نشریه اطلاعات جغرافیایی (سپهر)
پیاپی 82 (تابستان 1391)

Imageries received from aerial hyperspectral or satellite sensors record reflected data from earth surface in more than a hundred spectral bands. Hyperspectral imageries are used in different applications and different methods have been proposed and developed to extract data from these imageries. Diagnosing inconspicuous features or anomaly detecting is one of the most important methods in extracting data from hyperspectral imageries.
The basic idea in designing hyperspectral sensors is based on the response each element shows in different sections of electromagnetic spectrum. Each element shows a specific reflective response in different sections of electromagnetic spectrum based on its own molecular structure. Different elements and materials show unique reflective response in similar situations.
Hyperspectral imageries have diverse and varied applications, among which we can refer to environmental monitoring, agricultural application, identifying unexpected events, geology, mines exploration and urban and regional studies.

It is possible to call tourism as the “White Industry” because in contrast to most manufacturing industries it provide the necessary prerequisites for friendship and mutual understanding between different nations and bring peace for people without polluting the environment. Industry is a revenue and a source of employment in national level. Tourism is an appropriate alternative and a development strategy, especially when other economic sections are making less profit. Thus, coping with low levels of income and providing new opportunities for employment and social changes are the principle reasons for the development of tourism which can provide new hopes for decreasing poverty especially in areas facing economic depression. Some advantages of this industry includes employment, bringing cash to the country, regional interaction, aiding global peace, helping investment in cultural heritage, improving the environment, improving wild life habitat, developing rural regions with tourism attractions and preventing emigration. The present article explains obstacles and negative effects of tourism and then applies descriptive-analytic method to explain society-based tourism as a solution.

In order to investigate synoptic-dynamic situations which results in thunder storms in South Western parts of the country, data were exploited from 16 synoptic stations in South West of Iran during a 10 year statistical period (1996-2005). Fitting the precipitation data, six types of severe storms were identified. Exploring the exploited systems, two general patterns were identified for thunder storms with severe precipitation. The first pattern follows integrated systems pattern, so a ridge from North West Africa to Scandinavia causes cold weather falling on the Mediterranean Sea and deepens the Mediterranean trough, which in turn strengthen the East Mediterranean low altitude center. Continuous cold weather falling on this cyclone center increase pressure gradient in east Mediterranean area and makes penetration of 500 hecto Pascal trough toward middle Red Sea possible. Increased temperature gradient over North Africa and the Red Sea strengthen Sudanese system and while moving toward North of this system integrates with low pressure Mediterranean system and results in unsustainability in West and South West Iran. The Second pattern is a low pressure Sudanese one. Low pressure Scandinavian system result in cold weather of pole neighboring latitudes falling into lower latitudes. Azore anticyclone which is formed over North Africa transfers cold weather to North Africa, aggravates unsustainability, strengthen Sudanese system and creates a weather front. Thunder storms require access to hot and humid weather which is injected into the area due to the proximity of Southern seas.

The present article proposes land transformation model which consists of Geographic Information System (GIS) and Artificial Neural Networks (ANNs). This model applies varied political, social and environmental models as predictive variables. The study introduces a version of LTM model for Grand Traverse basin in Michigan gulf and shows how factors like roads, highways, and local streets, and rivers, coastlines in large lakes, entertainment facilities, inland lakes, agriculture density and landscape quality can affect urbanization pattern in coastal basin. GIS is used for understanding local patterns of development, estimating predicting capacity of the model from artificial neural network, spatial expansion of predicting stimulators, and spatial analysis. Finally, the contribution of each predicting variable is estimated and presented on a spatial scale. Landscape quality was the strongest predicting variable on the smallest scale. Multi-scale impacts of land use changes are analyzed using the relational impacts of the site (like landscape quality, local streets) and position (like highways and roads between different regions) on different scales.

The present article aims to investigate causes of flooding in Esfarayen County and introduces different applications of geomorphology in providing structural methods of floodwater management. Considering the present situation, structural methods like canals, bridges and retarding reservoirs are used for introducing flood controlling methods. In order to design these structures, maximum annual instant discharge was calculated using Dakin equation and statistics received from Bidvaz River hydrological station. Then, sections of the buildings and their dimensions were determined for a return period of 5 to 500 years using Manning relation and finally discharge was calculated by multiplying average current velocity to section area. Results indicate that apart from natural factors like precipitation regime, impermeability of formations, drainage density, vegetation poverty and slope, human factors like settlement and development of villages across fans, redirection and integration of waterways, unnecessary arches in canals and ignoring probable maximum precipitation in construction intensify flooding in villages. According to the findings, any changes to the dimensions, types and forms of drainage network must be in accordance with geomorphological theories. Moreover, this subfield of physical geography is especially potential in proposing structural methods for floodwater management.

Rural environments are a part of human society. Sustainable and integrated national development depends on sustainable development in regional, urban and rural level. In this regard, the second, third and fourth economic, social and cultural development plan introduces rural construction as one of its goals and considers issuing residential ownership document as an executive solution. Since ground is the main context of material wealth and treasures. Moreover, it is economically valuable and has different applications in satisfying needs of human society (like construction). Accordingly, rural houses and buildings are among capital interests of rural societies and their owners need to feel secure in regard to their possessions. On the other hand, the need for ground-related information as a basis for development and control of ground resources results in the priority of document issuance for each building.
The present article investigates the historical trend of issuing documents and especially developmental programs in Iran after the revolution.

Change detection is the process of identifying changes in an object or phenomenon by observing it in different time intervals. Careful and timely detection of changes in land forms and reliefs provides a better basis for understanding relations and the interactions between human and natural phenomena. In this way, it makes managing and exploiting resources possible. Remote sensing data is a wonderful resource for different applications in detecting changes, due to its temporal magnification, spectral and radiometric variety, appropriate digital format and integrated view. Many methods have been developed to detect changes, all of which have advantages and disadvantages. According to the studies, these methods show different results in the same environment. Generally, change detection methods are classified into 3 different classes: pre-classification comparison, post- classification comparison, advanced methods. The present article analyzes some of these methods like image subtraction, image division, main components analysis, detection of controlled changes, and detection of uncontrolled changes, hybrid, artificial neural networks, vegetation-impermeable surfaces-soil model and geographic information systems. Pre-classification methods detect changes caused by multi-temporal data without producing classified vegetation and land-use maps. Yet, post-classification methods provide a precise matrix of changes and they usually need input analysis. There are diverse advanced methods which are usually developed in response to specific studies. Studies indicate that image subtraction, main components analysis and post-classification methods are the most popular methods used for change detection. However in recent years, artificial neural networks and combinations of remote sensing and geographic information systems are regarded as important techniques.

The idea of healthy city is an idealistic plan. Although the plan is not more than a few years old, yet its historical roots are very long and vicissitudinous. In fact, 1984 was a turning point in which endeavors of people like professor Dehel, Dr. Eshton and immense supports of World Health Organizations led into introducing and sometimes enforcement of new patterns and policies so that now after more than two decades the idea of healthy city has turned into a global movement.
After the Industrial Revolution, different changes in cities resulted in many problems and issues entangling cities. Therefore, cities faced numerous problems like population explosion, growing growth density, limited housing, poverty problems, breakdown of the city - nature relation, air and noise pollution, unhealthy slums, decrease in healthy level of social life and etc. According to WHO predictions, by 2005 more than 60 percent of the world population will be among urbanites. This urban population will intensify the present problems. Since cities are alive, dynamic and human-centered, planning a healthy city based on its standards and principles is necessary in long term. The present descriptive-analytic article seeks to understand standards and principles of healthy city.

The present article shortly introduces Bazoft basin   (one of Karun subbasins) and discusses different methods of predicting flood discharges, all of which requires specific local data. Due to lack of statistics in most basins and subbasins of the country, the suggested solutions require less hydrological statistics. Flood modelling is one of these solutions which requires fixed physiographic data and can be used for estimating and evaluating floods in basins which lack statistics. Bazoft subbasins have the potential to produce flood, while they face lack of statistics in many cases. With physiographic information and digital maps of the area and also with available statistical data in 30 studied basins (figure 3), the possibility of establishing logical relations between physiographic features and flood discharges with different return periods will be investigated. On the other hand, a GIS data bank seems necessary for easy access in later applications and capability of updating information and relations in any of these subbasins. Information on flood discharge (with different return periods), as the most important distinguishing parameter of floods, is especially important. In floods with shorter statistical period, establishing a regional relation between physiographic characteristics of the basin or subbasin seems logical. After completing and prolonging statistics, different statistical distributions will be fitted using SMADA software. Predicted value of statistical distributions (Log Pearson type3, Pearson type3, Gamble) and observational data were used to find the most appropriate distribution in least squares test and a distribution was selected for each station. With these distributions, flood discharges with different return periods of 2 to 1000 years were estimated. Then, physiographic features of the basin (like area, perimeter, and average slope of the basin, length of the main canal and shape coefficient) were linked with predicted discharges of different return periods using linear regression and multi-variable nonlinear regression in Minitab software. A larger number of parameters are involved in flood predicting models used for estimating discharges with short return periods.

quaternary period have always changed landforms, identifying and detecting traces of these changes is an important topic for geomorphologists. Natural glacier remains from this period are one of the most important evidences of climatic changes and evolutions.
The present article detects and identifies glacial traces in Buanat basin. While identifying and introducing glacial traces of the fourth quaternary period using the usual geomorphic methods, it reconstructs environmental conditions in the coldest glacial phase and investigates the previous water-ice balance in the area. In this regard, annual average temperature in the area under study was 9.6 °C colder and precipitation in lower altitudes was 1.2 to 1.8 more than today which prepared appropriate conditions for glacier activity. Moreover, geomorphic evidences like glacial cirque, glacial valleys, and hanging valleys in the area prove the presence of glacial traces in the basin.
Findings of the present study proves the presence of glacial traces in the basin and provides the basis for future soil and water studies and land use planning.

Determining parameters like precipitation-snow, snow depth-discharge and temperature are especially important in predicting flow in mountainous areas and studying activities of river system. Regarding snow hydrology, determining appropriate snow melting models of the area are important. Therefore, the present article studies effective factors in snow melt, investigates different models of snow melt and introduces the best snow melt model.

North Eastern hillside of Karkas Mountain is located in South Western region of Natanz County with a North West-South East direction. The area is located in 51° 30´ to 52° 4´ Eastern longitude and 33° 26´ to 33°  48 ´ Northern latitude. The lowest altitude is about 970 meter which goes up to 3895 meter in Karkas arête. Study area borders with two basins named Natanz (Ure, Tame) and hanjan (Barzrud, Chime Rud), both of which are located in Ardestan basin.
Two major geomorphologic units of the area includes:-High elevations of Karkas which are mainly more than 3000 meters high.
-A low area with 970 meters in the lowest points which is a part of subsided strip of Qom-Ardakan.
Geological structure, climatic diversity, lithological features, current topography and hydrology of the area and active morphodynamic factors have resulted in significant diversity of geomorphologic phenomena in North Eastern hillside of Karkas Mountain. So that glacial morphogenesis system dominates the higher elevations of Karkas Mountains while arid, erosive systems dominates the desert (Badrud Desert).

The present article investigates the effects of economic situation on food security of different social groups in sample villages of Paeen Velayat in Mashhad (Khorsan Razavi province). Survey Research is used and data are collected using standard questionnaire. Statistical group consists of 404 households or 1804 individuals from which 40 households were selected from the sample villages using cluster sampling. Results indicate that factors like geographic conditions of the village, land ownership, household head type and place of employment, number of children influence economic condition of the households and their ability in achieving sustainable livelihood. Moreover, there is a significant relationship between economic situation of household head and food security of dependent members of the family. In this regard, mothers and young girls experience the lowest and most fragile situation.

Currently, there is an increased global interest in influences and consequences of some agricultural activities performed to improve the production level, like increasing amount of inputs such as chemical fertilizers, herbicides, pesticides, etc. on the environment and society. Furthermore, wastewater produced by washing stockyards and chicken farms create a large and widespread area covered by different kinds of pollutions.
It has been estimated that less than 1 percent of poison used in America is practically used for pests and the other 99 percent are wasted and released in the environment. 20 years ago every extra ton of fertilizer would add 15 to 20 tons to the global crop production, but today the same amount of extra fertilizer increase the production by only 5 to 10 tons (Hosseini, Shariati, Jihad Sh 258). Environmental factor is one of the factors that should be considered in rural development, as preserving the environment and its values in the face of various pollutions and destructions is very important. In performing rural development plan, soil and water degradation must be avoided with all means.
The present article studies and investigates environmental issues like soil erosion, forest degradation, chemical poisons and fertilizers, etc. in rural development. Afterwards, the importance and necessity of biological issues in rural development, case study and finally the consequences are analyzed.

Recently, city services have faced many problems and issues due to rapid increase in urbanism and lack of a codified system of planning and management in different cities. Irregular and hasty population growth results in heterogeneous constructions without correct urban planning and distribution of facilities and services in a way that makes it impossible for everyone to take advantage of economic, environmental facilities. This results in the centralization of specific institutional-political and economic land use in specific urban areas. Residential areas are also an important part of urban land use and the largest area in most cities is allocated to them. They also face problems like shortage and lack of clear standards in buildings, disregard of quantitative and qualitative household indexes, shortage and costliness of urban lands, materials, establishment in inappropriate places and etc. Thus considering issues and problems facing urban household, an analysis and evaluation of the present house hold situation in different neighborhoods of Ilam was necessary for appropriate planning, qualitative and quantitative improvement of households and preventing irreparable damages.
In order to identify different insufficiencies in neighborhoods, it was necessary to collect information using questionnaire and analyze them using SPSS and Excel.
Results indicate that different urban neighborhoods have different qualitative and quantitative indexes, they have different level of access to urban facilities and services and their appearance is completely different. So that among 16 neighborhoods, suburban areas including 3 neighborhoods do not have access to the least household possibilities and standards. It is assumed that other neighborhoods have better situations and there is a significant relation between income level and the household quality.

Heavy rainfalls with thunder is an environmental phenomenon in Western part of the country. Western areas of the country are potentially prone to heavy thunder stones, since they face the direction of Western Winds and Mediterranean humidity and also because of the Zagros Elevations. Upper atmosphere data in the National Center of Environmental Prediction was used for synoptic study of the heavy rainfall on May 2nd, 2010. The condition of atmosphere during the heavy rainfall was analyzed by computational and graphical methods. Results of the synoptic analysis indicates that factors like blocking and twist in 500, 600 and 700 hPa, instability, convection in all atmospheric levels from 500 to 1000 hPa and positive vorticity in 500, 600, 700, 850 hPa were among affective factors in the occurrence of heavy rainfall on May 2nd 2010. According to the humidity-wind maps, the humidity resources of this heavy rainfall were located in 1000 to 850 Persian Gulf alignments and 700, 600, and 500 hPa of the Mediterranean Sea and the Red Sea.

Tourism development in deprived regions with necessary tourism potentials is a strategy which has recently attracted the attention of different countries of the world. In different parts of the world, preserving the environment, ecosystem and the wildlife are considered important. The present article investigates geomorphology of Ilam Province in Western parts of the country emphasizing on geotourism resources. Geomorphologic diversity of the province have created unmatched resources in geotourism which are able to turn the Province into a tourist attraction. The present study identifies geologic and geomorphologic characteristics of straits in this Province and provides necessary solutions for using this valuable resource. Moreover, it identifies unique features of this landforms emphasizing on their attraction.

According to the Greek scholar, Eratosthenes (194 BC), geography is the study of Earth as the place for human beings. In studying the Earth, geography faces different physical and human factors.
Human-environment relation is the underlying concept of geography. Environment consists of natural, human and social environments in which human beings have multiple actions and roles to play. Understanding the environment and using geographic capacities and capabilities like seas, lakes, ponds, waterfalls, forests, plantations, mountains, and sacred, ancient and cultural centers, it is possible to attract tourists and endeavor for development and income increase. As the main element of tourism in spatial crystallization, environment plays an important role in attracting tourists and provide diverse tools. Generally, the focus of geographic environment is on society and it is not possible to separate physical and spatial conditions. Every geographic perspective reveals human consistency and alignment with spatial conditions. Since every geographic area has its specific features, natural and cultural attractions are formed in accordance with them and thus there are different areas of tourism