نشریه اطلاعات جغرافیایی (سپهر)
پیاپی 74 (تابستان 1389)

The environmental quality of the city is a dynamic and multifaceted conception that addresses the possible natural and human factors in different spatial scales. Satellite information is the only suitable source of information in order to achieve the continuous dynamic characteristics of urban environments in cities. However, until recently, satellite sensors were not able to record and display details of urban areas. Since urban information systems require high resolution data, aerial photography has been used as standard image input. In any case, the invention of new satellites with multi-spectral and high-resolution sensors (1 meter or less for Quick Bird, Ikonos satellites) and digital aerial scanners with excellent geometric characteristics and appropriate spatial resolution in scale of centimeters, has challenged the technology of analog aerial photography. High-resolution multispectral sensors and digital photographs, along with the location and coordinate data of the global positioning system and automatic navigation systems, create the conditions for updating the database of GIS. Another source of three-dimensional information for modeling is the sensors with laser scans that produce relatively accurate, high-quality altitude information. The paper focuses on the process of the development, the description of spectral combination techniques and the specifications of the images in order to properly assess the urban quality and environment.

The durability, stability and dynamism of each school of thought depend on various factors. One of the most important of these factors is the behavior of followers and believers of that school. In a more clear sense, the actions of followers of a school have a great influence on the dynamism and stability of that school. From the very beginning, the school of Islam has brought light to its followers, and with the emphasis on elements such as reflection and contemplation on the universe and the search for knowledge and research in their characteristics, leads Muslims in particular and the world generally to the creation of utopia. Hence, the role of believers in Islam in the spreading of the teachings and patterns of this religion is crucial for establishing peace and tranquility and in desire for knowledge and research.
The Islamic Republic of Iran, thanks to the achievements and blessings of its idealistic and Islamic revolution and gaining political, epistemological and cultural independence, has taken steps as the pioneer in the revival of the unity and convergence between the Muslim nations, and, in this way, has not avoided great efforts and sacrifices. Based on the contemplation concerning the grounds of unity,
convergence and alignment is one of the most important perspectives of the country.
Based on the doctrines of politics and international relations, the most important professional concern of statesmen and policymakers is how to provide the ground for increasing power and wealth. From the perspective of realistic methodology, today, the increase in the wealth and power of the state-nations is influenced by many independent variables. The most important of these variables in the field of foreign affairs of governments is to create convergence and unity among countries with common goals and values.

Tourism is an industry which currently has a large share of the world's economic activities. In addition to earnings, the industry is a job-creating industry that will provide around forty-three percent of the world's employment in 2010, and in ten years will provide around 220 million job opportunities for different countries.

Drought is one of the most important natural hazards that works in a slow and creeping way. This phenomenon is due to climatic processes, and its severity and frequency depend to a certain extent on the geographical position of the site, which happens every few years as a result of falling precipitation. In order to study and assess the droughts and wet years of Khoy station, the precipitation data of 32 years (1976-2007) were analyzed using standard distribution index and SPSS and Excel software, and it was found that the most severe drought in Khoy station has been in 1995 with an SPI coefficient of more than -1.6, and in 2001 with an SPI coefficient of more than -1.4, while its highest rate of wet year has happened in 1982 with an SPI coefficient of more than 2.8.
Of noteworthy points about the continuity and sequence of droughts is the occurrence of severe droughts during the years 1995-2001 with varying degrees in this station. In order to predict the climatic condition of the Khoy station in the long run, the Markov chain model was used, which suggested that the probability of droughts was 43% and the probability of occurrence of wet years was 42.7%. In other cases, meaning 14.3% of the time, the normal condition of precipitation is prevailing. Similarly, the likelihood of droughts in the long run in winter, spring and autumn was estimated 41.8, 30.5 and 57.3 per cent, respectively

The limitations of the sources and documents related to the field of space in the country necessitates the clarification of the status of space in the development of the country and sustainable security, which, while expressing the fundamental issues concerning space technology and space activities of the country, examine specialized fields in remote sensing and space imaging. Space structure, space legal regime, space functions and space technology are the major topics discussed in this paper.

Developing a regional network strategy to build city-village interactions is a guide for further research on providing an appropriate policy with an emphasis on Indonesia. In this paper, we try to solve the problem of chronic non-communication between rural and urban development theories and plans by introducing a regional network strategy that considers the existing analyses of the issues of continuity and interdependence between villages and cities. To illustrate this strategy a number of examples concerning Indonesian regional conditions are presented.

The rapid expansion of urbanization and the disproportionate physical development of Tehran metropolis due to the increasing growth of population in recent decades has damaged many of the recreational and tourist areas of old Tehran. The existence of those regions could play an important role in reducing mental and emotional pressures of urban life in the present age. This has led to the emergence of high-rise buildings, the density and compression of the living space of Tehran's citizens and the decline in the amount of per capita allocations to green space and recreational use, due to the shortage and high prices of land. It seems that one of the ways out of the current situation and of compensation for the lack of per capita allocations to green space uses is the empowerment of the tourism industry with utilization of unused and immediate areas around Tehran, such as the tourist site of Rudbar-e-Ghasran in the city of Shemiranat with its natural attractions, activating of which, through removing constraints and enhancing capabilities, will play a major role in reducing the issues of Tehran metropolitan area and creating sustainable development of the studied area.

Geography, as a cross-disciplinary science, has greatly benefited from the social and philosophical sciences during its evolution. Functionalism is one of the influential ideas in geography and especially in urban planning as one of the subcategories of this science. In this study, considering functionalism as an essential activity for social life, we have dealt with the key elements of this theory that helped to the life and survival of city. After studying the history and concepts of this theory and its relation with geography based on evidence and secondary documents, we have examined the position of this theory in the urban system and urban planning. What can be said as the result is as follows: The validity of this theory in geography has been most accepted during the period 1920-1960 as the peak and flourishing period of its application after the formation of the Charter of Athens and the prevalence of comprehensive planning. The period from 1960s onwards has been the period of decline and inefficiency of the theory due to the prevalence of a systematic approach and the strategic structural patterns.

From the perspective of human geography, the study of the evolution and demographic analysis of the city of Bumusa in relation to the direct role of the state as a key and influential factor in this paper has been taken into consideration. Methods and indicators used to calculate population analysis have been used. Among the influential demographic indices, immigration has a very important and decisive role, so that from the population of 3052 people in the city of Bumusa in 2006, about 2,228 have been immigrants entered over the past 10 years. Furthermore, the gender ratio of the population of the city of Bomuse in 2006 was 289 men in relation to 100 women due to the migration of men.

A general overview of the process of changes in the country's rural population shows that in the year 1956, about 69 percent of the country's population was in rural areas and 31 percent in the cities. This proportion has faced with decreasing share of rural population and increasing share of urban population during the past years, so that it has reached 38 percent of the rural population and 62 percent of the urban population in the year 1996.
This article tries to investigate the trend of changes in the number of population and settlements in Aradan district located in Garmsar city of Semnan province during the years 1966-2006. The research methodology is a descriptive-analytical method based on field and secondary methods. The results show that between 1966-76 popuation has grown in 15% of Aradan villages, 71.91% were faced with population decline and only 1% of villages had constant growth. In the years 1976 to 1986, the percentage of villages with increasing growth rates decreased compared to previous decade, from 26.31% to 20.37%. In contrast, the percentage of villages with negative growth has decreased from 71.91% to 51.84%. The survey on the growth status of Aradan villages between 1986 and 1996 showed that the percentage of villages that have an incremental growth rate in this period decreased from 20.37% in the 1976-1986 to 9.09%. By contrast, the villages with negative growth have increased from 51.84% to 54.43%. In the period 1996-2006, the percentage of positive growth of villages increased from 9.09% to 19.64% and the negative growth rate decreased from 54.43% to 48.2%.

Recognition of the country's precipitation regime and its spatial and temporal dispersion can be a better basis for proper planning to deal with damage and reduce the effects of abnormalities of water resources. In the present study, the monthly and annual data of 22 synoptic stations during the statistical period (1986-2005) have been used to determine the time and place indices of precipitation and its changes. (Table 2 shows the geographic position of the stations). The analysis shows that according to the average station precipitation of 20 years old, precipitation in the northwest of Iran is 354 mm, variation coefficient of precipitation 0.26, skewness 0.39 and bezel 0.86 respectively. Studies have shown that rainmaking systems that invade the area create different effects due to the geographic location of the stations.

In recent years the use of aerial laser scanners for determining the topography of water beds has been introduced in the world and has found practical aspect. Depth measurement using laser scanners is a more precise, cost- efficient, and faster method than other depth-measuring methods, which is based on accurate measurement of the travel time of two light signals transmitted to the surface and bed of water. Consequently, the use of appropriate hardware and software, in which the source of the major errors is detected and minimized, is very effective on the result of the flight. This paper presents a variety of depth-measuring laser scanners, various techniques used in each of them, and a description of how depth-measuring operations are performed. In addition to expressing the natural causes of error as well as noise causes in operational data, an algorithm for data correction and a method for noise cancellation is presented.

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.

One of the basic and most fundamental factors in the structure of the planet is the climate. There is no doubt that humans, living things and manifestations of life on the Earth are affected by climatic conditions and atmospheric phenomena. Inappropriate distribution of dry land and water, different latitudes, passage of atmospheric systems, heights and elevations covered by snow and ice, dry desert without water and grass, forests covered by trees,... In different regions of the planet, has created different climatic conditions, in such a way that in the broad geography of the world, atmospheric and hydrological hazards such as floods, storms, thunder and lightning, fatal cold, overwhelming heat, etc., annihilate thousands of humans and living organisms annually, or bring about many financial and environmental losses. In this regard, today's civilized human is releasing into the atmosphere millions of tons of carbon dioxide and toxic pollutants annually in order to gain industrial agriculture, so that greenhouse gases have formed a dark blanket on the ozone layer, and this harsh and fatal contamination has seriously threatened the lives of humans and living beings. Therefore, today's violent climate and humans have caused climatic changes in micro and macro climatic levels. Therefore, it is desirable and imperative to identify and investigate climatic changes and to prepare research plans in order to overcome the hydrological atmospheric hazards and to reduce and control pollution and human industrial toxicants.

The paths of three urban amusement parks in different locations in Istanbul were evaluated by students of the University of Istanbul in three separate sites for examination of security, landscape quality, or both. The purpose of this study is to determine the level of personal safety in urban recreational parks and indicates whether there is a sufficient assurance through useful studies of using such a judgment in recognizing the effect of the feeling of safety in the park's designed areas to see the relationship between the sense of safety and the appearance and visual charms of the urban parks? The results of the research show that there is a strong relationship between visible parts, aesthetics and observed security in the three studied parks. Other research findings show that there is a weak correlation between visible safety and beauty.