نشریه اطلاعات جغرافیایی (سپهر)
پیاپی 63 (پاییز 1386)

The spatial pattern is of great importance for the Earth sciences. The spatial pattern enables us to compare the observational characteristics of phenomena and to clarify their spatial relationship, correlation and distribution in terms of geological conditions and processes that have shaped them. Digital cartography and spatial model provide computer support for the observation of phenomena and characteristics in their spatial texture. Transitions make it possible that phenomena have movement and shape in order to gain better visualization and analysis. Space statistics have the ability to numerically determine the configuration for the purpose of form and structure analysis.

Urbanization is considered as one of the main causes of formation of tourism. The evolution and concentration of cities has created certain predicaments and constraints for its inhabitants, and continuation of such a process makes people look for an escape to free themselves for some time from the troubles of urban life, and spend some time on entertainment and recreation and renew their exhausted energy. Residents of cities have been forced to make decisions on spending their free time for various reasons, including physical and spatial uniformity of cities, their heterogeneous and unnatural texture, as well as various types of mental disturbances and stresses and environmental and noise pollution. After the eighteenth century and the Industrial Revolution, a great transformation in the growth, development and emergence of cities arose and various factors such as the transformation of transportation and the speed of exchanges, the emergence of specialization and division of labor, progress in medical sciences and hygiene, and as a result the increase of the population combined with decrease in mortality, expanding immigration, development and concentration of industry and commerce, as well as rising level of income, diversity of businesses, emergence and expansion of mass communication and ... led to the expansion of urban settlement. Subsequently, huge changes occurred in social, economic, environmental and occupational systems, mental stresses increased, noise contamination, neurological disturbances, unruly behaviors and conditions and … appeared. Following the disclosure of the negative aspects of urban life, leisure planning was at the forefront of urban priorities, which led to the birth of tourism and globe-trotting. Tourism (or globe-trotting) is a phenomenon that has existed with its particular forms in human societies from time immemorial, and has gradually evolved along with historical developments to the present age. This phenomenon is generally based on travel and displacement, which is itself the result of various mental, cultural, social and economic needs of mankind. Subsequently, huge changes occurred in social, economic, environmental and occupational systems, mental stresses increased, noise contamination, neurological disturbances, unruly behaviors and conditions and … appeared. Following the disclosure of the negative aspects of urban life, leisure planning was at the forefront of urban priorities, which led to the birth of tourism and globe-trotting. Tourism (or globe-trotting) is a phenomenon that has existed with its particular forms in human societies from time immemorial, and has gradually evolved along with historical developments to the present age. This phenomenon is generally based on travel and displacement, which is itself the result of various mental, cultural, social and economic needs of mankind.

Recognition and classification of land features on the images have been considered as the base of many applications including the development of a digital model of elevation, identification of changes, updating of maps and many other cases in geomatics. In recent years, researchers have tried to improve the accuracy of this process. By recognizing land features and classification of the image we mean the set of processes and operations which lead to identifying land features and attributing a sticker to each of the pixels entering the classification operation. Based on this, recognition and identification can be achieved by relying on the differences between objects in terms of characteristics recorded by different sensors. The more varied information is available, the more precise and reliable the results will be. Today, with the advancement of technology, various types of information are available by various sensors. But none of these sources provide all the textural, geometric, and spectral properties of an object. That's why it is inevitable to combine the information from different sensors to complete the descriptive space that leads to more accurate extraction of land features. In this study, the integration of digital aerial image information and Lidar data has been evaluated and its role in increasing the accuracy of classification has been tested using a data set from an area in Germany. The results show that the classification accuracy is increased by using digital aerial image and Lidar data simultaneously.

Throughout history and throughout the centuries, humans and other living organisms have adapted to the climate and environmental conditions of their residence. However, existing estimates indicate that the consequences of climate change and its effects on the environment are noteworthy. Atmosphere pollutants, acid rain, etc., affect the habitats of the planet, and sometimes leads to the extinction of biological species. The decrease in the ozone layer and increase in the Ultra Violet rays play effective roles in damage to plants and animals and the development of diseases. In addition to all of these, the factors created by natural disasters caused by atmospheres, such as cyclones of tropical regions, droughts, colds, floods, abnormal monsoons and severe El Ninos also affect the biosphere. Climate change occurs in various forms in natural systems: changes in wet and dry areas, hot and cold areas, increase and acceleration of climatic cycles (monsoons, El Niño, droughts, etc.)…, and this changes in turn lead to changes in the biological cycle, which, although not all of these changes are in a negative direction (such as increasing the plant's yield versus increasing the CO2 content of the atmosphere), it nevertheless disturbs the equilibrium in the ecosystems, which cause chaos in it, such as uncontrolled precipitation that increases weeds that dominate the ecosystem and destroy other species.

In general, the sustainable development of the city is due to the stable, constructive and systematic interaction of man with man (in various dimensions) and man with the environment (in the natural-ecological aspect).Interactions that, over time, make the city environmentally sustainable, economically durable, socially united and physically beautiful. Therefore, the present article aims to demonstrate the fact that the tourist (1) as a smart and human element and as an input of an urban system can have positive effects on the various spatial dimensions and can be a factor contributing to the sustainable development of the city. Furthermore, city and city managers, in mutual connection and in order to provide proper bases for the purpose of maximum enjoyment of the aforementioned advantages, inevitably provide the structures and infrastructures and define appropriate and proportionate functions in the city and its hinterland (2). - Creating an appropriate mentality among people, planners and managers about the role and importance of tourism (3) in sustainable urban development. - Formulating regulations and preparing conductive - comprehensive or structural - strategic plans for cities in accordance with leisure needs of citizens and the spirit of diverse experiences common among tourists. - Finally, ethical and practical commitment of urban managers to provision of financial resources and implementation of tourist projects proposed in approved urban plans and the formation of urban tourism units in municipalities. The triple levels suggested in this paper are proposed with the aim of transforming a perceptual environment (a belief) into a functional environment (objective truth), and with the goal of achieving sustainable development of the city from the perspective of tourism industry.

Undoubtedly, floods are known as one of the most important natural disasters. In practice, the flood is considered to be the most enormous disaster in terms of mortality and financial losses. In a ten-year period in the world (1988-1988), about 390000 people were killed by natural disasters, 58% of which were flood casualties, 26% related to earthquakes, and 16% were caused by storms and other disasters. The related financial losses in this short period were about $ 700 billion, 33% of which caused by flood, 29% by earthquake and 28% were related to the storm. Throughout history, humans have been attracted to the fertile lands that are located on the course of previous floods, and have made their lives easier by settling close to rich sources of water and food in these lands. The same river or water flow that provides people with livelihood will make them more vulnerable to flooding. Flood can be caused by heavy rainfall, accumulation of heavy and abnormal sediment behind dams or dams’ failure, rapid melting of snow, blockage of the course of rivers due to landslides, or explosions of water reservoirs.

Globalization is a term now found in many scientific texts, and practically all scholars have had certain contemplations about it. Undoubtedly, if there are thoughts about achievement of globalization, both desirable and unwanted results of it must be taken into account, and it is certain that a process of this power involves influence and change. The process of globalization on the one hand, and its impacts on cities on the other, indicate the need to pay attention to the interactions of these two, which is vital for cities as the main and most important human settlements. This discourse, along with presenting a brief history of globalization, highlights impacts of this process on cities, and examines the nature of these effects in developed and underdeveloped or developing countries in economic, socio-cultural, environmental and physical terms.

As long as rural development planning is not aligned with other projects of regional planning taking place in rural areas, it can not be very effective, because rural development planning inherently influences the region's economy and its prospects. On the other hand, in the process of planning for rural development, the recognition of the structural characteristics of the levels of development and awareness of the potential and environmental abilities of each region is of great importance. In the present study, using 23 indicators and variables required to recognize rural development, various economic, social and service grounds have been identified and analyzed using Morris model. The results of the study show that there are many differences in levels of development, and if this trend continues, it is necessary to lessen the inequalities through the implementation of useful rural development plans. The result of the research also show that the level of development of rural areas is not homogenous and villages are in a low level in terms of development; therefore, it is desirable that rural development planners focus their attention more on increasing dimensions of development.

Transportation is one of the most important and valuable assets of any country in meeting the needs of the growing population and can be a solid backbone for its economic growth. Lack of foresight and basic and field studies to develop this industry will cause many problems in the development and fulfilment of vital needs of the people of society, and perhaps one of the best and, at the same time, most controversial issues in this regard is the safety issue in designing roads. One of the natural disasters that reduces the safety of roads is the landslide phenomenon. The slippage or thrust of soil masses in sloping lands can be studied under four specific categories: Slidiiy or slippage, Greep or soil crawl, Fall or fall of rock and soil, and Flows or flowing streams on steep lands. Every year this phenomenon causes financial losses and, in some cases, it unfortunately brings about great number of casualties in our country, destroys boundaries of roads, monuments and other infrastructures, and the government is forced to pay enormous amount of money to compensate the devastations and relocate masses of soil. For example, in the earthquake caused by the activation of the Baladeh fault on the May 26, 2004, what caused the destruction of the northern roads near the earthquake’s epicenter, especially the Chalous-Tehran road (Kanduvan route) and, unfortunately, death of twelve people, was the landslide phenomenon that was caused by the earthquake.

The natural disasters that form part of the nature of our environment usually occur so severely that they usually cause many casualties and losses. The ordinary conditions of everyday life of human beings and the social structures and infrastructure of the region suddenly become disrupted and people suffer and are left in distress. As a result, the affected community is at once in serious need of food, clothing, shelter, medical and health care, and protection against adverse environmental factors (Abedi, Ghodratollah, 1998; p. 53). The natural disasters of Iran fall into three categories: A - Climatic disasters like flood - drought - storm - avalanches – extremely cold weather – snowstorm - frost - thunderstorms - severe heat and cold - forest fires (Gilan, Mazandaran, Golestan) - sand storm. B. Dangers from some geological and tectonic processes (earthquake, landslide, debris flow, mud flow). C - Environmental hazards including extension of salt pans, desertification, environmental degradation. According to the scientists’ climatic division, our country is part of the arid and semi-arid climate of the world. One of the characteristics of this type of climate is the imbalanced distribution of precipitation in time and space, so that in one year it suffers from low degree of precipitation, or, in other words, from drought, and in another year it is struck by abnormal and untimely increase of precipitation, and as a result the overflow of seasonal and permanent rivers and consequently formation of flooding, causing extensive damage to agricultural land and urban and rural facilities. In coastal areas of the Caspian Sea, the risk of sea water penetration and the operation of waves are among other natural disasters causing damage to the north of the country (National Committee for Natural Disaster Mitigation; 1998; p. 4). The flood in Gilan province is a major threat from both life loss and economic point of view, and all economic and communication infrastructures including dams, irrigation canals, roads, bridges and other investments in agricultural and non-agricultural sections have been exposed to threat and destruction. In this regard, the objectives of this paper are to identify the causes of flood and its undeniable effects in the region.

Desertification is a major problem of lands that are located in arid areas of the world and consequently gradually destroyed. Elimination of soil and vegetation has adverse effects, as almost 50% of land degrades as a result of human mismanagement of agriculture and rangelands. A large part of North America and Spain are covered by arid areas that have experienced desertification. Excessive grazing of livestock and felling of forest trees tend to increase desertification in rangelands. Agricultural activities that increase the rate of water and wind erosion play the largest role in consuming water for agricultural products, and mismanagement of water resources may cause salinity and therefore reduce water resources’ potential of utilization. In addition to destruction of vegetation, erosion and salinization, the effects of desertification on the fertile Loess soils can be seen as soil compression and shelling. Urbanization, mining and tourism have undesirable effects on different parts of land because these lands are also categorized as rainfed or irrigated agricultural lands. If there are proper financial sources and practical policies, combating the phenomenon of desertification using known techniques can be of consequence.