نشریه اطلاعات جغرافیایی (سپهر)
پیاپی 58 (تابستان 1385)

In this paper, we use the Theory of Information Sciences and its application in the World Wide Web (WWW) in order to study the ways of access to geographic information. The two main information retrieval systems include data and information retrieval. A data retrieval system includes retrieval models, indexing, matching and retrieval, linking, sorting, search time and determining the method of search. The main purpose of information retrieval is to match the needs of users to information within the system. GIS retrieval is a combination of data and information retrieval. The language of search uses signs and natural language, automatic indexing of geographical information and standardization of geographic information. Geographic Information Retrieval Systems (GIRS) can be viewed on the World Wide Web (WWW).

Familiarity with the geographical situation of neighboring countries is essential in different aspects, such as the interaction of geographical factors (human and natural), the relative position of the neighboring states' territories, the type of government and the international and regional obligations, participation in politico-military treaties and dependence on imperialist powers. Other important issues such as: Cultural Commonality; trading conditions and relations; common economic resources; determination of foreign policy goals; recognition of spatial conditions and the strategic importance of threating positions; positions and conditions important for imperialist powers; and other issues such as inclination of the region towards crisis, and the imbalance of the political system which is followed by problems such as the imposition of displaced people in neighboring countries emphasizes the importance of attention to geographic considerations of neighboring countries. In this paper, the importance of the basic role of spatial relations in recognition of the geography of neighboring countries are discussed, with emphasis on position, size, shape and neighborhood.

The collection of ground control points for photogrammetric blocks adjustment is one of the costly and time-consuming parts of photogrammetric surveying, and photogrammetrists have always sought a way to reduce the number of ground control points to the extent possible. Today, the application of GPS data in surveying activities has been widely considered: from acquisition of coordinates of ground control points to the obtainment of the coordinates of image centers and camera justification parameters at the moment of shooting, in Mobile Mapping, cadastral surveying and in combination of GPS data with INS2 data which is currently undergoing extensive research, because it reduces the number of control points. In this study, the precision of adjusted blocks with the help of GPS auxiliary data in the adjustment of the 1:25000 blocks of Iran with independent and bundle adjustment models methods has been examined, and the results of the study show that it gives satisfactory precision on the considered scale for the region of Iran.

One of the most common and important methods for the regulation, presentation and analysis of scientific findings is the use of statistics science. In the science of geography, the use of quantitative statistics and data is considered necessary. It is also evident in various geography disciplines, including urban geography. The purpose of this study was to visualize facts within the data and analyze them on the basis of statistical information. In order to carry out this task, it was attempted to establish a relationship among population, urban utilities and their waste production in SPSS software using statistical analyses. In this regard, two methods of Inter Regression Analysis and Stepwise Regression Analysis were used. The results of the analyzed data showed that the population and urban utilizations in Tehran justify the garbage produced in different regions in terms of volume, size and shape.

In this research, in order to investigate the frosts occurred at Ekbatan station (Hamedan), the minimum daily temperatures of this station were studied. In general, the frosts were divided into three weak (mild), moderate, and severe categories. Next, the range of changes in the time of occurrence of these frosts was determined and the frequency of their occurrence was calculated. It was also attempted to obtain an experimental formula for the first autumn frost in a particular year based on the date of the last frosts of the spring of that year, and to determine the probability of occurrence of temperature thresholds between 0 and -15 ° C in different months of year by calculating different statistical parameters. In addition, it has been tried by dividing the the year into 36 distinct decades (ten days) to calculate the temperatures that are possible to occur with different percentages of probability.

The technology of hydrographic Side Scan Sonar has been developed by Professor Harold Edgerton and his colleagues in the year 1960. A Side Scan Sonar is a device that has the ability to search the space around it. The Sonar can be compared with a radar, but in a sonar the reflection of sound waves is used, unlike radar which uses electromagnetic pulses. Sound pulses usually range between 100 and 500 kHz. The frequencies higher than this magnitude have lower ranges, although they increase the accuracy and resolution.

Postmodernism has been interpreted as a broader concept than modernity, and it is the offspring of modernism. The era of modernism, which was based on trust to human intellect and did not accept a world beyond reason, was influenced by philosophers such as Hegel, Kant, Rene Descartes, and before that, Francis Bacon, which caused profound changes in various areas of human life, and perhaps it was only in this period that mankind reached full self-confidence and considered itself to be ruler over its own destiny. But modernism, as it originally seemed to have succeeded, had major effects on crises such as the first and second World Wars and the racial, gender and environmental crises in the twentieth century. These factors led the philosophers and thinkers of the second half of the 20th century to doubt the wisdom of pure reason, and those like Karl Raymond Popper believe that rationalism must itself be criticized. Therefore, a period in the name of postmodernism has come to the fore which has had profound effects in various scientific and artistic fields. In this paper, we have tried to understand the concepts and definitions of modernism and postmodernism to the extent possible, and to analyze the similarities and differences between them and the impacts that each period have had on different urban areas, both physical and non-physical.

Tourism is a process that has long existed in its certain forms in human societies, and has gradually evolved through historical periods. This phenomenon is generally based on the main factor of travel and movement, which itself is a result of various psychological, cultural, social and economic needs of man. Over the past years, world-wide tourism and international travel were considered as luxurious even for those who enjoyed high financial power, and were considered as being done merely for fun and entertainment, while today the tourism industry is one of the world's largest industries. Today, in most countries of the world, especially developing countries, in spite of past mistakes and implementation of inappropriate policies in the tourism industry which have led to enormous social and environmental costs, the development and prosperity of this industry is becoming increasingly important, and new trainings and strategies have started to provide inexpensive continental tours which have many enthusiasts (Razavi, 1995). An extraordinary increase in travel to attractive destinations with the goal of optimal use of leisure time has created special infrastructures and facilities and job opportunities for local people in tourist areas. Thus, over time, the tourism industry has been highly regarded by developed and developing countries, because tourism development, especially the increase in the number of international tourists, will boost a wide range of economic activities of the host country or region. Of course, the development of tourism industry is of paramount importance for developing countries, which are faced with such problems as high unemployment, limited foreign exchange reserves and single-product economy (Jame’ii, 1995). In this paper, we try to analyze the role of the tourism industry in rural development. So far, the most attention has been paid to urban areas and natural and cultural attractions. Therefore, considering the importance of rural tourism and the role it plays in rural development is of major importance.

Considering the importance of the Caspian Sea in terms of its unique characteristics and the role it plays in the economic life of the Commonwealth Countries, it is important to act conscientiously and with foresight in relation to control and prevention of any crises (pollution, fisheries, sea water fluctuations, legal system of the sea, etc.). The southern shores of the Caspian Sea are in more desirable conditions in terms of developmental requirements due to the geographical location and topographical condition of the region, and it is hoped that the above-mentioned goals will be achieved through proper management and planning. In this collection, after introducing the Caspian Sea, its unique characteristics have been described and the issues surrounding it have been studied, and finally solutions have been suggested in relation to these issues

New and accurate information can help decision makers in planning and controlling the normal situation. This type of dynamic information is of more importance for emergency and responsive planning. The data gathered in hours, days, months, and years after an unfortunate incident can improve policies and practices to reduce risks and increase the effectiveness of emergency planning, awareness, preparation and search. Earthquake is one of the oldest enemies of man which today can be represented and analyzed. The Geographic Information System (GIS) is used to analyze the population and infrastructure positions. This paper, describing a study on the preparedness of a section of Istanbul (Turkey) against the earthquake, shows how to it is possible to minimize the effects of earthquakes by using GIS, plan emergency response and prepare a list of urban information.

Urban landscape creates a certain local climate that distinguishes it from the rural landscape around it. This is confirmed by the presence of a thermal island and by studies that show that over a quiet and clear-sky night the temperature of the city and that of the village differ above 12 degrees of Celsius. Different land uses in the city create a mosaic of hot and cold areas. For example, there can be a difference of more than 7 degrees of Celsius between a park and a building environment. The geometric state of the streets is important in thermal pattern of cities.

The Caspian Sea is the largest closed lake in the world located in one of the most strategic energy production areas in the world. This sea is of great importance for the countries of the region in terms of management and legal issues due to its vast oil and gas resources, communication and commercial water lines, marine products, as well as environmental conditions, ecological balance, preservation of the environment and creation of beautiful tourist and natural landscapes in surrounding regions. Since the collapse of the Soviet Union, the four Treaties of the years 1921, 1931, 1935 and 1940 had established a solid legal framework between Iran and the Soviet Union, based on principles such as equality, monopoly, non-military identity of the sea, cooperation and ... However, after the collapse of the Soviet Union and the emergence of the issue of succession in that country and the formation of new states of Turkmenistan, Kazakhstan and Azerbaijan, legal problems have occurred and the policy of some of these newly independent states regarding the sea have raised doubts about the legal status of the Caspian Sea which can bring about undesirable political and economic consequences. The author, after referring to the legal status of this sea, has analyzed the problems created in its legal regime after the collapse of the Soviet Union using analytical and documentary methods, with conclusion that the existence of a valid, clear and firm legal regime based on previous (existing) treaties, while resolving the existing problems, will strengthen the sovereignty of Iran over the part of the sea in its vicinity.

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.