نشریه اطلاعات جغرافیایی (سپهر)
پیاپی 56 (زمستان 1384)

Based on initial architecture, the World Wide Web is a collection of human knowledge that allows users to exchange ideas and suggestions among distant places. Cartography and Geographic Information Systems (GIS) are in the early stages of development, considering the characteristics of spatial and geographical information. Currently, the Web provides access to various forms of land features’ information in the form of maps, aerial and satellite imagery, sound and text, so that they can be linked to other related information. The World Wide Web is also designed to connect any land feature’s information to that of other land features. As a result, the Web has the potential for ease of change in cartography and GIS through three basic mechanisms: 1 - By increasing its application in mapping and GIS and providing greater access to tools and data, 2. By combining non-spatial information technology, GIS and production of combined maps (spatial and non-spatial), and 3. By establishing a virtual world and testing models and visualization that should be designed, analyzed and interpretable.

All the universe apart from the objects and phenomena within it is called Space. The Earth, atmosphere, celestial bodies, the Milky Way and other galaxies are within space. Many physicists have divided space into two parts: (A) The near space that lies within a distance of eighty kilometers from the Earth and stretches to areas near the moon's surface. The space around the Earth is called the inner space, which is a complex region, and the physical characteristics, effective geographic factors and points of interest in the space military planning were presented through the last three papers (parts nineteen, twenty and twenty one) under the following three categories: - Intermediate levels of air – space; - Near space or environmental space of the earth; - The moon and the space around it. (B) The outer space or the distant space which is extremely vast and in which planets and moons move, and which the Earth has no effects on. The outer space sometimes extends to the space between galaxies. In this paper, the outer (distant) space has been of interest, which is very distinct from the near space. Coverage of outer (distant) space is very wide and there are vast opportunities for maneuvering. Here, some discussions on how to select the orbit and the position in space as well as the performance of different weapons are presented.

Decrease in production capacity of soils is one of the problems in the country. This decrease is affected by factors such as soil erosion, especially surface erosion. Exit of more than 2 billion tons of sediment per year from the watersheds of the country shows the depth of the disaster. Among other factors that play a major role in reducing the fertility of soils is the salinity of land. This phenomenon occurs in natural resources (low lands) and agricultural lands (inappropriate drainage and improper management). Preparation of soil salinity map is one of the first steps in identifying these areas. There are several methods that can be used to achieve this goal. One of these methods is the application of satellite imagery and spectral reflections in order to provide a map of salinity in different regions of the country, because these images are completely new and up-to-date and display the latest changes on the Earth's surface. In this paper, which is the result of implementation of research project, the application of satellite imagery in preparation of Qazvin plain salinity map using satellite images of Landsat ETM in 2000 and Landsat TM in 1987 in a spectrophotometric manner was investigated. Comparison of the obtained results with experimental data of soil samples and field observations confirms the high accuracy (83.3%) of the prepared Qazvin salinity map by the spectral method.

The rotation of the Earth along with its transitional movement around the sun, leads to the appearance of night and day and creation of different seasons throughout the year. On the other hand, the inclination of the axis of the Earth and its unsteady speed in the transitional movement around the sun create certain changes in the religiously important times throughout the year which have been examined along with the temporal and spatial factors that cause them in the two cities of Tehran and Shiraz. In view of the importance of the issue for Muslims who are bound to perform prayers at the first true legal time, the results of these changes can be used to clarify the public's mind and to motivate the related fields’ enthusiasts to pay more attention to the astronomy and geographic issues.

The trajectories are presented that suggest the sequence of incidents involving in the formation of Loess deposits, which include both the hypothetical deposits and the deposits of central China, Hungary, Nigeria and Tunisia. These trajectories describe the potential role and interrelationship between different types of silt production mechanisms in the formation of Loess. In application of these trajectories the desert Loess is a point of interest, and the result depends on how the terms "glacial Loess" and "desert Loess" are used. If the desert Loess is to be interpreted as silt production mechanisms, or to determine the environment in which the “wind-blown” has occurred, then the Loess desert is fully real and widely scattered. But if the term glacial Loess is used to attribute silt production to the global climate regime under which the Loess deposits are formed, instead of the responsible geomorphic mechanisms, the desert Loess can not be a suitable term for classification of Loess deposits. It is suggested that the classification of Loess deposits be carried out according to the global climate regime under which the Loess are accumulated, as it will make it easier to understand the environmental conditions at all stages of the formation of Loess deposits.

employment and social situations equal with men, has gradually changed conditions in favor of women. Now women are demanding a larger share of the employment market, and they have achieved significant economic positions in, for example, the emerging electronic industries of newly industrialized Asian countries. While in China the sex ratio at the first birth is close to 1, but at next childbirths the proportion of male babies increases, the phenomenon which can be observed in South Korea and Taiwan as well. New techniques for determining gender, an important issue in the Chinese society, include the use of the amniocentesis method in Korea and Taiwan and ultrasound waves in China. The result of the shortage of female babies will lead to the creation in these societies of the largest group of single men in the world unable to get married. According to the latest predictions, by 2020 the number of Chinese single men will be more than the total female population of Taiwan. In addition, an increase in the surplus of male population in China is likely to result, in some areas including Shanghai, in a sharp drop in fertility rates, even to levels under the substitution line.

The nomadic society of the country, affected by the upcoming conditions, has in its historical course experienced processes of settlement, one of its prominent characteristics depending on the effective mechanism of stability or lack of stability. The purposeful study of these trends can familiarize experts with the systematic structure of the nomadic community which, with its dynamic and flexible ability, has been able to pass various stages of transformation, and help them guide the system for the sustainable development of the nomadic tribal community, providing an illustrating guide to understand the future of plans related to nomadic society, as ignorance of this fact will lead to expenditure of financial sources on irrelevant causes and waste of expert forces’ efforts. Accordingly, those nomadic settlements that are spontaneously adapted to the summer, winter, and middle residences formed the most accepted form of settlement in order to reach a reasonable dispersion of the population in the land to make optimal use of resources in the varied expanses of the area and embody the full adaptation of sustainable settlement. In this way, identifying the spontaneous nomadic settlement areas can act as a reliable point of reference for integrating and uniting the settlement plans of the relevant organizations with the inner will of the nomads and an appropriate setting for a sustainable and dynamic settlement; if these plans are organized according to the time requirements will lead to purposeful and active ‘’sedimentation’’ of the nomadic. Based on this, recognizing these regions as a stage in the dynamism and systemic evolution of the nomadic community leads us to a correct understanding of the "dynamic system" that has passed many historical developments with proper performances, and makes the efficient management of current developments of this system possible.

The planet is becoming a world of cities, as the twentieth century witnessed a remarkable development of cities, both in terms of numbers and size (Scoru, 1993). At the beginning of the nineteenth century, about three percent of the world's population lived in urban areas. At the beginning of the 20th century, this number reached about 15%, reaching 46% in the late 20th century. In 2000, this increased to 48.2%. Studies show that in 2025, it will reach 62.5%. On this basis, about two thirds of the world's population will by then live in cities (Bradshaw, 1987) A look at the trend of population growth in developing countries is far more worrying than the whole world. For example, in 1960, the share of these countries in the number of metropolitan cities in the world was 9 out of 19 urban areas, while in 2000, this number reached 50 metropolitan areas out of a total of 66 mother cities (Lo, Fu-Chen 2001). However, there are many differences between the third world and the whole world (in particular in developed countries) in terms of the factors that make up urbanization and the consequences this process brings about (Roberts, 1978). The differences in levels of urbanization and growth rate in these two systems reveal the differences in the socioeconomic systems that are rooted in historical, cultural and other processes. In wealthy countries, urban structures are clearly defined. Population growth is minimal and urban migration process is negligible. But for a developing country, applying this city vision and optimistic assessment will be misleading. As it was stated, the earth was for tens of thousands of years empty of any building made by human hands. These settlements gradually became more compact, turned into villages and then towns. Since the last few centuries, cities have become very complex human settlements. Despite the fact that the city has a relatively long history, but widespread urbanization has a history shorter than 200 years.

In this paper, the concept of Thermal Island has been discussed in general. First of all, the definition of the city’s thermal island and its history have been presented using illustrations and diagrams. Next, the climate variables affecting thermal islands have been considered. The purpose of the research is to introduce the city’s thermal island or the point of maximum of heat in the city, which mostly includes the city center. The term “thermal island” refers to the fact that city is warmer than its suburbs and surrounding area, which in some cases can show in a difference in temperature of 5-8 ° C. The research method in the paper is documentary, secondary and with the help of utilization of electronic sources and various websites. In addition, the hypothetical factors that create the cap layer covering the city’s thermal island are mentioned, and the radiation level in the urban area, its comparison with the suburbs and the effects it has on human health and the environment have been studied. Finally, strategies for dealing with Thermal Island through improving public behavior in relation to protecting the environment, developing green space, etc. have been examined and proposed.

The mid-Holocene coasts have radical differences with the early and late Holocene coasts both in terms of process and form. To understand this difference, this paper has compiled the calculations in recent studies of sea level changes and coastal evolution between 7800 to 4400 years ago. (Approximately 7000-4000 years ago, measured by carbon 14). The average sea water level during this period has basically changed by increase in water drainage due to the melting of ice planes at the northern hemisphere, while the role of Antarctica in this change is insignificant. This paper deals with the eustatic changes in the mid-Holocene, namely, the study of age-height and then patterns of coastal development.

In order to prevent, counteract and reduce the effects of natural disasters such as earthquakes, we have to deal, in addition to technical matters, with crisis management and planning how to deal with crises caused by natural disasters. If the probable problems arising from the crisis are not foreseen, the cost of reconstruction and repair of damages by the crisis will be very high. Crises caused by natural disasters will have significant socio-mental and economic effects on society. Therefore, recognizing the principles of proper methods of disaster management can be effective in preventing the occurrence or reduction of the negative effects of these incidents and preventing them from becoming social, economic and environmental crises. Therefore, the availability of proper management plans in times of crisis will, on the one hand, strengthen the foundations of society in all fields and, on the other, significantly decrease the amount of financial and life damages and prevent social, economic and environmental collapse.

Today, the most important weaponry in developed countries are utilized based on information technology. Since the coming into existence of human beings, gaining information about the enemy's forces have played a very important role in achieving victory in wars. Furthermore, obtaining, interpreting and processing information is of special importance in systematic decision making. At this point in time, production, transformation, transmission and management of information is not only very sensitive and important, but also highly complex and difficult. The Persian Gulf War was in fact a war of the enemies’ technologies against each other. Sometimes there is no need to fight physically, but the fight is practiced by the use of technology, as in some cases the battle ends within a short time due to the availability of information technology. One of the most important tactics of combat is the intelligence (and counter-intelligence) operations of the forces which must be timely, prompt, accurate, interpretable and descriptive, because it plays a vital role in success in a battle. This has been proved in case of the coalition forces in the Iraq War. Modern weapon systems will be able to anticipate the time of attack and provide forces with details of highest accuracy. This results in a victory against the enemy with a lower cost, which indicates the importance of proper and correct spatial information and the extent to which they are used to plan and command combat operations.