Iran Ghazi; Reza Mokhtari Malek Abadi
Volume 14, Issue 54 , August 2005, , Pages 20-25
Abstract
Today quality of human life is unstable, therefore it is necessary to assess the quality of human environment and identify the causes of instability. This requires identifying the variables affecting the environment, achieving a method for having and assessing criteria for supervision and control of ...
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Today quality of human life is unstable, therefore it is necessary to assess the quality of human environment and identify the causes of instability. This requires identifying the variables affecting the environment, achieving a method for having and assessing criteria for supervision and control of the responses that society takes to repair instabilities. Environmental, economic, social and cultural indicators have emerged as a key tool for definition and follow-up of operations and strategies that lead to a sustainable development and analysis of the benefits and costs of development. According to these indicators such as literacy, income, poverty eradication, health, enjoyment of healthy water and air, leisure, women's participation in social, economic, cultural and environmental activities, etc., it is possible to assess the stability and instability of society, and in order to achieve sustainability, all indicators of sustainability should be considered simultaneously. In the course of development, it is undesirable that some people grow economically and the rest remain in poverty. In addition, it is necessary that the development be in a manner that it realize social and political solidarity, coordination in practice, participation of all sectors and individuals (including women) and increase of technological productivity while avoiding ecosystem degradation.
Mohammad Mosayyebi
Volume 6, Issue 24 , February 1997, , Pages 20-23
Abstract
Based on the reports published in global health magazines, about one-fourth of people of the world are deprived of suitable shelter, and a hundred million people have no house and lie in streets, under bridges and in other improper places. Therefore, housing is a global problem, and it is certain that ...
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Based on the reports published in global health magazines, about one-fourth of people of the world are deprived of suitable shelter, and a hundred million people have no house and lie in streets, under bridges and in other improper places. Therefore, housing is a global problem, and it is certain that traditional patterns and methods can by no means respond acceptably to these increasing need. Furthermore, other factors such as environmental considerations, lack of enough investment and skilled force and natural problems are among the limitations of housing plans and management.
It is obvious that creation and establishment of efficient and modern architecture and urban texture in agreement with the culture of time and place must be based on leaving classic characteristics and removing the single-story attitude. Moreover, for achieving agreement between housing and urban texture from artistic and social order point of view, we must consider environmental, artistic and social order balance together when analyzing the relationship between human and housing.
Attention to historical characteristics of each nation is a necessity in housing plans that is very effective in the success and comprehensiveness of these plans.
Considering that in large cities the problems of transportation, air pollution, shortage of space, excessive occupation of urban lands by highways, inefficiency in movements within the city and countless environmental problems are due to lack of a comprehensive plan in design of residential spaces, so due care in management and housing plans is the first step for avoiding such problems.
In this paper, while considering the environmental problems of cities, the main sources of environment, namely matter, energy, space, time and variety have been taken into account, and it has been emphasized that it is necessary to define quantitatively a comprehensive plan containing all factors that affect housing plans, and to implement it into geographic information systems. Then, using GIS software and computer modeling, the layers or combinations of such plans should be assessed and, considering their advantages and disadvantages, the best approach for housing plans shall be proposed according to national culture and environmental conditions.
Ahmad Sarkhosh (Translator)
Volume 10, Issue 37 , May 2001, , Pages 21-23
Abstract
Today, there are probably few people not familiar with the technology of Geographic Information System or GIS. This technique has existed since the 1970s and following the introduction of hardware facilities into the world of science and technology, and was then used in the Canadian Department of Natural ...
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Today, there are probably few people not familiar with the technology of Geographic Information System or GIS. This technique has existed since the 1970s and following the introduction of hardware facilities into the world of science and technology, and was then used in the Canadian Department of Natural Resources Management and Planning. With the arrival of new facilities, which gave computers a legendary speed and capacity compared to their ancestors, a huge progress has occurred in this area so that utilization of GIS, or spatial information management, has entered different fields: vast arenas of natural resources including forests, pastures and water resources (such as the oceans, seas and lakes), and even the smallest parts of human life such as homes and cars.Considering the widespread application of this technique, whose scientific and theoretical aspects have overtaken its technical dimension, and the need of the enthusiasts to be aware of the advancements in this field, this paper, under the title “The Consortium of GIS Application for Water Resources with the Aim of Designing Object-Oriented Models” is translated from the source ARC News Vol.21 No.4-Winter: 199/2000; hopefully it will be useful for interested people.
Ahmad Javaheri; Ebrahim Gholipour
Volume 16, Issue 63 , November 2007, , Pages 22-25
Abstract
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 ...
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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.
Ali Hanafi; Iraj Hatami
Volume 22, Issue 87 , November 2013, , Pages 24-28
Abstract
Climatic zoning and identifying influential factors and elements in each zone are considered to be the most important factor in environmental planning. Climatic research and climate map can be used in large, medium, small and local scales. Related researches in Kurdistan have been very limited. The present ...
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Climatic zoning and identifying influential factors and elements in each zone are considered to be the most important factor in environmental planning. Climatic research and climate map can be used in large, medium, small and local scales. Related researches in Kurdistan have been very limited. The present article investigates climatic features of Kurdistan province in a 30 year statistical period using weather stations and Information Technology System software. After qualitative and quantitate control of meteorological data and elimination of statistical deficiencies, two important climatic elements (temperature and precipitation) were investigated across the province. Afterwards, isothermal and isohyetal maps and the correlation between temperature and rainfall with altitude were produced using inverse distance weighting method. Conformity of temperature and rainfall with digital elevation model shows a significant inverse correlation between temperature, rainfall and altitude. So that with an increase in altitude, temperature and rainfall decreases. De Martonne and Embergent methods were used for climatic classification of the province. In De Martonne classification, Kurdistan province was divided into four climates, i.e. arid, Mediterranean, humid and very humid. Embergent method classified the area into four climates, i.e. cold semi-arid, highland climate, cold semi-humid and cold humid. Finally, zoning process was performed in GIS environment and inverse distance weighting method was used for spatial interpolation and spatial data analysis to produce Kurdistan climate map. Resulting zoning maps indicates that semi-arid and Mediterranean climate are dominant and only a small zone in the western parts has humid and semi-humid climate.
Ghasem Keykhosravi; Zahra Yarmoradi
Volume 23, SEPEHR , July 2014, , Pages 25-31
Abstract
Supplying crops’ water needs in arid areas is only possible through irrigation, since low precipitation, high evaporation and inappropriate distribution of rainfall makes dry farming economically unjustifiable. Yet, perennial rivers cannot supply water needs of different sectors, and the shortcomings ...
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Supplying crops’ water needs in arid areas is only possible through irrigation, since low precipitation, high evaporation and inappropriate distribution of rainfall makes dry farming economically unjustifiable. Yet, perennial rivers cannot supply water needs of different sectors, and the shortcomings must be compensated from other areas like underground resources. In arid and semi-arid areas, inconstant distribution of precipitation across time and space and lack of appropriate vegetation have changed the life-giving precipitation into a natural disaster which becomes useless in the form of devastating flood. In such areas, artificial feeding of groundwater resources by floodwater is a way of preventing land degradation.
In the present article, we first produced different maps (slope, soil, land usage, Isohyetal) of Sabzevar city. Then adapting information layers using GIS, appropriate places for artificial feeding of groundwater were exploited. Afterwards, distribution map of Quaternary alluviums across the city was exploited in GIS environment to determine appropriate places for distributing floodwater.
Results indicate that 3279.96 km2 (out of 20502 km2, 16%) are appropriate for artificial feeding plans, and around 6017.76 km2, i.e. around 29.4 percent of the city area are appropriate for floodwater distribution plans. Finally integrating these two maps, an area of around 1591.56 km2 (7.76%) is estimated to be appropriate for artificial feeding and distributing floodwater in this city.
Kamal Omidvar
Abstract
Abstract
In most parts of the country, especially at high altitudes, the predominant form of precipitation is snow, which can be considered as the main source of water for rivers, springs, underground watersheds and Qanats. The heights of Yazd province are also one of the snowy areas of the country ...
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Abstract
In most parts of the country, especially at high altitudes, the predominant form of precipitation is snow, which can be considered as the main source of water for rivers, springs, underground watersheds and Qanats. The heights of Yazd province are also one of the snowy areas of the country because of geographical location and topographic conditions. The purpose of this research is to synoptically-dynamically identify, study and analyze the snowfall in Yazd Province. For this purpose, 12 snowfall periods were identified during the statistical period of 1999 to 2011 after identifying the geographical location of the area and with regard to the required data. To identify the motion of the air mass and to study the synoptic systems of the province, daily snow and rainfall data and synoptic maps of the land surface and upper levels of the atmosphere, jet stream, omega, circulation and humidity advection were extracted from the NCEP/NCA base and the related maps were plotted in the GrADS environment. Three synoptic and pressure patterns were extracted after conducting climatic thermodynamic researches affecting Yazd province and studying dynamic properties in terms of strengthening and weakening of pressure systems and their synoptic analysis. In the first pattern, the low-pressure combinative systems of the Eastern Mediterranean and Sudan along with the deepening of the Eastern Mediterranean troughs and the penetration of cold weather cause snowfall, especially on the highlands of Yazd province. In the second pattern, the emergence of the blocking phenomenon causes snowfall and severe cold in Yazd province. This phenomenon occurs along with deep troughs of the Eastern Mediterranean and the Red sea leading to cold weather and snowfall for several days. In the third and final pattern, with the establishment and high pressure penetration of the Caspian Sea and the Siberia and the creation of a cut-off low-pressure phenomenon in the central and northern parts of Iran, a snowfall occurs in the central regions of Yazd province.
Mohsen Abbasnia; Taqi Tavousi; Mahmood Khosravi; Toros Hossein
Abstract
Recognizing and evaluating the climate changes in the coming decades is absolutely necessary for the purpose of appropriate environmental planning in order to adapt and mitigate its effects. In this research, the SDSM model was successfully calibrated and validated (1981-2010) tocomparatively analyze ...
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Recognizing and evaluating the climate changes in the coming decades is absolutely necessary for the purpose of appropriate environmental planning in order to adapt and mitigate its effects. In this research, the SDSM model was successfully calibrated and validated (1981-2010) tocomparatively analyze and explore the future maximum daily temperature variations over Iran forthe two future periods of (2041-70 and 2071-99) and based on the output of two general circulation models of atmosphere, namely, Hadcm3 and CGCM3 under the existing emission scenarios (A1B, A2, B1, B2), relative to the baseline period of 1981-2010. In other words, with regard to the uncertainty for the maximum daily temperature of the future data, downscaling was performed in 7 synoptic stations as the climatic representatives of Iran. Analysis of the output uncertainty showed that CGCM3 model under the B1 scenario among all different models-scenarios has had the best performance in simulating the future temperature. Also, the findings of the research on the studied stations indicate that the temperature in Iran in the middle and final decades of the 21st century increases in averagebetween 1 to 2 degrees Celsius, which based on different scenarios of the Hadcm3 model, this temperature increase has been higher compared to the CGCM3 model. In terms of spatial dispersion of the changes in the GIS environment based on the output of all scenario-models, the lowest temperature increase was observed at Bandar Abbas station located on the south lowland coast of Iran, and on the contrary, the temperature rise reaches the maximumat the Tabriz station located onthe northern latitudes and highland and mountainous regions of Iran. In total, the important and effective factors in the future changes of Iran's temperature can be classified into three groups: factors of altitude, latitude and atmospheric humidity, because, based on all the outputs of model-scenarios, the stations located on the northern latitude elevations of Iran will experience the highest temperature rise compared to the stations located on low-altitude and adjacent to the southern coast of Iran.
Mohammadzaman Ahmadi; Saeed Behzadi
Abstract
Abstract
Wells are one of the main sources of drinking water, agriculture and industry. Water quality in terms of drinking is the most important parameter among qualitative parameters. Therefore, the investigation and anticipation of pollution are the goals of managers and planners. In this research, ...
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Abstract
Wells are one of the main sources of drinking water, agriculture and industry. Water quality in terms of drinking is the most important parameter among qualitative parameters. Therefore, the investigation and anticipation of pollution are the goals of managers and planners. In this research, artificial neural network and geospatial information system have been used to determine the contamination of magnesium parameter in the water of Gonbad villages in Golestan province during the 4 consecutive of 2008, 2009, 2010 and 2011. In this model, the artificial neural network has been evaluated in Perceptron structure with a number of hidden layers and various neurons. At present, pollution of underground is increasing due to the chemical and industrial activities. Therefore, it is necessary to identify vulnerable areas to prevent the pollution of groundwater. Also, in this research, to determine the groundwater contamination, maps such as topography, geology, location of wells, slopes and …, were used in spatial environment. After determining the amount of contamination using the neural network models and the output of the model in spatial environment, the pollution maps were obtained. Also, by observing contamination maps and data available in the aforementioned years, it can be concluded that the level of pollution was low and this pollution cannot be dangerous.
Ezzatollah Ghanavati; Reza Mansouri; Seyyed Abdolsalam Heydari
Volume 22, Issue 86 , June 2013, , Pages 29-41
Abstract
Coastal Zones have been one of the most populated areas on the Earth.Nowadays, abut 60 percent of the Population lives in costal zones. In most coastal countries, cities in the coasts have high population density. In respect to the highly populated costal areas and human’s exploitation of their ...
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Coastal Zones have been one of the most populated areas on the Earth.Nowadays, abut 60 percent of the Population lives in costal zones. In most coastal countries, cities in the coasts have high population density. In respect to the highly populated costal areas and human’s exploitation of their gifts on the one hand, and the fact that 1/3 of world population reside on these areas on the other, the significance of further exploration and examination of these areas comes into figure. It is true abut Iran which has a long coastal line including the Caspian Sea, Sea of Oman and the Persian Gulf. Thus the importance of the various problems caused by different factors, natural and human-created on the coasts, requires the use of new technologies to the integrated management and sustainable develop ment of these areas in line with the system perspective to action. Based on different scopes, different method of are available for the classifications of beaches. Smartline format has been used and refined during 2007-2009 to create a detailed nationally consistent coastal geomorphic )landform( map of Australia, by combining data from over 200 prior map ped data sources. The Coastal Smartline Geomorhic and Stability Map of Australia was compiled in the first instance for use in assessment of Australia’s coastal vulnerability to sea-level rise and climate change by the Commonwealth Department of Climate Change and Geosience Australia. Accordingly, this paper exploits this method for mapping the coastal zones of Iran.
Bakhtiar Feizizadeh; Salimeh Abdolah Abadei; Khalil Valizadeh Kamran
Abstract
Extended Abstract DigitalElevation Model (DEM) is one of the main geographical datamodels which forms the basis of the different spatial analysis. DEM is known as fundamental data for many modelingtasks. Nowadays, the result validation of GIS spatial analysis, hasbecome a major challenge in the ...
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Extended Abstract DigitalElevation Model (DEM) is one of the main geographical datamodels which forms the basis of the different spatial analysis. DEM is known as fundamental data for many modelingtasks. Nowadays, the result validation of GIS spatial analysis, hasbecome a major challenge in the world of GIS.Thequality of a DEM is dependent upon a number of interrelatedfactors, including the methods of data acquisition, the nature ofthe input data, and the methods employed in generating the DEMs.Analysis of uncertainty in different fields, due to data qualityand related issues such as error, uncertainty models, error propagation, error elimination and uncertainties in the data, are felt morethan any other times. Of all these factors, data acquisitionis the most critical one. Previous studies on DEM dataacquisition have focused either on examination of generation method(s), oron case studies of accuracy testing. These studies are not adequate,however, for the purpose of understanding uncertainty (an indicator used toapproximate the discrepancy between geographic data and the geographic reality thatthese data intend to represent) associated with DEM data and thepropagation of this uncertainty through GIS based analyses. The developmentof strategies for identifying, quantifying, tracking, reducing, visualizing, and reportinguncertainty in DEM data are called for by the GIS community. In order to apply uncertainty analysis on DEMs, this studyaimed to evaluate the error rate and uncertainty of elevationdata obtained from SRTM and ASTER satellites. The objectives ofthis study are: (1) to understand the sources and reasonsfor uncertainty in DEMs produced by cartographic digitizing; (2) to develop methodsfor quantifying the uncertainty of DEMs using distributional measures and (3) to measure the uncertainty associated with DEMs and minimizethe chances of error by means of optimizing models. Quantifying uncertaintyin DEMs requires comparison of the original elevations (e.g. elevations read from topographic maps) with the elevations in aDEM surface. Such a comparison results in height differences (orresiduals) at the tested points. To analyze the pattern ofdeviation between two sets of elevation data, conventional ways areto yield statistical expressions of the accuracy, such as the rootmean square error, standard deviation, and mean. In fact, allstatistical measures that are effective for describing a frequency distribution, including centraltendency and dispersion measures, may be used, as long asvarious assumptions for specific methods are satisfied. Our research methodology includesseveral steps. The first step was, using the statistical indices ME, STD and RMSE, the error rate of DTMsforobtaining the chances of error in ach model. It hasto be mentioned that the main attraction of the RMSElies in its easy computation and straightforward concept. However, this indexis essentially a single global measure of deviations, thus incapable ofaccounting for spatial variation of errors over the interpolated surface. Inorder to obtain more accurate results, then uncertainty of dataerrors was also simulated by Monte Carlo method and errorpropagation pattern was extracted by interpolation of results. The resultsof this step show that, the DEM derived from pairstereo ASTER despite having better spatial resolution, included more errorsand practically lacking the details of DTM 30 meters. Finally,removing the error propagation pattern from DEMs, the secondary DEMwas produced. By recalculating indicators describing the error and comparingthese values with the initial values, the results indicate that,both DEMs show more accuracy after eliminating the error propagationpattern. TPI Index was used to determine the location ofbasin topography and the basin is divided into 6 classesand error rate in each class was calculated before andafter the simulation. The results showed that, the error ratesin all classes before and after the simulation in bothDEMs were reduced. In terms of uncertainty analysis methods forDEMs, results of our research indicated that the RMSE methodsalone is not sufficient for quantifying DEM uncertainty, because this measurerarely addresses the issue of distributional accuracy. To fully understand andquantify the DEM uncertainty, spatial accuracy measures, such as accuracy surfaces, indices for spatial autocorrelation, and variograms, should be used. Results alsoindicated that Monet Carlo simulation is indeed sufficient methods forsimulation error in DEMs. Results of this research are of great importance for uncertainty analysis in domain of Geosciences andcan be used for improving the accuracy of modeling in avariety of applications.
Abdolazim Ghangormeh; Javad Malek
Abstract
The Caspian Sea like all other seas andgreat lakes is constantly turbulent under the influence of various hydrodynamic phenomena such as storm tide, storm surges caused bythe wave and wind, rise of wave in the coastal zone, and the phenomenon of resonance.But the reason for all of these phenomena is ...
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The Caspian Sea like all other seas andgreat lakes is constantly turbulent under the influence of various hydrodynamic phenomena such as storm tide, storm surges caused bythe wave and wind, rise of wave in the coastal zone, and the phenomenon of resonance.But the reason for all of these phenomena is the forces caused by the air pressure and wind fields on the sea.In this research, the effects of air and wind pressure data (components) on observational levels in the level measuring stations of Bandar Anzali, Noshahr, Bandar Sadra (Neka) and Ashuradeh were investigated.For this purpose, the hourly data of the water level of the aforementioned stations during a four-year period (2000-2003) and also the data of air and wind pressure on the Caspian Sea were used with temporal-spatial resolutions of 6 hours and 0.25 degrees (25 km) during a 4 year period onwards.To study the range of the effects of these factors (air andwind pressure) on the data of the level measuring stations, the 50x50 to 250x250 km networks (with 50km sequence) were extended towards the main body of the sea. A linear multivariate regression model was used to determine the coefficients and the amount of the effect of wind and air pressure components, and the results were obtained monthly for each station. The results show that, by modeling a wider field of air and wind pressure effectiveness on the water zone overlooking each station, the calculated and observed results of the water level data are more correlated, so that the maximum correlation coefficient for the 250x250 km field for the Anzali stationsis 0.864 in November, for Noshahris 0.909 in November, for Sadra (Neka) is 0.893 in March and for Ashoradeis 0.873in April.
Hassan Beik Mohammadi
Volume 15, Issue 60 , February 2006, , Pages 32-35
Abstract
The Orient is the birthplace of civilization, and Sistan is one of the centers of culture and civilization in Southwest Asia. Sistan is also the birthplace of the national, cultural and social epics of ancient Iranian history. Sistan Plain, located in the eastern part of Iran, is the center of one of ...
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The Orient is the birthplace of civilization, and Sistan is one of the centers of culture and civilization in Southwest Asia. Sistan is also the birthplace of the national, cultural and social epics of ancient Iranian history. Sistan Plain, located in the eastern part of Iran, is the center of one of the ancient civilizations due to its special geographical position in the mouth of the Hirmand River and its branches, and the exploitation of its water resources and fertile alluvium in the light of agricultural activities and cultural functions. According to archaeologists' findings, in a few millennia B.C., one of the oldest urbanization and civilization models was formed in the burnt city of Sistan, more ancient than the Sumerian civilization. The Sistan province, thanks to its geographic location, has since the dawn of history enjoyed such an economic enrichment that has won for it the title of "Asia's Granary." In this paper, which is prepared by methods of secondary and analytical research, the researcher has tried to determine the antiquity, status, the real face of historical geography, economic, cultural and social role of Sistan among the civilizations of Southeast Asia through collecting and analyzing historical and geographical documents.
Samira Hosseini; Hamid Ebadi; Yasser Maghsoudi
Abstract
Extended Abstract
Introduction
Estimation of forest biomass has received much attention in recent decades including assessing the capability of different sensor data (e.g., optical, radar, and LiDAR)and the development of advanced techniques such as synthetic aperture radar (SAR),polarimetry and polarimetric ...
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Extended Abstract
Introduction
Estimation of forest biomass has received much attention in recent decades including assessing the capability of different sensor data (e.g., optical, radar, and LiDAR)and the development of advanced techniques such as synthetic aperture radar (SAR),polarimetry and polarimetric SAR interferometry for forest biomass estimation. Accurate estimation of forest biomass is of vital importance to model global carbon cycle. Deforestation and forest degradation will result in the loss of forest biomass and consequently increases the greenhouse gases. Radar systems including SAR have a great potential to quantify biomass and structural diversity because of its penetration capability. These systemsare also independent of weather and external illumination condition and can be designed for different frequencies and resolutions.Moreover, SAR systems operating at lower frequencies such as L- and P-band have shown relatively good sensitivity to forest biomass. Regression analysis is among thecommon methods for evaluation forest biomass which have been investigated for many years on different areas. This analysis is based on the correlation between backscattering coefficient values and the forest biomass. However, previous studies demonstratedthat such approaches are very simple and they do not consider structural effects of different species. One of the restrictions and limitations of these methods is the low saturation level. The level of saturation is lower in higher frequencies and vice versa. Considering the structural parameters, researchers have tried to use the interferometry techniques.Forest canopy height is one of the important parameters that can be used to estimate Above Ground Biomass (AGB) using allometric equations.
Materials &Methods
Recentforest height retrieval methods rely on model based interferometric SAR analysis. The random volume over ground (RVOG) model is one of the most common algorithms. This method considers two layers, one for the ground under the vegetation and one for the volumetric canopy. This model has been investigated in different forest environments (e.g. tropical, temperate and boreal forests). Estimation of forest biomass based on forest height using allometric equations can overcome radar signal saturation to some extent.Improvement of Forest height estimation can play an important role to retrieve accurate forest biomass estimation. In this paper, a new method using scattering matrix optimization is introduced to extract forest height by changing polarization bases. Scattering matrices for slave and master images have been extracted by changing polarization bases. Then polarimetric interferometry coherences have been calculated and forest height was estimated by various forest height methods including DEM Difference, coherence amplitude inversion, RVOG Phase, Combined and RVOG.
Results& Discussion
P-band full Polarimetric synthetic aperture radar (SAR) images acquired by SETHI sensor over Remningstorp (a boreal forest in south of Sweden) were investigated for forest biomass estimation.Mean of Lidar height values which fall in each shapefile was used to check corresponding results with the heights of retrieval methods.
The results of tree height retrieval methods without changing polarization bases between PolInSAR tree height and LIDAR height show that three methods including coherence amplitude inversion, RVOG Phase and RVOG have low R2 value. DEM Difference and combined methods yielded better results in comparison with the other three aforementioned methods; however the results are not satisfactory.DEM Difference method underestimated the tree height compared to that of LIDAR. This is perhaps due to the fact that volume phase center does not lie at the top of the tree.Temporal decorrelation decreases volume correlation, consequently small values in the SINC function lead to generate large values in results; therefore RMSE of coherence amplitude method is relatively high.New master and slave scattering matrices in arbitrary polarization basis were extracted by alteringandin transformation matrix.Results show that RVOG phase has the best result with R2=0.76 and RMSE=3.76. Following this method, DEM difference method shows R2=-0.69.It is likely that methods which include phase information by changing geometricalparameters, in transformation matrix (e.g. RVOG phase and DEM difference) significantly increase the tree height accuracy.sOn the other hand, methods that only apply magnitude of coherence such as coherence amplitude method do not show notable improvementfor retrieving tree height.
Conclusion
Robustness of forest height estimation using Scattering Matrix Optimization by changing Polarization Bases was studied in this paper.PolInSAR data was acquired by SETHI on Remningstorp, a boreal forest in south of Sweden. Results indicated that forest height retrieval methods which included phase parameter shows remarkable improvement by changing the geometrical parameters for height estimation.Therefore RVOG phase method with R2=0.76, RMSE=3.76m and DEM Difference method with R2=-0.69 gave the best results, whereas coherence amplitude method which only included magnitude of coherence with R2=0.17 showed the lowest correlation.
Samad Shadfar
Abstract
One of the types of environmental hazards that causes the destruction of agricultural lands, rangelands and Infrastructure in many parts of the country is gully erosion. In this research, fuzzy logic operators were used with the aim of determining the different hazard zones,obtaining the area of each ...
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One of the types of environmental hazards that causes the destruction of agricultural lands, rangelands and Infrastructure in many parts of the country is gully erosion. In this research, fuzzy logic operators were used with the aim of determining the different hazard zones,obtaining the area of each one of them, and presenting the map of the gully erosion hazard in Troud watershed. In order to achieve this goal, satellite imagery, interpretation of 1:20000 scale aerial photos, 1:50000 scale topographic maps, 1:100000 scale geological maps, field studies and ArcGIS software have been used as the main research tools. To do this, at first, some of the effective variables which had more important roles in the formation and development of gully erosion, as well as the areas with gully erosion, were identified. In the next stage, the effective factor classes were weighted and the gully erosion map was prepared using fuzzy operators including fuzzy algebraic sum, fuzzy multiplication, fuzzy gamma 0.5 and fuzzy gamma 0.8 in the GIS environment.The results indicate that in the fuzzy algebraic summation method, 100% of the gully areas are located in very highclass, in the fuzzy algebraic multiplication, 83.29% of the gully areas are located in low class, in 0.8 fuzzy gamma method,60.93% of the gullies are located in low class and about 17 %are located in high and very high classesbut, in 0.5 fuzzy gamma method, around 1.5% of the gully areas are located in low class and about 62% are located in high and very high classes.
Mahtab Safari Shad; Mahmoud Habibnejad Roshan; Alireza Ildoromi
Abstract
Abstract The issue of drought is very important in water resources studies. Meteorological drought indices are calculated directly from meteorological data such as rainfall, and in the absence of such data, they will not be useful in monitoring drought. Therefore, remote sensing techniques can be considered ...
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Abstract The issue of drought is very important in water resources studies. Meteorological drought indices are calculated directly from meteorological data such as rainfall, and in the absence of such data, they will not be useful in monitoring drought. Therefore, remote sensing techniques can be considered as a useful tool in monitoring drought. In this research, using MODIS remote sensing satellite images, the trend of vegetation normalized index changes in Isfahan province for the years 2000-2008 was investigated. In addition to vegetation, NDVI index can be effective in addition to natural vegetation for drought monitoring, especially for drought monitoring of dry farming type.Considering this index, the vegetation cover was classified into 4 groups and the area of each of the classes was calculated. Finally, two SPI and NDVI indices were compared. The result of calculating the SPI index show that the occurrence of severe drought is in 2008 and moderate droughts are in 2000 and 2001 in Isfahan province respectively. The calculation of the NDVI index in these three years also indicated that the poor vegetation cover has been significantly increased. High level Pearson correlation (+0.704) was observed between SPI and NDVI in significant level of 0.01. However, the results of the effect of rainfall on the NDVI index showed that there is no coincidence of the occurrence of meteorological drought and agriculture droughts in all years. For the year 2006, despite the fact that precipitation was higher than the years before and the years after and more than the average rainfall of the province, but based on the results of the NDVI index, agricultural drought has occurred this year (Devaluation of the NDVI index). On the contrary, in 2002 and 2004 that precipitation was lower than 2006, but dry farming and pasture conditions were better than 2006. And also, in 2003 with a difference of 2 mm in precipitation compared to 2002, the NDVI index value dropped significantly. The results of this research double the necessity of defining a profile that expresses all of these issues.
Mohammad Eskandari nodeh; Leila Sayyad Bidhendi
Volume 21, Issue 84 , February 2013, , Pages 35-54
Abstract
Informal Settlement is one of the urban problems whose most important trait is insecurity of possession, abnormal house structure structure condition, less access to urban services and safe nutrition, and extra density. These conditions are especially more apparent in undeveloped countries. In ...
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Informal Settlement is one of the urban problems whose most important trait is insecurity of possession, abnormal house structure structure condition, less access to urban services and safe nutrition, and extra density. These conditions are especially more apparent in undeveloped countries. In these countries, more than 50 or 75 percent of the population live in informal settlements. In Iran also, the problem of informal settlement appears clearly from decade 1340 afferwards, when the rate of urbanization was on its apex, by which cities confronted serious problem which has been always increasing.
In Iran, the state has endeavored to organize informal settlement. These efforts are necessary due to what constitution emphasizes in clauses 3 and 31 about the right of Iranian citizens to have suitable shelter and appropriate house. This research tries to evaluate state policies in organizing informal settlement in Bandar-e-Abbas by applying Factor Analysis and Likert methods. This research uses quantitative and then qualitative analysis methods. Results indicate that the state was not much successful in organizing and empowering informal settlement indexes in Bandar-e-Abbas. Finally some conclusions and suggestions are presented.
Ahmad Pourahmad; Hossein Hataminejad; Mahdi Modiri; Ashraf Azimzadeh Irani
Abstract
Introduction
Preservation and maintenance of historical urban fabrics or fabrics containing cultural heritage of cities is of special importance, because these fabrics, in addition to creating a sense of identity and stimulating national pride, improve the citizens' quality of life. "Improvement"is ...
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Introduction
Preservation and maintenance of historical urban fabrics or fabrics containing cultural heritage of cities is of special importance, because these fabrics, in addition to creating a sense of identity and stimulating national pride, improve the citizens' quality of life. "Improvement"is one of the methods and, of course, the most appropriate one, of intervention in the historical fabrics of cities, because in this type of intervention, the principle is based on "loyalty to the past and the preservation of identity-stimulating effects".
Improvement activities are aimed at using available potential and actual facilities, strengthening positive aspects and weakening negative ones. In each of the improvement measures, no significant intervention is performedin the physical aspect, and only by replacing the proper functioning of activity, the erosion of this type of urban space is prevented, and by making changes in urban activities, favorable urban spaces are created. Since the observance of the "passive defense requirements" as well as the "sustainable urban development principles" is an essential requirement in selecting the appropriate pattern for the improvement of the old urban fabric, the study of the principles governing these two concepts indicates thatcontradictions exist between these principles. In the present study, we have mainly studied and examined these two important and influential concepts on the improvement patterns of historical urban fabric, and carried out a comparative study of the principles governing them. The purpose of this research is to outline the contradictions between the requirements of passive defense and the principles of sustainable urban development in the improvement pattern of urban historical fabric and to find a suitable solution in this regard.
Materials & Methods
The research method was applied in terms of the aim, and descriptive-exploratory in terms of conduct. The data gathering method was both documentary (secondary) and field surveys, and analyses were performed using the ArcGIS software and also by the Paired Comparison Analysis method. The historical fabric of the 12th district of Tehran, with an emphasis on the historical element of the museums, was the case study of this paper, which made it possible to achieve the results of the research. In order to prioritize some uses in positions where the studied historical element (museum) are located, from the point of view of passive defense as well as from sustainable urban development perspective, we can use the Paired Comparison Analysis method to achieve the most balanced result, so that the conflict between the two approaches is not significant. First of all, the importance of each single studied use is examined from either of the two perspectives through the spatial analysis ofthe position of that particular use relative to the location of the museums. Then, the view of passive defense concerning each use has been compared with that of sustainable urban development according to the relevant criteria, and scored on the basis of importance.
Results & Discussion
The results of the research show that, in order to find the most suitable pattern of intervention - of improvement type - in the historical fabric, it is necessary that along with emphasis on the requirements of passive defense and principles of sustainable urban development, we must, in addition to prioritizing changes in uses, reduce the grounds for the creation of any kind of contradiction in approaches. Therefore, in the present paper, the uses and elements affecting theregion have been analyzed in relation to the studied fabric (museums). In the investigated pattern, actions and predictions to improve the physical and spatialquality of environment through the replacement of proper operation of activity will prevent the erosion of the historical urban fabric, and by creating changes in urban activities, favorable spaces for the protection of historical fabric will be created.
Conclusion
In spite of the proof of the conflict between "passive defense requirements" and "principles of sustainable urban development", the emphasis on both concepts in the improvement pattern of city’s historical fabric isinevitable.
Therefore, by adopting an appropriate model for improvement and appropriate methods of intervention, it is possible to perform the important task of preserving the historical fabric by optimally changing some of the uses.
Hassan Khosravi; Esmail Haydari Alamdarloo; sahar nasabpour
Abstract
Extended Abstract
Introduction
Water is the principal source of economic development, social security and poverty reduction. The value of water source leads to enhancement of management measures to maintain its quality and quantity by communities. Environmental changes and human activities effect on ...
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Extended Abstract
Introduction
Water is the principal source of economic development, social security and poverty reduction. The value of water source leads to enhancement of management measures to maintain its quality and quantity by communities. Environmental changes and human activities effect on the quality and quantity of water. Urban growth, increasing industrial activities and overuse of chemical fertilizers in agriculture result in pollution of groundwater and surface water which have adverse effect on the health of human beings, animal and plants. Groundwater is the primary source to supply agriculture and drinking water hence recognition and awareness of groundwater quality and the water classification based on the number of various elements of them will assist us in making management decisions and decline groundwater pollution. Groundwater is particularly important in arid and semi-arid areas. On the other hand groundwater deterioration, both in quantitative and qualitative terms is important in water resources management of these areas.
The concentration of common ions in water is one index for assessing water quality. Groundwater quality index (GQI), a combination of parameters for water quality, that constitute a reliable tool in defining aquifer vulnerability is used to investigate the spatial variability. GQI shows the data related to the water quality in an explicit manner. This index presents a way of summarizing the overall qualitative condition of water which is understandable for the audience.
Materials&Methods
Yazd-Ardakan plain has been faced with significant reduction of groundwater level in recent years. So, it is expected that the studying groundwater quality index can be effective for aquifer management in this plain. In this research GQI was used in order to study the distribution of major water ions including Calcium, Magnesium, Sodium, Chloride, Sulfate and Total Dissolved Solids (TDS); and zoning groundwater quality using ArcGIS10.1. The data of 53 piezometric wells provided by Iran Water Resources Management Company were used to study the status of temporal and spatial changes of GQI in Yazd-Ardakan plain. Water quality sampling campaigns were conducted during most vulnerable periods of early and late summer to ensure the representativeness of the targeted GQI under worst case conditions. Quality zoning maps were provided for 2003, 2006 and 2011. For this purpose, data were evaluated in GS+ 5.1 software, after calculation, the best model with the lowest estimated error was selected for zoning water quality parameters. Because of the lowest estimation error, Kriging, Gaussian and Spherical variogram models were selected as appropriate interpolation method for zoning the quality parameters. WHO standards were used to compare and investigate the quality status of the water. The water qualitative groups in the GQI map were divided into 5 classes of good, acceptable, medium, inappropriate, and poor, scoring from 0 to 100. The class which is close to 100 shows better quality and the class which is close to 0 shows lower quality.
Results & Discussion
The results showed that Yazd-Ardakan plain is located in average and acceptable classes according to GQI index. The highest and lowest amount of Groundwater Quality Index (GQI) were in the west and north of the study area, respectively. Moran's I spatial autocorrelation index, GQI and all chemical studied variables except for magnesium have cluster spatial distribution pattern, but Magnesium have random spatial distribution pattern. Three parameters of Total Dissolved Solids (TDS), Sodium and Chloride having the highest coefficient ranking have a highest impact on GQI, respectively. On the other hand, these parameters have a high weight and GQI is more sensitive to them. In fact, these components in Yazd-Ardakan plain groundwater have more impacts on GQI model and their removal will cause greater changes in GQI. Therefore, they should be carefully evaluated and monitored. Generally, it can be concluded that GQI has the descending trend in the study area and land use has the important role in reducing GQI index and water quality. It can also explain the overall quality of groundwater and its threats in various uses of water. Finally, the regions with poor groundwater quality can be targeted for detailed studies and monitoring programs.
Conclusion
According to the results, due to the nature of natural phenomena such as drought, their complete removal is not possible. The only principled way to prevent dangerous consequences of the water table decline and reduction of groundwater resources quantity and quality is the correct and systematic use of water and avoidance of uncontrolled groundwater withdrawal.
Maryam Mombeni; Hamidreza Asgari
Abstract
Extended Abstract
Introduction
In recent years, the growth of urbanization in Iran and the increase of migration to the major cities have led to the sudden and abnormal expansion of these cities, degradation of fertile lands and natural resources, and irreparable damages to the nature. As the population ...
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Extended Abstract
Introduction
In recent years, the growth of urbanization in Iran and the increase of migration to the major cities have led to the sudden and abnormal expansion of these cities, degradation of fertile lands and natural resources, and irreparable damages to the nature. As the population of the city of Shushtar has increased, there has been a lot of growth in the built lands in the region, causing a large change in the use of the lands around the city and the degradation of the fertile lands in the suburbs; so that, the continuation of this process could cause irreparable damages to the environmental resources of the region. Land-use prediction models are essential in planning for sustainable use of the lands (Kamusoko et al., 2009: 435, Mas et al., 2004: 94, Sohl and Claggett, 2013: 235). In addition, predicting land use changes and creating a relation between these changes and their socio-economic consequences is very important for sustainable land management (Whitford et al., 2008: 340). So far, the Markov-genetic model has been used in several studies. Wu et al. (2006) studied the monitoring and forecasting of the Beijing region of China over a 16-year period and used the Markov chain model and regression to predict the land use. Therefore, the purpose of this study was to investigate the trend of land use changes over the past years and predicting the land use and land use changes using the Markov chain model in the city of Shushtar in Khuzestan province. By predicting land use variations, the development and degradation of the resources can be identified and it can be led to managing the changes in the appropriate pathways (Brown et al. 2000: 247, Hathout, 2002: 229 and Jenerette et al., 2001).
Materials & Methods
The study area of this research is Shushtar city with an area of 340645.2 hectares located in the North of Khuzestan province. The software packages used in this research include ArcGIS 10.2, ENVI 4.8 and IDRISI Selva 17.0. The images used to extract ground cover classes include Landsat series satellite images; these images were used in this research due to having a long time series, having an appropriate spatiotemporal resolution to study the land cover changes, and being free. Regarding the existing land uses in the region, the research objectives, and the capabilities of the images used to extract useful information, especially the land use mapping, four land uses including rangeland, irrigated agricultural lands, rainfed agricultural lands and residential lands were considered. In the analysis of the Markov chain, the cover classes are used as the states of the chain. To determine the possibility of a change, the chain needs two land use maps (model inputs), which are usually obtained by processing the satellite images (Mitsova et al., 2011: 141). Markov chain analysis was performed using Markov chain order in the Idrisi Selva software. Markov chain analysis is provided for two purposes, the first matrix is used for calibration and the second one is used to simulate the possible changes occurring in the future. The output of the model also includes the possibility of transforming the state, transition area matrix for each class, and at the end of the conditional probability images for converting different uses (Gilks et al., 1996: 19 and Weng, 2002: 273).
Regarding the trend of changes during these three periods, the irrigated and residential lands classes had an increasing state, but on the contrary, rainfed lands and rangelands classes had been decreasing. The accuracy of classifications is generally more than 77%, and suitable for use in the Markov model. The results of the detection of changes in 2030 are such that if the current trend continues in the region, 20.33% will be added to the area of the irrigated agricultural land use, so that irrigated agricultural land use constitutes 60.95% of the area in 2030. This increase is due to the changes of the land uses of rangeland and rainfed to the irrigated agriculture. The decrease in the rangeland and rainfed classes will be 21.12% and 0/21% respectively which will be added to the area of the irrigated agricultural lands. These changes are more pronounced around the rural areas in the region.
Results & Discussion
During the research period, irrigated agriculture has been the most dynamic land use in the region. The area of these lands has increased from 1989 to 2015, so that, 1350131.69 ha has been added to the area of this land use during the three study periods. In the first period, the annual rate of increase was 3650 hectares and in the second period the annual rate increase was 3998 hectares. Considering the lack of change in regional governance and planning, the trend is such, that more than 60 percent of the plain area will be covered by this class in 2030 which can be led to changes in the ecosystem conditions. This result is consistent with the results of Gholamali Fard et al. (2014) in the middle coasts of Bushehr province and is not consistent with the results of Ali Mohammadi et al (2010), Dejkam et al. (2015), and Ramezani and Jafari (2014).
Conclusion
In general, the results of this study indicate an increase in the area of irrigated agriculture, as well as development of the Shushtar, which has occurred through the disappearance of rangelands and rainfed lands. As it is well known, if the current strategy of land use in this area continues to reduce natural lands and increase urban lands, regardless of sustainable development considerations until 2030, significant environmental problems, including degradation of rangeland, decline in production of the major agricultural products of the region, decrease in the fertility, and increase in the deserts, will be a serious threat to the future ecosystem of the region. Also, considering the current productivity status, the region's economy which is based on the agricultural and livestock production will face a serious threat in 2030. Therefore, this research recommends the use of resulting maps to identify the sensitive areas for better planning and management of the executive organizations.
Sharareh Pourebrahim; Mehrdad Hadipour; Mehdi Mardian; Amir Ansari
Abstract
Extended Abstract Introduction Strategic and important industries are established in areas with possible access to water. Industrial development requires abundant water. Analysis of environmental resources and their pollution is the first consequence of industrial and human activities. Therefore ...
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Extended Abstract Introduction Strategic and important industries are established in areas with possible access to water. Industrial development requires abundant water. Analysis of environmental resources and their pollution is the first consequence of industrial and human activities. Therefore today, due to the large volume of discharge and pollution in the environment, direct use of water is neither reasonable nor possible. Discharging industrial wastewater in land could severely contaminate the groundwater. In oil pollution monitoring researches, it is noteworthy that pollution detection and renovation operations require time and economic costs. Contamination of Soil and groundwater with pollutants such as hydrocarbons and chemical solvents has various environmental impacts. In Iran, the concentration of pollutants in some groundwater resources has been reported to be up to three times more than the standard value. This indicates the effect of a large amount of waste in the area which decrease soil quality in a way that soil layers are not able to compensate for it. Therefore, wastewater changes the drainage of underground water resources. In Iran and many other countries, causes such as leakage from contaminated petroleum storage tanks, leakage from transferring lines due to worn pipes, transportation of oil products, etc. in oil extraction mines, and refineries results in groundwater and surrounding areas facing oil leakage. Materials & Methods The purpose of this research is to produce the water quality map of Shazand plain in Markazi province using Geographic Information System (GIS) technique and to investigate the effects of oil industries on the quality of underground waters. The first step is to identify areas affected by these oil industries and identified factors. Appropriate agricultural areas with water supply in the qualitative range were also identified. The location of existing wells in the plain, particularly wells located around the refinery and petrochemical complexes were investigated for the first time. Then, considering the direction of the water land in the plain and the paths of wells located at upstream mountains to downstream ordinary rivers, wells located in the refinery and petrochemical complexes were selected. Accordingly, 14 wells were sampled in the first stage and their coordinates were obtained using GPS. The samples were classified in the laboratory into four groups including physical parameters, chemical parameters, oil and water aromatic parameters and water volatile organic compounds parameters. In the next stage, the maps of water quality parameters zoning were prepared using the "Geostatistical Analyst" developer with the use of the interpolation method of "Inverse Distance Weighting (IDW)". Finally, spatial variations and the groundwater quality changes were investigated. Results & Discussion Oil and aromatic parameters of water are presented along with the results of laboratory analysis in table 2. Results indicate that the numerical value of many parameters were less than 0.1 mg/L. Just two parameters (Anthracene and Pyrene) in well no.10 had a value of more than 0.1 mg/L. Yet, the total value of oil pollutant was quite different. In wells no. 3, 8, 9, and especially well no.10 the value was more than 0.1 mg/L. The zoning map and spatial variation trend, along with statistical-descriptive indexes of total petroleum hydrocarbon of wells were also produced. The spatial variation of oil pollutants in Dashte- Shazand wells in south-north direction showed an increasing trend, which gradually changed into a decreasing trend. A decreasing trend was also observed in west-east direction. Comparing descriptive-statistical indexes with the standard level, we concluded that the total oil pollutant parameter near well no.10, which is located in petrochemical complex faces contamination. Conclusion The present study sought to measure some important indexes of oil contamination in groundwater and surface water near Dasht-e Shazand refinery and petrochemical complex. Therefore, data were collected from 14 wells in the study area. Then, oil and aromatic products were analyzed in laboratory. Using geostatistical technique, spatial variations of quality parameters concentration were investigated and compared with the desired and standard level. Results indicate that most of the wells near Dashte- Shazand refinery and petrochemical complex do not show any sign of contamination. Yet, the concentration of Anthracene and Pyrene parameters in well no.10 is several times more than the standard level. This can increase the potential of contamination in Dashte- Shazand ground water resources. In wells no. 3, 8, 9, and especially in well no. 10, total petroleum hydrocarbon (TPH) was more than other wells. According to the TPH and PAH results, the contamination potential of well no.10 was quite large. Due to the development of Shazand refinery, ground water resources of the area face an increasing danger of contamination. Moreover, the area has a high potential of population increase in residential areas. Thus, water contamination can also endanger the local environment. This shows the necessity of an appropriate management plan and regular monitoring of ground water, surface water, soil and air in the area.
Hassan Emami; Hassan Shahriyari
Abstract
Extended Abstract Introduction Forests play numerous critical roles in nature. They stabilize and fertilize soil, purify water and air, store carbon, and nurture environments abundant in biodiversity. Moreover, forests offer numerous job opportunities and hidden wealth toany economy. Unfortunately, wildfires ...
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Extended Abstract Introduction Forests play numerous critical roles in nature. They stabilize and fertilize soil, purify water and air, store carbon, and nurture environments abundant in biodiversity. Moreover, forests offer numerous job opportunities and hidden wealth toany economy. Unfortunately, wildfires have turned into a serious natural risk nowadays. Wildfires are a natural disaster threatening forests and ecosystem, from local to global level. Evaluating the risk of wildfires is an important factor in fire management. This can be performed at different spatial and temporal scales: global and local; short term, and long-term. At global scales, it can contribute to the establishment of general guidelines for fire management at continental level, while at local scales,it is more suitable for resources focusing on preventing specific fires in small regions. Long-term estimation addresses general, more permanent planning of firefighting resources, which is related to the more structural factors affectingwildfires or their spread, such as topography or terrain characteristics, vegetation structure, human activities or weather patterns. Materials & Methods Wildfire risk has become a major concern in recent years, particularly in areas where human settlements are in close proximity to forests. Wildfire origin canbe determined largely by environmental factors. However, fire related data is either unavailable, or mostly incomplete. Thus, reaching an overall annual estimate of wildfires is difficult. Some common methods are used toestimate the risk ofwildfires, including qualitative methods, quantitative methods based on specialized knowledge (multi-criteria evaluation techniques), regression techniques (linear regression and logical regression), and artificial neural networks. Wildfire initiation and spread depend on several important factors, including precipitation, presence of ignition elements, factors like topography, temperature, thunder, spreading of fuel, relative humidity, wind speed, and etc. The present study integrates data produced by remote sensing with data received from geographic information system. It also takes advantage of LDCM satellite imagery, and digital elevation model, along with natural/human factors such as wind speed and direction, vegetation, land surface temperature, slope, proximity to roads and residential areas. The present study seeks to quantify environmental and human elements effective in occurrence and spread of wildfires in the protected jungles of Arasbaran. To this end, a risk zone map was produced for the area, along with a map for areas with 50% risk. In the present study, the final map of risk zone was produced using the Fire Risk Index (FRI) and spatial statistics method. Results & Discussion In the present study, factors such as land cover type, slope, distance from residential area, distance from the road, and elevation were taken into account. During the process, different indices were assigned to each class of these factorsbased on their sensitivity to fire or their flammability. Land cover was one of the most important factors affecting the occurrence of wildfires. Slope was another important factor with a significant influence on the spread of fire. This natural factor affects fire spread and fire intensity. Proximity of human settlements to jungles is another important factor which sometimes threatsjungles. Therefore, forests in proximity of human settlements face a higher risk of wildfires. Elevation is another important topographical factorclosely related to wind behaviour, with a significant role in fire spreading. In Arasbaran forest, northern, eastern, and north-easternareas are more elevatedand thus, more prone to wildfires. In this study, a combination of environmental and human factors was applied to produce fire hazard maps along with a map for areas with 50% risk of wildfire. Conclusion Occurrence and spread of wildfires depends on many factors, some of which are more important and play a more significant role in these fires. A risk zone map was produced for wildfiresusing an integrated method consisting ofremote sensing and GIS methods. Risk zone was divided into 5 areas, i.e. very low, low, average, high, very high.Results indicate that the methodology presented based on a combination of RS and GIS techniquesin this study, is a reliable approach and tool for the prevention and mitigation of forest fires. They are also useful for all active institutes working in crisis management and emergency services, while helping jungle protectingorganizations to prevent fires or manage them. In addition, quantitative results indicate that vegetation index with a correlation of 58.36%, and slope with a correlation of 38.38 are the most affective factors, and other parameters are in the next ranks.Moreover, land cover, land surface temperature, direction, and slope with 29.20%, 29.11%, 21.93% and 19.75% normalized correlation coefficient respectively, have the highest correlation with the map of fire risk zone. In addition, results of evaluating 50% risk zone map indicate that around 17% of the study area have a high fire risk and more than 50% of the area is located in a high fire risk zone. In addition to environmental elements, results indicate that proximity to the road was the most affective factor in the occurrence of fire. Quantitative results showed that roads and residential areas were at least 32% and at most 68% correlated with fire risk in the study area.
Mohsen Ahad Nejad Roshti; Shahrivar Roustaei; Mohammad Javad Kameli far
Abstract
Urban road network is one of the most important urban arteries which has a significant impact on the relief and rescue operations, the evacuation of the injured and harmed people, especially after the crisis. Therefore, assessing the vulnerability of urban road network and planning to reduce these ...
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Urban road network is one of the most important urban arteries which has a significant impact on the relief and rescue operations, the evacuation of the injured and harmed people, especially after the crisis. Therefore, assessing the vulnerability of urban road network and planning to reduce these harms is necessary. This descriptive-analytical research was conducted with the aim of evaluating the urban road network against earthquake by crisis management approach in region 1 of the city of Tabriz. In order to assess the vulnerability of urban road network of Tabriz region 1, three criteria of confinement degree, density, and constructional characteristics were selected. The density criterion includes the sub-criteria of population density and constructional density and the criterion of building characteristics includes five sub-criteria ofage of the building, the quality of the building, type of use, occupation level and type of materials. Each one of these sub-criteria has several sub-criteria as well, which were evaluated by Delphi method. Finally, after assessing the vulnerability of the roads in each sub-criterion, the layers were overlaid by the Multi-criteria Evaluation (MCE) method in the form of IDRISI software. The final results indicate that the vulnerability of the study area roads network (excludingthe newly built neighborhoods) is more than moderate, and is mostly high and very high.The vulnerability of the roads networkis more common in informal residential neighborhoods which should be considered as a priority in planning.
Ali Kalantari Oskouei; Mahdi Saber Khoshemehr
Abstract
Extended Abstract Introduction Data sharing is one of the key issues in the success of Spatial Data Infrastructure (SDI). Data sharing can prevent the repeated production of spatial data by various organizations and institutions, and provide the reduction of the costs, prevention of the resource losses, ...
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Extended Abstract Introduction Data sharing is one of the key issues in the success of Spatial Data Infrastructure (SDI). Data sharing can prevent the repeated production of spatial data by various organizations and institutions, and provide the reduction of the costs, prevention of the resource losses, helping the economic development and using the capabilities of spatial data in processes of decision-making. But, evidences suggest that the realization of the spatial data sharing has always faced numerous challenges and problems, and that the SDI development goals will not be achieved without solving them. Therefore, the main objective of this research is to provide a strategy for identifying and prioritizing the sharing of spatial data in the country. Materials & Methods The framework of the research is based on surveying, the concept of risk, and the use of a fuzzy inference system. In order to objectify this framework, a case study was conducted with the participation of 19 organizations in East Azarbaijan province. At first, various sources were reviewed and the 25 probabilistic sharing challenges were identified. Then, with the help of a questionnaire, experts’ viewpoints regarding the probability of the occurrence and severity of the impacts of the challenges were investigated. The questionnaire consists of two parts. The first part focuses on the demographic information of the experts such as affiliation, years of experience, and academic degree, which were used to determine the experts’ importance weight. The second section measures the probability and the impact intensity of each identified challenge. To measure the factors of probability and impact intensity, a five level verbal rating scale including, very high, high, medium, low and very low (as verbal terms) was used to maintain the balance between simplicity and comprehensiveness. In the next stage, a fuzzy inference system, with two inputs and one output, 25 fuzzy rules, Guassian membership functions and the field inference engine were developed to process the views of the experts and to calculate the fuzzy scores of each of the challenges using MatlabR software. Having determined the sharing challenges scores, a cluster analysis was carried out to divide them based on the score related to the groups (clusters), so that, the challenges inside a cluster are very similar (but not identical) to one another but very different from the challenges in other clusters. Since there is no need to specify the numbers of clusters in hierarchical methods in advance, the hierarchical method was used as a clustering technique to group the challenges. Then, the results were evaluated by a number of knowledgeable experts. Results & Discussion According to the findings, the most important challenges which had the highest scores and were also in the same cluster, include: lack of a Geoportal for searching, access and evaluation, lost problems or metadata, lack of coordination among different organizations for spatial data sharing, fear of disclosing of organizational spatial data and information, the lack of up-to-date spatial data and information, the tendency to parallel work (the lack of investigation of other organizations for spatial data and information needed by the organization) and the lack of specialist in spatial data and sharing the information. Moreover, 25 challenges of spatial data were categorized into five homogenous groups (clusters) by applying a hierarchical cluster analysis. Based on the results, the overall geometric mean value of the 25 challenges of the spatial data and information sharing was calculated as 62.76% that shows the existence of the important challenges in the realization and implementation of the spatial data sharing and SDI initiatives in organizations. Analyzing the results with regard to the two types of sharing challenges revealed that the organizational challenges with a geometric mean of 55/56% were more important than the technical challenges with a geometric mean of 44/44%. These results may mean that, in order to overcome the organizational challenges, more time and efforts have to be taken into consideration in the planning and development of SDI compared to the technical challenges. Conclusion It seems that there is no accurate and complete picture of the concept of the spatial data sharing in the majority of the organizations, and it is often interpreted as putting spatial data and information of the organization in the hands of others. However, a significant part of the sharing issue is associated with the metadata sharing that prevents the repeated works and spending unnecessary credits of the organizations, and make the available data to be accessible with spatial services in different formats after an agreement between data providers and consumers, and to be used in decision making processes. The information gap in this regard is very tangible in the organizations, nevertheless, it would be possible to change the views and behaviors of individuals and organizations by creating capacity, and eventually to be hopeful that the willingness of organizations to participate in data sharing improve. Finally, the following recommendations were suggested in order to improve the status of the data sharing: individual and organizational attitude changes towards the issue of data sharing, increasing technical knowledge and empowering organizations in spatial technologies and clarifying the benefits of spatial data sharing and its socioeconomic roles in society, specifying the leader organization and forcing organizations to create standard spatial databases and metadata.
Hossein Hataminejad; Ahmad Pourahmad; Morteza Nosrati Heshi
Abstract
Introduction Neighborhoods that have once lied at the heart of cities and enjoyed cultural richness, now face a problem called "worn-out and inefficient urban texture". New needs emerged and old urban textures faced physical-spatial defects. On the one hand, physical decay, social and economic life in ...
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Introduction Neighborhoods that have once lied at the heart of cities and enjoyed cultural richness, now face a problem called "worn-out and inefficient urban texture". New needs emerged and old urban textures faced physical-spatial defects. On the one hand, physical decay, social and economic life in problematic and ineffective textures have exacerbated the deterioration of urban life quality and degraded urban ecosystems in old urban textures of Iran. On the other hand, with rapid scientific and technological advancement in the contemporary world, urban planning system has also undergone transformations and the effects of such changes can be challenging for the city progress. Today urban planning, previously based on traditional system, seems to lack the power and the ability to respond to and solve problems of worn-out urban textures. Therefore, by identifying the opportunities and threats of the future of these textures, ‘futures studies’ approach will help us to better utilize future opportunities and prevent the negative consequences of old urban textures as much as possible. Thus, the most important issue in studies focusing on the future of this part of urban context is the consideration of other factors, including human factors (residents, owners, beneficiaries, and stakeholders) and their contribution to the long-term planning process. The general purpose of futures research is to create awareness about the external environment in order to understand the gaps, trends, and developed technologies. In this way, we can improve the environment as much as possible. Materials and Methods The present study sought to identify the key variables in reducing worn-out urban texture and to examine the relationships between these variables and their influence on each other in the time horizon of 2037. Therefore, using environmental scanning technique (reviewing articles and other published resources, interviewing experts and monitoring conferences) and examining related literature, the initial and existing variables (160 variables) were extracted from the worn-out texture of the 9th district (1st area). The dominant process in this research is applied in terms of purpose, and descriptive-analytical in terms of research method. The nature of data is qualitative. Data were collected from library sources using documentary and survey methods. Since, it is very difficult and even impossible in some cases to manually calculate the cross-impact matrix, complex calculations and data analysis were performed based on the cross-impact analysis method, using Micmac analysis software. Discussion and Results Organizing two consultative workshops with experts and managers of worn-out texture, information and variables were integrated, resulting in 61 variables classified into six sub-categories of economic, social, cultural, managerial, legal and legislative, physical, and political. Thus, in order to extract the main factors affecting the reduction of worn-out textures of the area in the horizon of 2037, we entered each variables using Micmac software. Cross-impact analysis matrix (61*61) was created and the degrees of mutual influencing and impressionability were evaluated and ranked by experts and practitioners. In order to arrive at a reliable coefficient of the data validity, the number of iterations was increased up to 5 times to reach one hundred percent desirability and optimization of the matrix. By analyzing data using the software, research results indicate that key strategic and most influential variables for reducing worn-out texture in the 1st area of 9th district are "changes of the government " (the comingup of the new government every four years), "lack of specific laws regarding worn-out texture and their organization", "balancing and realizing social justice", "weakness of attitudes and knowledge in urban managers" and "establishment of organized and continuous local organizations to encourage residents to participate". Conclusion Based on the research findings, it can be concluded that only two key and strategic variables (i.e. "changes of the government in every four years" and "good urban governance”) in the 1st area of the 9th district of Tehran played a determinant and influential role. These were considered to be the key players in the system. Therefore, adopting a comprehensive and far-reaching approach to the future of worn-out textures seems to be vital and necessary.
