed that western winds had the highest weight (2.18) and southern winds had the lowest weight (0.96). Conclusion Understanding climate and its impact on transportation of troops, flight of fighters, movement of naval fleets, transport of heavy equipment, and performance of weapons in both sides of the war are among the most important determinants of victory or defeat in wars. Climate is one of the most important factor that directly affect military plans, and even national strategies, tactics, doctrines, command, organizational structure, optimal combination and type of navy-land forces, military and space equipment, collection of military information and clothes, maintenance, construction and support. In this study, eight factors including rain, temperature, dust, wind speed, wind direction, sunshine duration, humidity, and altitude were used in a combined approach. Geographic Information System and FTOPSIS model were applied in this approach. Results indicate that Khuzestan province is classified into five categories (from very unfavorable to very desirable) in regard to military activities. Most of the northeastern mountainous areas of the province are highly desirable, with excellent defensive capabilities. In Dehdez and Izeh, the proportion is somehow favorable. Eastern and southern parts of the province are very undesirable regarding the impact of climate parameters. The results also showed that wind speed and temperature are the most effective factors influencing the performance of military forces in the province.
Nazila Mohammadi; Mehdi Chabok
Abstract
Extended Abstract Introduction The construction of power transmission lines (PTLs) is one of the most important activities of the power industry of any nation in the development of power transmission network. Many technical, economic, environmental and social factors are involved in the issue of power ...
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Extended Abstract Introduction The construction of power transmission lines (PTLs) is one of the most important activities of the power industry of any nation in the development of power transmission network. Many technical, economic, environmental and social factors are involved in the issue of power transmission lines routing. These factors sometimes have co-directional and increasing effect and, in some cases, the effect is not co-directional and is even in opposite direction. Therefore, it is very important to determine the appropriate route for the power transmission lines which is in proportion with the needs and objectives of the project and to take the role of effective factors into consideration. Materials & Methods In this research, factors and criteria effective in power transmission lines routing were investigated in the form of three economic, access and maintenance objectives of the power transmission lines and adverse environmental effects. Given that, the problem is multi-objective, the criteria of more than one objective function must be optimized simultaneously. This data set includes Digital Elevation Model layers, land slope, villages, land use, roads, power transmission lines routes, geology, landslide, soil type, soil erosion, rivers and protected areas. In order to weight the factors and their combination, considering the features of each factor, the Fuzzy Analytic Hierarchy Process (FAHP) methods and the Weighted Linear Combination (WLC) have been used. FAHP is a very useful method for multiple-criteria decision-making in the fuzzy environment, which has provided substantial applications in recent years. Also, WLC is an analytical method which is used in the time of multi-criteria or more than one criterion decision-making. Any feature taken into consideration is called a criterion. Each criterion is weighted based on its significance. As previously mentioned, the issue of the power transmission lines routing is a multi-objective issue. Since there is no single solution to optimize each objective simultaneously, there is a set of Pareto optimal solutions. This solution is called non-dominated or Pareto optimal that the values of none of the objective functions can be improved without reducing the values of one or several other objectives. Considering the presented explanation, in order to determine the appropriate route with regard to the multi-objective problem, the Non-dominated Sorting Genetic Algorithm (NSGA-II) was used as an evolutionary multi-criteria decision-making method. The aforementioned model was used for the routing of 63 KV transmission lines between the two power stations of Shahid Salmani and Kiyasar in the city of Sari. The Arc GIS 10.3, Matlab and Google Earth were used in this research. Moreover, GIS was used for displaying, managing, analyzing and storing large and various datasets. Discussion and Results In order to solve the power transmission lines routing problem, different parts of this algorithm have been developed and expanded. In this research, an innovative operator was used for intersecting, mutating and non-dominated sorting. To determine the appropriate route based on the multi-objective, the algorithm must be run repeatedly and by using different parameters. In the present model, the objective functions are evaluated in every iteration in order to obtain the best result. In order to test and evaluate the efficiency of the algorithm, two samples of commonly used experiments in this field, i.e., repeatability test and parameter adjusting test, were used. The success rate of the repeatability and parameter adjusting tests for the presented model were 89% and 88%, respectively, which indicates the success of this model in both tests. The comparison of the best route generated from the proposed model with the existing power transmission line shows the improvement of the values of the objective functions, the reduction of 27 tension towers and 31 suspension towers and the reduction of about 6 km of the route length relative to the existing route of the power transmission line. Conclusion The Final Results of the Research Indicated that GIS capabilities can be properly integrated with the NSGA-II algorithm which, has appropriate capabilities such as, less computational complexity, high speed implementation of the algorithm and elitism process to solve the problem of routing the power transmission lines, and are exploited by applying appropriate changes in this algorithm, and by employing the FAHP method for any type of route and routing problem Particularly in the field of distribution, super-distribution and high voltage power lines. In future researches, in case of having more comprehensive information layers such as wind, temperature, precise geological information, agrology and technical and specialized calculations like tension and compression in the towers, combining the proposed method with dynamic programming algorithms in the tower locating sector and the possibility of taking various equipment in different environmental conditions into consideration can improve the process and quality of routing. Also, in the future works, it is possible to solve the problems of locating-routing of towers and passing the route of the transmission line by taking technical, environmental, social and economic factors into consideration, using modern methods or other methods for optimizing multi-objective evolutionary algorithms.
Seyed Saeid Nabavi; Hamidreza Moradi; Mohamad Shrifikia
Abstract
Extended Abstract Introduction There has been an increase in the occurrence of dust storms in the Middle East in recent years. The World Meteorological Organization has introduced dust storms as the result of atmospheric turbulence, which injects a large amount of dust into the atmosphere and makes the ...
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Extended Abstract Introduction There has been an increase in the occurrence of dust storms in the Middle East in recent years. The World Meteorological Organization has introduced dust storms as the result of atmospheric turbulence, which injects a large amount of dust into the atmosphere and makes the horizontal visibility less than 1000 meters. Iran is involved in dust storms due to its geographical location and weather conditions. Long-term evaluation of statistical data, identifying the origin and routing dust storms can be effective in identifying the time and location of this event. Materials & Methods In this research, the temporal distribution of Khuzestan dust storms from 2000 to 2015 was investigated at five synoptic stations including Ahvaz, Abadan, Aghajari, Safi Abad and Mahshahr. Given the World Meteorological Organization’s codes on the dust storm incidents, and in order to minimize human error, the information related to the event was extracted using the Linux operating system. Furthermore, Mann-Kendall test and Pearson and Spearman correlation coefficients were used to evaluate the trend of the temporal changes of dust storms and the rate of the correlation of the effective factors with the frequency of dust storm occurrence, respectively. Regression models were used to determine the rate of the effectiveness and the prioritization of the factors affecting storms. The entire statistical analyses were performed using the SPSS 20 software. Results & Discussion According to the results obtained, out of 1507 recorded dust storms, the Ahvaz station with 509 (34%) and the Aghajari station with 156 (10%) recorded events, have had the highest and the lowest number of recorded dust storms, respectively. The temporal variations trend of dust events at the study stations was not significant at the 1 and 5% levels. However, the frequency of dusty days in the Ahvaz and Abadan stations was positively correlated with the frequency of days with the region’s prevailing wind speed and direction at the 99% confidence level (p<0.01). There was also no significant correlation between soil texture and type. The results of linear regression model showed that there is a positive relationship between the frequency of dusty days with the frequency of days with the region’s prevailing wind direction at all stations at the 99 and 95% levels. Based on the standardized regression coefficient, at most stations, the occurrence frequency of the prevailing wind at the study stations has the highest impact on the occurrence frequency of dust storms. Conclusion: About 65 percent of dust events have occurred in two cities of Ahvaz and Abadan, located in the center and southwest part of the Khuzestan province. This could be due to the further proximity of these two stations to the local and regional dust sources. Another reason could be the flow of atmospheric circulations in different regions of the province. In this regard, the northwest-southeast winds which carry dust, hit Ahvaz and Abadan more frequently. The highest number of dust storms were recorded during summer and spring. A downward trend of dust events has been observed at all studied stations since 2008. Nevertheless, the problems caused by this event have become more apparent and have affected the lives of people. For this reason, the general view is that the number of dust storm events has increased. The high concentration and the higher persistence of dust storm events could be the reason of such an idea as well. These possible causes could be addressed in future studies in analysis and control of dust storm events.
Payam Jafari; Somayeh Sadat Shahzeidi
Abstract
Extended abstract
Introduction
Today, cities in different parts of the worldare exposed to damages from natural hazards for various reasons. These hazards which are associated with lots of financial damages, fatalities and injuries, are in need for urgent preventive measures. Based on the United Nation ...
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Extended abstract
Introduction
Today, cities in different parts of the worldare exposed to damages from natural hazards for various reasons. These hazards which are associated with lots of financial damages, fatalities and injuries, are in need for urgent preventive measures. Based on the United Nation International Strategic Plan for disaster reduction (UNISDR), all hazards have two natural and human activities origins.The province of Gilanis one of the northern coastal provinces, whose center is the city of Rasht. The objective of the present research is, analyzing and zoning geomorphic hazards in the province of Gilan. The method of this research is descriptive – analytical, and empirical. In the descriptive section, by using documentary studies and also in the analytical section, by identifying the effective parameters in the zonation of geomorphic hazards and integratingthem with the spatial analyses in GIS, vulnerable zones were identified in the study area.
In this research, the factors effective in the zonation of hazards were identified first. Then, in order to measure the significance of each of these factors, a questionnaire was prepared to carry out this important task by the method of ANP and by collecting the opinions of the relevant experts on each of the identified factors. After obtaining the opinions and using the fuzzy logic method, evaluation of each of the criteria and determination of their importance coefficients were done and based on its results, spatial evaluation was carried out using ARC GIS and high risks zones were identified.Results have shown that the use of fuzzy logic along with spatial analysis of GIS has been able to be used as an efficient tool in zoning geomorphic hazards and to prove the capability of the analytical model of research well.
Materials & Methods
The performing method of this research is descriptive-analytical, which is compiled using documentary studies of required information and dat. In this study, it was attempted to investigate the geomorphic hazards in the province of Gilan. At first, the study area was identified. In the next stage, information layers such as slope, topography, vegetation, the elevation map of land use and… were prepared using 1: 50000 topographic maps, 1:100000 and 1: 250000 geological maps, and Digital Elevation Model (DEM), and finally, the provided effective information layers by the experts’ opinion and the obtained field and documentary studies were investigated in the form of network analysis model. Network Analysis Process (ANP) is one of the techniques for decision-making. When several indicators are considered for evaluation, the evaluation task becomes complicated, and when the criteria are of different genders, the work will become more complicated, and the evaluation and comparison go out of the analytical state which the mind is capable of performing), and a strong tool for practical analysis is needed. Therefore, the network analysis process is capable of doing this (Shadfar et al., 2007: 66). The network analysis process is one of the multi-criteria decision-making techniques. This model has been designed based on the hierarchical analysis process and replaces ‘network’ with ‘hierarchy’. The main assumption in AHP is based on the independent function of the hierarchical upper groups from all of its lower parts and from the criteria of each level and class (Chang et al., 2005: 22 and De Seun, 2004: 636).Saatyhas proposed the use of the hierarchical analysis model (AHP) to solve problems with independent and dependent criteria and solutions, and has established and presented the network analysis model (Lee and Kim, 2001: 374). Thus, the ANP method was presented as an extension of AHP.
As the AHP provides a framework for hierarchical structures with one-way relationships, the ANP also provides the possibility of complex internal relationships between different levels of decision and criteria. The ANP feedback approach has replaced the network structure with hierarchical structure, suggesting that the relations between different levels of decision-making can’t simply be imagined as up-down, dominant-recessive or direct-indirect.In general, the ANP model consists of a hierarchy of control, clusters, elements, interrelationships between clusters and elements (Sarkis, 2002; 23; Oraet et al., 2006: 247). The geomorphic hazards of Gilan province were evaluated and zoned in 6 stages (Saaty, 1392).
1- First step:At first, given the field and library studies as well as the experts of the issue, the research-related elements were defined from 4 clusters with 11 elements. The relations between the variables and clusters were determined using correlation analysis.
2- Second step: the pairwise comparison matrix and the relative weight estimation: the determination of relative weightin ANP is similar to AHP, In other words, the relative weight of the criteria and the sub-criteria can be determined throughpairwisecomparison.Pairwise comparisons of the elements in each level are done similar to the AHP method because of its relative significance to the criterion of control.
3- Third step:the formation of primary super matrix. The ANP elements interact with each other. These elements can be the decision-making unit, criteria, sub-criteria, the obtained results, options, and anything else. The relative weight of each matrix is calculated based on the pairwise comparison similar to the AHP method. The resulting weights are entered in the super matrix, which indicate the mutual relationbetween the elements of the system.
4- Fourth step: the formation of a weight super matrix: super matrix columns consist of several special vectors that the sum of each vectoris equal to 1. Therefore, it is possible that the sum of each column of primary super matrixto be more than 1. In order to factorize the column elements proportional to the relative weight, and that the sum of the column be equal to 1, each column of the matrix is standardized. As a result, a new matrix is obtained, the sum of each column of which will be equal to 1. The new matrix is called the weight matrix. (FarajiShabbarbar et al., 2011: 56).
5- Fifth step:the calculation of the general weight vector: in the next step, the weight super matrix reaches to a power limit so that the matrix elements are converged and its row values are equal. The general weight vector is determined based on the matrix obtained.
6- Sixth step:the calculation of the final weight of the criteria: finally, the weight of each of the effective criteria is obtained. After determining the structure of the model and determining the weight super-matrices and the limit, the weight of each of the effective indices is obtained. After weighting the natural criteria effective in the zonation of the effective indices, using fuzzy logic technique in this stage, the maps of geomorphic hazards mapping of Gilan province are plotted
Results & Discussion
After determining the relationship between the effective criteria in geomorphic hazards, the experts’ opinions, the matrix of pairwise comparison, and the relative weight estimation, the formation of primary super matrix, the formation of weight super matrix, the calculation of the general weight vector, the calculation of the final weight of the criteria was carried out, using the mathematical operations in the ArcGissoftware. Then, using fuzzy logic technique, maps of geomorphic hazards zonation in Gilan province were drawn. Given the combination of all layers and the application of the coefficients obtained from the network analysis model, the final map of geomorphic hazard zonation was plottedand three vulnerable zones were obtained. 1- First zone - Northeast of the province: This is a zonewith high risks due to its location on the way of floods and geological features.
2-Second zone: south of the province: located in the vicinity of Roodbar and Rudsar, and to some extent Amlash, is considered as a part of high risky zones of the province. Closeness to the faultand relatively high slope are among the characteristics of this zone.
3-Third zone: center of the province: in the vicinity of the city of Bandar-e Anzali, Somesara is considered as high risk zones of the province. Flooding, high erosion, and slope movements to some extent are among the features of this zone.
Conclusion
Investigating the situation and the value of vulnerable human environments against various types of geomorphological hazards seems to be very important and essential. Natural hazards, especially geomorphic hazards, have already had and have lots of financial and losses and fatalities. On this basis, natural hazards were considered as one of the basic studies in order to be able to control and reduce natural hazards. Thus, the most risky zones of Gilan province were integrated into critical centers such as mines in the province. In order to model and predict the relative risk of geomorphic hazards in the present research, an ANP network analysis model was used. For each of the different values and ranges, a weight and score were obtained, for which the fuzzy sum of these scores and the integration of each layer in the obtained weight, determined the relative risk of the occurrence of geomorphic hazards. The results showed that three vulnerable zones in the northeast, south of the province I the vicinity of the cities of Roodbar and Rudsar, and to some extent,Amlash, and the center of the province in the vicinity of the cities of Bandar-Anzali, and Somesara, are risky and hazardous areas which are affected by the risks of flood and Geological features, proximity to faults and relatively high slopes, flooding, high erosion and, to some extent, movements of the slopes. The application of fuzzy logic along with spatial analysis of GIS has been able to be used as an effective tool forgeomorphic hazards zoning. In the end, it is necessary to note that the location of some of the zones at low levels of vulnerability and risk does not represent their idealsituation and determines only the place of the aforementioned zone in relation to other zones.
Omid Reza Kefayat Motlagh; Mahmood Khosravi; Sayyed Abolfazl Masoodian
Abstract
1-Introduction The sun is the primary source of energy and life for Earth, and without solar radiation, there will be no atmospheric and climate processes on the Earth. Animal, human and plant life on the Earth depend on the energy received from the sun. Shortwave solar radiation is very important, due ...
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1-Introduction The sun is the primary source of energy and life for Earth, and without solar radiation, there will be no atmospheric and climate processes on the Earth. Animal, human and plant life on the Earth depend on the energy received from the sun. Shortwave solar radiation is very important, due to its role in biological processes, especially photosynthesis and human life. Outgoing Long Radiation (OLR), which is the result of heat reflection from the Earth’s surface, plays a vital role in the thermal balance of the Earth with regard to the presence of greenhouse gases. Part of the OLR goes out through atmospheric windows, but a large part of it is returned to the Earth by greenhouse gases, and plays an important role in the Earth’s thermal balance, especially during nights and in winters. Estimating Outgoing Long Radiation (OLR) is very difficult and remote sensing can be used to evaluate OLR on a planetary and regional scale. The purpose of this study is to examine long-term average of outgoing longwave radiation (OLR) over Iran using data received from the Iranian National Center for Oceanography and atmospheric science. Solar radiation is one of the most important parameters affecting the Earth atmosphere thermal balance (Isoman and Mayer, 2002). It also forms the basis for most of climate studies, because the process of evapotranspiration depends on the amount of available energy for evaporation (Alan et al, 1998). Since 99.8 percent of the energy at the Earth’s surface comes from the sun, the effect of solar radiation on evapotranspiration has been of great interest to researchers working in the field of agricultural science, especially irrigation sciences (De Souza et al, 2005). Some studies have used OLR trend to explore feedback and climate processes (Chu and Wang, 1997; Suuskind et al, 2012). Chuudi and Harrison studied El Niño’s impact on seasonal rainfall, temperature and atmospheric cycles’ anomalies in the U.S. using OLR. In another study, they have also estimated global seasonal rainfall anomalies related to El Niño and La niña using OLR (Chiody and Harrison, 2013, 2015). Knowing the amount of solar radiation in different locations is important for many practical issues such as estimating evapotranspiration, architectural design, agricultural products growth models, and etc. (Moradi, 2005; Alizadeh and Khalili, 2009; Mousavi Baygi et al, 2010). Considering the importance of climate change effects on the fluctuations of short wave and long wave radiations from the Earth surface and its relation with regional climate, research on this issue seems necessary. Since this issue has been underestimated in our country, and most researchers have only tried to find different coefficients and equations for estimating received solar radiation based on other meteorological parameters, making previous sporadic studies and researches on outgoing longwave radiation changes over Iran and other parts of the world applicable seems to be necessary. 2- Materials & Methods In this study, HIRS satellite data were used to analyze long-term average of OLR on planetary and regional scale. NOAA satellites were launched by the National Oceanic and Atmospheric Administration of the United States. The latest satellite in these series (version 19) was launched in February 2009. This polar-orbiting satellite circles the Earth from the North Pole to the South Pole 14 times a day. This allows NOAA-19 to observe the whole Earth twice every day (NOAA website). Since the purpose of the present study is to examine long-term average of outgoing longwave radiation over Iran based on data received from NOAA, daily OLR averages were retrieved from the CDR database with 1 arc degree resolution on a global scale for the period 1/1/1979 - 12/29/2016. Then, Iran long-term average of OLR and also its global average were calculated based on nearly 1 billion cells. The Gi* analysis method was also used to study the spatial distribution of outgoing long wave radiation over Iran. Since data received from outside Iranian territory were also included, we used “In polygon” function in MATLAB software to extract data specific to geographic borders of Iran. 3- Results & Discussion After calculating long-term average, results indicated that maximum OLR occurs between 30˚ north and south latitude, especially over the Middle East and North Africa, which is due to the radiation angle and ground cover. Results also showed that long-term average of the OLR was 222 W/m2. However, the mentioned areas have a reflection of more than 280 W/m2. Maximum OLR (289W/m2) occurs over Rub’ al-Khali desert and minimum OLR occurs over Antarctic glaciers (126 W/m2). These two points are one of the warmest and coldest areas on the Earth, respectively. They also have different ground cover. Therefore, it is natural to have a 173 W/m2 difference between the highest and lowest outgoing long-wave radiation over the Earth. Regional scale findings indicated that long-term average of OLR over Iran is 265 W/m2, which is 43 W/m2 (19 percent) higher than the global average. Results also showed that maximum OLR occurs to the west of Poshti region in Konnak city, Sistan and Baluchestan province (289 W/m2), and minimum OLR occurs over Ararat mountains in north-west Iran (approximately 235 W/m2). This 50 W/m2 difference is due to different latitude and altitude of these locations, which shows the significant role of temperature in the amount of outgoing long-wave radiation. 4-Conclusion Findings indicated that average global OLR is 222W/m2 and maximum reflection over the Earth surface occurs between 20˚ north and south latitude. This is because the average reflection between these latitudes reaches 270 W/m2, which can be attributed to the proximity of Tropic of Cancer and Tropic of Capricorn. Findings also showed that average long-wave radiation over Iran (264 W/m2) is %19 higher than the global long-term average. Although, maximum global OLR occurs in Rub’ al-Khali desert in Saudi Arabia (299W/m2), Iran is also considered to have a high level of OLR due to its geographic location and limited ground cover. With a reflection of more than 280 W/m2,vast regions in southern Iran are considered to have excessive energy and thus play an important role in environmental warming. Spatial analysis of hot and cold spots concentration patterns (above 90% level of confidence) showed that nearly 40 percent of Iran is considered to be hot spots, 17 percent neutral and 43 percent cold spots, the pattern of which is affected by difference in latitude and ground cover.
Sara Nakhaee Nezhad Fard; Hamid Gholami; Davood Akbari; Matt W. Telfer; Marzieh Rezaee
Abstract
Extended Abstract Introduction Among all Earth’s ecosystems, arid and semi-arid regions (about 30% of the Earth’s land) have experienced significant degradation over the past century due to the intensive land use practices and the increasing effects of droughts and climate changes (Maynard ...
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Extended Abstract Introduction Among all Earth’s ecosystems, arid and semi-arid regions (about 30% of the Earth’s land) have experienced significant degradation over the past century due to the intensive land use practices and the increasing effects of droughts and climate changes (Maynard et al., 2016). Remote sensing is capable of detecting several groups of disturbances and changes, and has been widely used as a toolto identify long-term changes. Recent technological advancements in the methodology of mapping and monitoring land cover changesprovide new opportunities for the utilization of satellite imageries with high temporal frequency. Image fusion technique has been applied in different fields of environmental science, such asmapping crop growth, studying daily pollution of water resources, studying patterns of short-time ecological changes, determining regions with short-term erosion risk, etc. Image fusion algorithms include color combinations in three bands ofRGBimages, statistical and multi-scale methods. The present study seeks toevaluate the efficiency of image fusion algorithms and select the best algorithm for mapping vegetation in SouthKhorasan Province. Materials and Methods Following the pre-processing ofLandsat 8 and MODIS images, six image fusion algorithms, including NNDiffuse, HPF, Brovey, Gram-Schmidt, PC and CN, were studied and evaluated usingdifferent statistical criteria. Three statistical indices, including Root MeanSquare Error(RMSE), Mean Absolute Error(MAE) and Mean Error (MEB)were usedto evaluate the aforementioned algorithms.Then, the best image fusion algorithm was used to merge two different images received from Landsat8 (30m) and MODIS (250m). Finally, two vegetation indices, including NDVI and HVCI, were usedto map vegetation in SouthKhorasan Province. Results and Discussion Results indicate that all six algorithms used in the present research can improvespatial resolution of the merged images. Compared to other 5 algorithms, NNDiffusecan merge thered and NIR bands of Landsat 8 and MODISwith a relatively higher accuracy. Therefore,NDVI extracted from this algorithm has the lowest RMSE and MAE compared to the original Landsat 8images. NDVI obtained from thefusion algorithms used in systematic-random transects of three land uses (including agricultural, urban and pastures) indicate that the index obtained from NNDiffuse algorithm has a better conformitywith the NDVI obtained from the original Landsat 8image. Then,redand NIR bands of Landsat8 and MODIS were combined forsimultaneous mapping of NDVI and HVCI in the case study area. Overall, a great part of SouthKhorasan Province has a vegetation cover of less than 10% and 40-50%, vegetation cover is only limited to small parts of the study area (agricultural land use and gardens). Conclusions Generally, accessing simultaneous satellite images with high spatial resolutions, such as the Landsat series, is considered to be a challenge in vast area. The present study took advantage of different algorithms for image fusion and vegetation mapping in South Khorasan Province. Image fusion techniques, such as integration of Landsat and MODIS images, can be very useful for mapping purposes. Evaluation of 6image fusion techniques indicated thatNNDiffuse algorithm is the most suitable method for mapping vegetation in the study area.
Extraction, processing, production and display of geographic data
Seyed Hossein Mirmousavi
Abstract
Extended Abstract
Introduction
In hydrological drought, water scarcity spreads through the hydrological cycle and can subsequently reduce groundwater levels, surface water and lake levels, and this means that hydrological drought dominates those areas, leading to long-term effects. In addition, due ...
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Extended Abstract
Introduction
In hydrological drought, water scarcity spreads through the hydrological cycle and can subsequently reduce groundwater levels, surface water and lake levels, and this means that hydrological drought dominates those areas, leading to long-term effects. In addition, due to climate changes and rainfall and temperature anomalies, droughts have increased in frequency and severity in many regions of the world. The predicted changes for the coming years show that climate variables will not have uniform changes in all regions and regional changes in the amount of precipitation may lead to the creation of hydrological patterns much different from the current conditions.
The present study was also carried out with the aim of spatial analysis of drought effects on water level changes in the catchment area of Bakhtegan, Tashk and Maharlo lakes. In this research, an attempt has been made to identify temporal and spatial patterns of changes in the level of this lakes by using satellite images and spatial analysis models.
Materials and Methods
In the present study, Landsat 5(TM), 7(ETM+) and Landsat 8(OLI) satellite images with a resolution of 30 meters have been used in the period of 2000-2021 to investigate water level changes. Due to the fact that the water level of the studied lakes changes drastically with the rainfall of different months, therefore, it is difficult to determine the amount of water cover for a year without considering the fact that a part of this cover is seasonal and when the rainfall decreases, a part of the lake Dry may not provide accurate results. Based on this, in the present study, one image was used for each month for each year studied to evaluate the changes in the water level of the lakes in all months of the year.
Conclusion and Discussion
The investigation of the changes in the water level of Maharlo Lake shows that in the drought of 2108 and 2017, the permanent water level of the lake has decreased to 1.8 square kilometers. Meanwhile, in the severe and very severe drought of 2005 and 2004, the permanent water level reached 170.4 square kilometers. Examining the changes in the area of Tashek Lake in 15 years of drought shows that the area of the waterless part of this lake has increased more than the seasonal and permanent water. The highest amount in this field was in 2021 with a very severe drought, which shows that this lake has more critical conditions in terms of permanent dryness than Maharlo Lake. This lake has been in a terrible state for 5 years. Comparing the changes in the area of Bakhtegan lake in different years shows that this lake has a more critical situation than its neighboring lakes (Maharlo and Tashk), so that in a significant number of years (12 years) the lake lacked permanent water and only With monthly or seasonal rains, some water has been temporarily collected on its surface, but it has a short shelf life between 2 to 6 months (November to May).
Results
The results of the evaluation and analysis of the role of drought in the water level changes of the Bakhtegan, Tashk and Maharlo catchment lakes showed that the area of these lakes has decreased significantly during the studied period, so that over time the area of the water area has decreased. It has been permanently reduced and added to the dry and waterless area. The maximum decrease in the water level of all three investigated lakes occurred during a 6-year drought between 2008 and 2013, in such a way that the area of the part with permanent water was greatly reduced and the area of the dry part of the lakes was increased.
