Mahdi Modiri
Volume 8, Issue 32 , February 1999, Pages 2-3
Abstract
The basis of decision-making and selection of Geographic Information Systems (GIS) is the quality of geographic information. Many executive centers of geographic information systems and their users usually seek application and utilization of more powerful computers with various abilities such as high ...
Read More
The basis of decision-making and selection of Geographic Information Systems (GIS) is the quality of geographic information. Many executive centers of geographic information systems and their users usually seek application and utilization of more powerful computers with various abilities such as high volume of memory, power of processing and graphic display (size, color and form of display) as well as a variety of programs capable of analysis and modeling, and concern less about the quality of information. It is so while today many of GIS managers’ expectations have not yet been fulfilled and many promises have failed despite vast investments in provision of hardware systems and collection, provision and storage of geographic data.Quality of information is one of the most important issues that has received less attention. Quality of information is in direct connection with precision, clarity, scientific bases of combination of information, analysis and modeling.In general, effective and determining factors can be categorized into four branches: geographic information database; structure of information; storage, search for data, distribution and propagation of information; and cartographic process of information and its necessary considerations.
Seyyed Yahya Safavi
Volume 8, Issue 32 , February 1999, Pages 4-7
Abstract
Political geography is one of the branches of geographical sciences that examines all natural, cultural (human) and environmental effects on policies, military plans and combative / supportive operations at global, regional and local levels.Political geography is a science that expresses the effects ...
Read More
Political geography is one of the branches of geographical sciences that examines all natural, cultural (human) and environmental effects on policies, military plans and combative / supportive operations at global, regional and local levels.Political geography is a science that expresses the effects of geographic factors of a country or area on military movements.Political geography is a part of military sciences that concerns environmental characteristics of the area of operation.Political geography includes application of geographic analysis method. It is worth noting that various definitions have been presented for political geography, but two major points are necessary to be considered in order to reach a comprehensive definition.
A. Scale and application of military geography The application of military geography for political leaders, national security planners, commanders and military hierarchies that play major roles in formulation of military strategies, which has specific definition and a certain scope. B-The military geography has its own value against internal and external threats and various geopolitical conditions of any region. In fact, military geography faces threats by presenting their direction and exploitation of geographic factors against these threats. Military geography is an effective guide in national and macro planning in a country including land preparation and allocation, so that appropriate locating of development plans and constructive measures of the country such as infrastructure and industrial establishments take defense-security considerations into account in all circumstances.
Hamid Malmirian (Translator)
Volume 8, Issue 32 , February 1999, Pages 8-10
Abstract
Remote sensing is the art of obtaining information about an object, area or phenomenon through analysis of data gained by tools that are not in physical contact with the case studied. In many ways, remote sensing can be considered as a “reading” process. Using different sensors, data that ...
Read More
Remote sensing is the art of obtaining information about an object, area or phenomenon through analysis of data gained by tools that are not in physical contact with the case studied. In many ways, remote sensing can be considered as a “reading” process. Using different sensors, data that can be analyzed with the aim of obtaining information about phenomena studied is collected remotely. Such data might be in different forms, including changes in distribution of forces, propagation of sound waves or electromagnetic energy. Finally, these data are processed for users who need to use them for their decision-making systems. In this paper, the basic rules of this field are studied under the title “remote sensing processing”. The discussion begins with bases of electromagnetic energy, and then the collision of energy with the earth’s atmosphere and surface features are examined. In addition, the role of reference data in analysis methods is evaluated. These bases will help us identify an ideal system of remote sensing. The limitations of remote sensing systems can be studied based on this framework. GIS bases will be discussed briefly as well. Eventually, it is hoped that reader of this paper will gain a general understanding about principles, concepts and applications of remote sensing and the close connection between this technology and GIS.
Bahman Ramezani
Volume 8, Issue 32 , February 1999, Pages 11-16
Abstract
Shortage of water resources and climatic limitations of the period of plants’ growth, excessive precipitation and lack of enough precipitation lead to drought or, in other words, decrease of agricultural products. This topic is considered from different points of view by experts of different fields, ...
Read More
Shortage of water resources and climatic limitations of the period of plants’ growth, excessive precipitation and lack of enough precipitation lead to drought or, in other words, decrease of agricultural products. This topic is considered from different points of view by experts of different fields, but in general it is considered as a natural phenomenon with many effects on the environment.According to a study of the temperature-precipitation trend over a certain statistical period at twelve stations, impact of drought is gradually appearing, and alleviating measures cannot be a real cure for this climatic factor. Evidences show that the length of the active thermal period of crops’ growth, extra precipitation and temperature variations in the region are gradually undergoing significant changes, and, considering population increase and limitations of soil, they might bring about numerous environmental problems in future.The present study is a part of a research plan, still in the process of edition, which analyses the trend of change of above factors using mini-tab software and predictive maps of probabilities with different periods. The aim of this study is to identify the trends and to provide with a vision of future, so that due measurements for dealing with this issue (drought and its environmental effects) in a humid climate or area can be duly considered by local planners.
Ashraf Azimzadeh (Translator)
Volume 8, Issue 32 , February 1999, Pages 17-19
Abstract
Once technology overshadowed humans’ imagination, but now those minds have risen in protest against the technology. According to Robert Barr, we must learn how to distribute and spread data, instead of merely piling them up.Advancements in development of GIS have made this industry available to ...
Read More
Once technology overshadowed humans’ imagination, but now those minds have risen in protest against the technology. According to Robert Barr, we must learn how to distribute and spread data, instead of merely piling them up.Advancements in development of GIS have made this industry available to everybody through computers and especially the internet and intranet, and have thus spared us the trouble of seeking data sources and methods of processing.All these developments must have made life easier for us, but with reduction of technical barriers, political and economic obstacles have replaced them. If we are able to transfer data freely from one place to another, or if we can store them with insignificant cost, one question still remains: where should we store information? It is not correct to claim that we can answer: wherever it is suitable” or “we can transfer them whenever necessary”, because such attitude is out of question in today’s world.At least four factors concerning information are required to be clarified for answering this question: costs of storage and transfer, right of possession, methods of conversion and process of integration.
Ghodratallah Abedi
Volume 8, Issue 32 , February 1999, Pages 20-30
Abstract
Earthquake, as the most horrifying and tragic natural disaster, knows no limitations. Since Iran is located on one of the most active seismic belts in the world (the Alps-Himalaya orogenic belt), it is considered as one of the most earthquake - prone countries in the world. Kerman Province, due to its ...
Read More
Earthquake, as the most horrifying and tragic natural disaster, knows no limitations. Since Iran is located on one of the most active seismic belts in the world (the Alps-Himalaya orogenic belt), it is considered as one of the most earthquake - prone countries in the world. Kerman Province, due to its position on this belt, is seriously vulnerable to dangers by this natural disaster. Earthquakes occurred in this province have always entailed vast human losses and economic damages. In this paper, it has been tried to study the recorded data and the geomorphological map of the area, and to determine sensitive and vulnerable points over the province and provide the economic and social planners and managers and officials of emergency aid organizations with suggestions for reduction of the effects of natural disasters.
Hosein Ghahra'ei (Translator)
Volume 8, Issue 32 , February 1999, Pages 31-35
Abstract
It was previously thought that the probability of existence of life on Mars is more than other places in the space. Although Mars is half the size of Earth, it is similar to our planet in other aspects. Days in Mars are half an hour longer than our days, and it has a cloudy atmosphere. There are ice ...
Read More
It was previously thought that the probability of existence of life on Mars is more than other places in the space. Although Mars is half the size of Earth, it is similar to our planet in other aspects. Days in Mars are half an hour longer than our days, and it has a cloudy atmosphere. There are ice caps there that melt during summer and expand over winter. There are also plains in there. Most interesting of all are the signs that change every year in terms of size and shape and look almost like plants that are growing. Some of astronomers have even thought that they could see canals dug by Mars residents to transfer water from poles to plains.Space explorations have revealed many facts on Mars, but no sign of life has been discovered there. First, it is very cold there; even in a summer day the temperature will not rise above the freezing point of water. Second, the thickness of air layer on this planet is similar to thickness of air layer at an elevation of about 35 kilometers (22 miles) from Earth’s surface, so it is not possible to breathe in there. Ultraviolet radiations of the Sun reaching the surface of Mars are so strong that they would destroy every living being.There is water on Mars’s surface, but it is not in liquid form. This water lies in frozen state under the surface and within ice caps. However, water has probably existed in liquid form in the past. Some of the signs over the planet look like dried-up rivers. Maybe Mars have been warmer in the past, so that water could have been melted.River beds are not like canals on Mars. They are apparently illusions that deceived astronomers when looking through their telescopes. The dark points that once were supposed to be plants are in fact areas of dark rocks and dust. They change every year in terms of size, because dusts are dispersed by winds.
Abbas Khosravi (Translator)
Volume 8, Issue 32 , February 1999, Pages 36-38
Abstract
In Jyderup, a city in the state of West Zealand in Denmark, two water wells of an underground water supply network, set-up about twenty years ago, are less than a hundred meters away from a deserted color factory. Considering the authority of chief officials of the Environmental Organization of West ...
Read More
In Jyderup, a city in the state of West Zealand in Denmark, two water wells of an underground water supply network, set-up about twenty years ago, are less than a hundred meters away from a deserted color factory. Considering the authority of chief officials of the Environmental Organization of West Zealand, a simple question was to be answered: is there a danger of contamination of underground water wells due to chemical substances released by the factory? If so, is there the possibility of removing these contaminations by digging new wells and extracting polluted underground water?
Hamid Enayati (Translator)
Volume 8, Issue 32 , February 1999, Pages 39-42
Abstract
This paper is about extraction of information by the method of digital photogrammetry for preservation of cultural works. The precise digital model of elevation can be created through such study using a PC (Personal Computer). This model can be combined by visual data to be utilized for protection of ...
Read More
This paper is about extraction of information by the method of digital photogrammetry for preservation of cultural works. The precise digital model of elevation can be created through such study using a PC (Personal Computer). This model can be combined by visual data to be utilized for protection of cultural works.
Zoleikha Bagheri (Translator)
Volume 8, Issue 32 , February 1999, Pages 43-50
Abstract
The International Astronomical Union has recognized eighty-eight constellations in different sizes and shapes. Their longest is Hydra, which covers almost 1303 square degrees of the sky’s surface, while Crux is only 68 square degrees. Centaurus contains forty nine stars with apparent magnitude ...
Read More
The International Astronomical Union has recognized eighty-eight constellations in different sizes and shapes. Their longest is Hydra, which covers almost 1303 square degrees of the sky’s surface, while Crux is only 68 square degrees. Centaurus contains forty nine stars with apparent magnitude higher than 5, while Mensa does not include even one star of such brightness. Over the year, the Sun passes through twelve constellations of Zodiac. It should be noted that the position of bright stars is more in South than in North.
Abbas Ali Salehabadi
Volume 8, Issue 32 , February 1999, Pages 51-56
Abstract
When in 1986, GPS satellites were launched into space, nobody could have predicted that this system should overtake traditional and classic methods in surveying activities (such as triangulation and traverse). Since then, almost two generations of GPS receivers have been produced. With advancements in ...
Read More
When in 1986, GPS satellites were launched into space, nobody could have predicted that this system should overtake traditional and classic methods in surveying activities (such as triangulation and traverse). Since then, almost two generations of GPS receivers have been produced. With advancements in human technology and knowledge regarding production of precise computers on smaller scales and with higher speeds of processing, new generations of GPS receivers have become smaller, lighter and of greater power and potential of implementation and storage of satellite measurements in comparison with old receivers. Considering these facts, the new generation of GPS receivers introduced into mark from the year 2000, offer vast hardware and software abilities with wonderful efficiency. These receivers, along with small size and lightness, have high power of initial processing in connection with preparation of positional information. These receivers are able to store information in the main memory up to 16 Mb. They can also receive all the information sent on L1 and L2 carrier frequencies. Therefore, it is possible through utilization of such receivers to achieve the same precision that old receivers obtained by observations as long as about thirty minutes. One of the innovations used in new generation of GPS receivers is a computer chip (IC) that has an astonishing power for removing effective systematic errors that affect GPS measurements, and therefore can provide new GPS receivers with the possibility of precise positioning. This computer chip, known as Paradigm Chip, acts like a small computer “brain” that controls all observational and calculative activities in the receiver.
Hasan Beik Mohammadi
Volume 8, Issue 32 , February 1999, Pages 57-64
Abstract
Migration is one of the demographic and population analysis characteristics that is related to residential movement of people from one place to another. This movement takes place under the effects of attractions and repulsive facts of different areas, and creates especial economic-social and cultural ...
Read More
Migration is one of the demographic and population analysis characteristics that is related to residential movement of people from one place to another. This movement takes place under the effects of attractions and repulsive facts of different areas, and creates especial economic-social and cultural effects on either of migrant’s sending and receiving places.Isfahan Province has experienced intense demographic transfer over the past decades due to imbalance in economic planning and concentration of industrial investments in a small part of the province as well as polar development and inattention to spatial development, so that between the years 1986 to 1996 more than 591,000 people (about 15% of the province’s population) have entered this area or moved within it, from which about 40% have been from other provinces, 3% from other countries and the remaining 57% were related to urban or rural transfers within the province. Study of inter-province migrations in Isfahan Province shows that this province has change from a migrant-sender to a migrant-receiver province due to high industrial, commercial, cultural and service potentials. The share of different cities from these migrations have not been equal, and the growth rate of some of them has reached 19.5% (Shahin Shahr).In this paper, using historical and analytical methods, the author has examined demographic transfer in Isfahan Province in the past as inter-province, outward and inward movements in connection with economic, social, political and cultural factors that affect them, and has investigated the positive and negative economic and social effects of these transfers on both migrant-receiving and sending areas of the province.Finally, courses of actions have been proposed to urban and demographic planners of the province for prevention of unbridled urban migration, control of the phenomenon of migration and organization of urban and rural demographic movements.
