Extraction, processing, production and display of geographic data
Ali Hasankhani; Mahdi Modiri; Ahmad Naghavi
Abstract
Extended AbstractIntroductionUnfortunately, seismic data recorded globally during the last fifty years does not include every type of wave propagation conditions in the environment, types of construction, the rupture process on the fault, and the geometrical relationship between the construction and ...
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Extended AbstractIntroductionUnfortunately, seismic data recorded globally during the last fifty years does not include every type of wave propagation conditions in the environment, types of construction, the rupture process on the fault, and the geometrical relationship between the construction and the fault. This is especially seen in near-field regions. Before the 1999 Chi-chi earthquake in Taiwan and the 1999 Izmit earthquake in Turkey, there were only about 20 records of earthquakes with a magnitude greater than 7 at a distance of less than 20 kilometers from the fault.The Turkish earthquake added 5 records and the Thai earthquake added 65 records to this collection, but only two fault rupture scenarios were added to our knowledge, while thousands of other possible scenarios may occur. Thus, seismologists and earthquake engineers have tried to estimate parameters related to strong near-field motions of the earth with an acceptable confidence using various experimental and theoretical simulation methods. MethodsIn earthquake engineering and seismology, earthquake phenomenon and the resulting movements are generally investigated and analyzed using dynamic and kinematic methods. Seismological models and problems are thus divided into two categories: Kinematic models which are based on slip distribution and do not take the state of stress on the fault into account. Dynamic models deal with the physics of fault rupture and its causes. Simulation methods are also divided into three main categories: deterministic (low frequencies), stochastic (high frequencies) and hybrid (broad band) methods.Generally speaking, simulating strong ground motion plays an important role in the estimation of related parameters especially in regions lacking such data. Accelerographs are used to simulate strong ground motions. The present study has introduced, investigated and validated two methods: decisive simulation models (Discrete-Wave Number and Finite Fault) and Finite Fault models. It also explains how the simulated recording are produced for near-field (less than 20 km to a seismogenic fault) and far-field events, presents attenuation relationships for the Zagros seismotectonics region, and predicts parameters of strong ground motions.Results & DiscussionDue to the special geological conditions and the existence of many active faults in Iran, our country is considered to be located in an earthquake-prone region. Zagros region is considered to be the most earthquake-prone region of Iran. Finite fault modeling combines various aspects of plate source with the ground motion model based on point source. Since previously mentioned limitations are not naturally present in finite fault modelling, the method takes geometry of the fault and the directivity effect into account. Time delay method and the sum of accelerations recorded in maps of a two-dimensional network are used for simulation in finite fault model. The fault plate is divided into various elements and a minor event is simulated for each one. The overall seismic acceleration equals the sum of the effects of these minor events. The strong ground motions in each micro-fault are calculated using the random point source method and then summed up at the desired point with an appropriate time delay to obtain the ground motion of the entire fault.Previous geological and seismic studies of each seismic region are used to determine the key parameters of the simulation input. To produce a comprehensive database, a significant number of stations are taken into account around the fault based on different hypotheses and artificial accelerograms are produced in accordance with the seismological parameters of the region. A suitable function is then selected and an attenuation relationship is fitted. The simulation results and the resulting attenuation relationship are then compared with valid global attenuation relationships and their consistency (compliance percentage) is investigated. ConclusionThe present study has produced a wide range of simulated records (about 20 thousand records) for Zagros seismotectonics region. Thus, the resulting relationships will hopefully have sufficient accuracy and efficiency to be used in structure designing and urban development. It worth noting that the regression correlation coefficient (R-Square) was above 0.95 in all fits.These attenuation relationships can provide a new perspective on site selection, and help us in understanding the dynamic behavior of structures, and the development of various infrastructure. They also help urban managers to predict and reduce earthquake damages.
Geographic Information System (GIS)
Mohammad hassan Yazdani; Ata GhaffariGilande; Farahnaz Veismoradi
Abstract
Extended Abstract1-IntroductionA crisis is a crisis that threatens our country due to special geographical conditions. According to official statistics in the last 29 years, 1% of the country's human casualties were caused by earthquakes, and on average every year an earthquake with a magnitude of 7 ...
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Extended Abstract1-IntroductionA crisis is a crisis that threatens our country due to special geographical conditions. According to official statistics in the last 29 years, 1% of the country's human casualties were caused by earthquakes, and on average every year an earthquake with a magnitude of 7 on the Richter scale occurs in the country for 11 years (Attar), 2012: 8).From the point of view of geology, Iran has a zone of lithological structure such as Central Iran, Zagros, Northeastern Iran, Northwestern Iran and Azerbaijan zone, which the thrust and elevated structure of Zagros is considered as one of the most active of these zones. It includes faults such as Sahne, Durood, Qala Hatem. The seismic characteristics of Zagros show that compared to other structural zones, the frequency of earthquakes is high. The central Iranian and Arabian plates are constantly pressing on the Zagros region, and this is the reason why more earthquakes occur in Zagros than in other regions. The studied area of Kermanshah region is an earthquake zone in terms of seismicity. This province, which is located in the Zagros region, has high seismic activity. These earthquakes usually occur around known seismic faults in the province, including the High Zagros Fault (High Zagros Fault, 2014: 114). Despite numerous researches in the field of locating temporary accommodation on the subject of seismic vulnerability, its suitable and usable place after the earthquake with the approach of crisis management in urban areas has received less attention. The city of Kermanshah is a prone region in terms of earthquakes, and due to its location in a geographical area with a high risk of earthquakes, knowing the vulnerable and resistant areas and planning for the correct and appropriate location of temporary accommodation in time The occurrence of an earthquake is necessary to prevent or reduce the possible danger in this city. This research is complementary to the previous research and with more effective criteria and indicators by providing a practical, efficient, simple and logical method for locating temporary accommodation in order to prepare the city with their specific complexity in responding to crises caused by earthquakes. Is. As an example, the Ezgele earthquake in Kermanshah in 2016 with a magnitude of 3.7 on the Richter scale occurred 11 km from Ezgele section and 32 km from Sarpol-Zahab city, which killed and injured more than 12 thousand people. And since then, due to the lack of single policies in the field of emergency, temporary and permanent housing, problems have been created for housing people. Therefore, the existence of a suitable place to live in Sharat after natural hazards, especially earthquakes, is essential for the city of Kermanshah. The present study, taking into account the stages of crisis management of an earthquake-prone city, tries to address the problem of locating suitable spaces for the construction of temporary accommodation camps.2-MethodologyThis research is of an applied type and according to the investigated components, the approach that governs it is the descriptive-analytical method. The aim of the present research is to analyze the important and influential criteria for the correct location of temporary accommodation in Kermanshah city. In order to achieve this goal, in accordance with the objectives of the research, the required information has been collected using library research, documents and interviews with experts, and then the criteria used for positioning have been selected based on the positioning criteria. The current approach to spatial analysis has been carried out by using the weighted sum model and the ranking method and ArcGIS software.3-Results-Road situation: The analysis of the results of the Kermanshah city situation based on the road access index using GIS analysis software shows that 75% of the city is in the very low vulnerability zone, 7% is in the low vulnerability zone, and 5% is in the vulnerability zone. On average, 3% is in the high vulnerability zone and 10% is in the very high vulnerability zone.-Population density: Examining the results of the state of Kermanshah city based on the population density index using GIS analysis-mapping software, shows that 27% of the city is in the very low vulnerability zone, 27% in the low vulnerability zone, 26% in the medium vulnerability zone. 11% is in the high vulnerability zone and 10% is in the very high vulnerability zone.-Location to administrative, law enforcement and military centers: Examining the results of Kermanshah city status based on the index of access to administrative, law enforcement and military centers using GIS software, shows that 7% of the city area is in the very low vulnerability zone, 12% in the vulnerability zone low, 13% in the medium vulnerability zone, 12% in the high vulnerability zone and 57% in the very high vulnerability zone.-The location of fire stations: the analysis of the results of Kermanshah city based on the index of access to fire stations using GIS analysis software shows that 2 percent of the city is in the very low vulnerability zone, 5 percent in the low vulnerability zone, 8 percent in In the medium vulnerability zone, 32% is in the high vulnerability zone and 53% is in the very high vulnerability zone.-Land slope: This criterion is measured by the slope index. Examining the results of Kermanshah city status based on the land slope index using GIS analytical-mapping software, shows that 46% of the city area is in the very low vulnerability zone, 33% in the low vulnerability zone, 11% in the medium vulnerability zone, 6% in the vulnerability zone. high and 4% is in the zone of very high vulnerability.-Distance from flood-prone areas: The evaluation of the results of Kermanshah city status based on the index of distance from flood-prone areas using GIS analysis-mapping software shows that 16% of the city area is in the very low vulnerability zone, 11% in the low vulnerability zone, 19% in the low vulnerability zone. In the zone of moderate vulnerability, 25% is in the zone of high vulnerability and 29% is in the zone of very high vulnerability.-Distance from hazardous facilities: To measure this criterion, the indicators of electrical facilities, gasoline pumps, gas pumps and gas pressure reduction stations have been used in terms of their functional nature and hazard. Analyzing the results of the state of Kermanshah city based on the index of distance from dangerous facilities using GIS analytical-mapping software, it shows that 13% of the city area is in the very low vulnerability zone, 12% in the low vulnerability zone, 25% in the medium vulnerability zone. 34% is in the zone of high vulnerability and 16% is in the zone of very high vulnerability.-Status of water sources: The results of Kermanshah city situation based on the index of access to water resources using GIS analysis-mapping software show that 9% of the city is in the very low vulnerability zone, 17% in the low vulnerability zone, and 15% in the vulnerability zone. On average, 32% is in the high vulnerability zone and 27% is in the very high vulnerability zone.-Location to power sources Construction of camps and temporary accommodation sites in the power transmission routes due to the provision of lighting and the use of heating devices. The evaluation of the results of the status of Kermanshah city based on the index of access to electricity resources using GIS analytical-mapping software shows that 9% of the city area is in the very low vulnerability zone, 8% in the low vulnerability zone, 8% in the medium vulnerability zone, 26% in The zone of high vulnerability and 49% is placed in the zone of very high vulnerability.-The final map of the optimal location of temporary accommodation bases after defining the important criteria and analyzing the indicators in the studied area is as follows: The results of the combination of 9 indicators in the city of Kermanshah indicate that 1% of the city area In the area of very low desirability, 11% is in the area of low desirability, 37% is in the area of medium desirability, 38% is in the area of high desirability, and 13% is in the area of very high desirability.4-Discussion&ConclusionsIn this research, according to the nature of the research and examination of the environmental conditions of Kermanshah city and the important indicators that are selected and evaluated according to the topic. After examining the determining and influencing factors on the temporary accommodation system and identifying the factors, the results were 9 indicators, which should be applied in the present study with general and specific evaluations (relative to the conditions of the study area). It became a scientific source of consolidation. Investigating and identifying the most accurate features in choosing the location of safe shelters: (slope, access to roads, distance from centers and management, access to firefighting centers, access to water and electricity sources, distance from flood-prone areas, and distance of dangerous risks) is considered And the results of the research showed that the important criteria and options in choosing the right place for temporary accommodation are centers that are identified as the best places that are far from the river and sensitive and dangerous uses such as gas stations and pressure lines. It should be maintained strong and close to essential service centers such as medical centers and fire stations, provided with water and electricity sources, accessible by communication lines, and the probability of damage and blocking of roads should be low. Examining the points selected in the final map shows that in the city of Kermanshah, these points are suitable for use according to important criteria such as: accessibility, distance from sensitive uses, proximity to service areas and distance from flood prone areas. It is in critical condition. The results of the current research show the capability of multi-criteria decision-making methods and geographic information system in identifying areas prone to temporary settlement. Therefore, according to the findings and results of this research, it is suggested that relevant organs, departments and organizations such as the municipality, the governorate, the crisis management center of the Kermanshah Fire Organization, etc., by creating comprehensive and updated databases of all details and elements A city based on the geographic information system should always be prepared for the temporary settlement of the population in the wake of the earthquake crisis. -Preparation of basic and suitable infrastructures for selected sites such as sanitary facilities, water sources, lighting system, etc., so that in case of an earthquake, it has the necessary conditions to accommodate the population, and the need to spend time for not provide these services. Accommodation centers should be located near roads that provide access to different parts on the one hand, and on the other hand, the probability of damage and blockage of these roads is low so that the risk of cutting off access, accommodation, relief and rescue operations does not stop. Zagros seismic zone has its own seismic mechanism. The fault systems and the earthquakes that occurred there follow the special pattern of the Zagros earthquake province, so planning and management should be done by evaluating the existing conditions and taking into account all the conditions of the region and the needs of the people. be carefully examined.
Reyhaneh Modirzadeh; Rashed Emami; Sayad Asghari Sareskanrod; Aref Rostami
Abstract
Extended Abstract
Introduction
Earthquake is a natural disaster which sometimes causes injury and loss of life to many people and generates tsunamis. As one of the most frequently occurring natural phenomena, it is considered by many as the most frightening and dangerous natural hazard. With recent ...
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Extended Abstract
Introduction
Earthquake is a natural disaster which sometimes causes injury and loss of life to many people and generates tsunamis. As one of the most frequently occurring natural phenomena, it is considered by many as the most frightening and dangerous natural hazard. With recent developments of remote sensing, radar interferometry is accepted as an efficient and relatively accurate method of measuring ground surface displacement. The present study has investigated June 25, 2020 earthquake in Qotur (the city of Khoy).
Materials & Methods
The present study have utilized InSAR and PSI techniques to estimate the amount of displacement caused by the earthquake. Remotely sensed images collected in the upstream passages were processed in Sarproz software. Radar interferometry and other advanced methods such as PSI have made detection of vertical surface displacements possible even in a few millimeter range. The present pairs of images have been selected with a good correlation from Sentinel-1 data.
Results & Discussion
The present study seeks to estimate the extent of ground heave and subsidence caused by earthquakes. Images selected from statistical periods before and after the earthquake were processed, and outputs were presented as figures and diagrams. Graphs showed the accuracy of the work and annual cumulative displacement. Results indicated the presence of a surface displacement between -16 and +16. The most intense subsidence and ground heave have happened in the northeastern regions (Gogerd village) and the southern regions (Kotanabad, Mir Omar, Grenavik villages), respectively.
Conclusion
Maximum displacements (heave and subsidence) and other data collected from the earthquake show that the Bashkala left-Lateral Strike-Slip fault has caused this earthquake.
Esmaeil Aliakbari; Mostafa Taleshi; Mohammadreza Karami; Kioumars Maleki
Abstract
Introduction
On average, an earthquake with the force of 6 magnitude of the Richter scale hits Iran every year and a 7.0 earthquake strikes the country every ten years. The fact that urban areas face serious damages due to these natural disasters makes it clear ...
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Introduction
On average, an earthquake with the force of 6 magnitude of the Richter scale hits Iran every year and a 7.0 earthquake strikes the country every ten years. The fact that urban areas face serious damages due to these natural disasters makes it clear that a crisis plan is quite necessary. City is a multi-layered structure consisting of closely related physical and non-physical components (functional, spatial, and social) with two levels of interaction among them. Providing a clear understanding of the consequences of hazards and evaluating vulnerable urban areas seem to be a necessary step toward decreased vulnerability to natural hazards. This will be definitely reached through policy making, making the right decisions and taking the right actions. The present study seeks to analyze zoning and vulnerability of Kermanshah metropolis in regard to possible earthquakes. Findings of the present study can be used to prepare an appropriate plan for the future of this city. The present study also explains physical, social and natural components, and uses a combination of these components to prepare different quantitative models and the necessary indicators (basic studies). It also attempts to provide methods of implementing these models and indicators (operational methods). And finally it seeks to prepare a hazard map to facilitate the identification of critical areas and impenetrable residential zones in Kermanshah metropolis, while determining optimal directions for future physical-spatial development of Kermanshah based on seismic risk zone. This is achieved through a new approach using Analytic hierarchy process.
Methodology
GIS and multi-criteria decision making methods are used in the present study for seismic zoning of natural, physical, social, and economic dimensions of Kermanshah. To reach this end, statistical, non-statistical and online sources were used and necessary maps were collected from relevant organizations and departments. In general, 1, 25000 topographic maps (AutoCAD Versions), Parcel maps of the 2016 census, land use maps showing the present situation (AutoCAD Versions), and etc. were used in the present study. Except for parcel map which was prepared in Shapefile (a well-known format prepared in ARCGIS software) and thus ready for GIS analysis, other layers were prepared in CAD format and had to be edited, revised, and then converted to Coverage format and Shapefile for final editing in GIS models. It is noteworthy that many of these maps were completed and edited by the authors. Then, maps required for each cluster were standardized using the classification method. Related weights and pairwise comparison matrix were defined for each cluster using scientific resources.
Results and Discussion
Due to the large number of sub-indicators used in the present study, each indicator was rated and graded separately. Results indicate that Kermanshah metropolitan area enjoys a desirable status regarding the economic indicator since69.6% of the city lies in the low vulnerability range of this indicator. Regarding the social indicator, the city is in an unfavorable status since56.6% of its area lies in a very high vulnerability range and only a small percentage of the city area (1.5%) lies in the low vulnerability range. Regarding the physical indicator, 57% of the city lies in the medium vulnerability range and 33.2% in the low vulnerability range. Regarding the natural indicator, 55.4% of the city lies in the medium vulnerability range, 36.5% in the high vulnerability range, 1.8% in the very high vulnerability range, and 6.3% in the low vulnerability range. The unfavorable status of the social indicator is due to the presence of areas facing high or very high levels of vulnerability. Findings of the economic indicator imply the distribution of an economic class with an average income in the city. Regarding the physical indicator, about 30% of the city area is covered by old vulnerable settlements constructed with unsustainable materials in direct contrast with urban planning rules. These areas require improvement, reconstruction, and renovation. Regarding the natural indicator, Kermanshah and its neighboring cities are built on earthquake fault lines. Dealing with this situation requires strengthening and modernization of old urban contexts, increasing permeability of arterial roads, development of non-physical spaces, making a greater use of empty spaces, and building new residential spaces (brownfield lands). Findings indicate the significant role of natural factors (including proximity to earthquake fault lines), physical factors (old contexts, inefficient materials, and etc.), and above all, lack of engineering supervision in the present constructions of the city. Land uses facing earthquake hazards in Kermanshah include residential (about 16% located in the very high vulnerability range), road network (about 15% located in the very high vulnerability), and emergency operation, military and medical centers. This will definitely jeopardize any rescue operation in possible future earthquakes.
Conclusion
Earthquake and its related devastating mechanism constitute a very complex process in which various factors play a role. These factors can reduce destructive effects of earthquakes on urban settlements. High population density, patterns of spatial distribution, vast man-made environment and different characteristics and conditions of its constructions have made analyzing the situation if not impossible (without computer and advanced software), quite difficult. The present study has analyzed different indicators and sub-indicators, and introduced inappropriate status of physical elements, inefficient road network, overcrowded and worn-out urban fabric in the city center, high density, and inappropriate distribution of open and green spaces in the city as the key factors resulting in increased vulnerability of land uses in the current zoning of the city. Due to the close relationship between damages of an earthquake and proximity to earthquake fault lines, development of a physical-spatial model in Kermanshah metropolis before the occurrence of future earthquakes seems necessary. Results indicate that in case rules and principles of urban planning are followed, endogenous and horizontal development of the city toward southern and northwestern direction seem to be logical. Furthermore, considering factors such as slope, slope direction and the east-west direction of faults, development of the city toward west or east is not recommended unless principles of urban planning and reinforcing is completely followed. Rough and rugged topography of the northern and northeastern parts of the city is also another obstacle to the physical development of the city in these directions. Therefore, physical-spatial development in the southern and southwestern direction, along with infill and endogenous development according to the potential of the city are recommended
Yasser Ebrahimian Ghajari
Abstract
Introduction Natural hazards have always been a part of our surrounding environment and human life would be unimaginable without considering these hazards. With the development of social life, and particularly with urbanization and increasing expansion of cities, the dimensions of such incidents have ...
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Introduction Natural hazards have always been a part of our surrounding environment and human life would be unimaginable without considering these hazards. With the development of social life, and particularly with urbanization and increasing expansion of cities, the dimensions of such incidents have become more complicated. Earthquake is one of the most important natural hazards that takes the lives of many people every year. Although definite prediction of earthquake is not still possible, high-risk areas can be identified by zoning earthquake hazard using new technologies such as GIS, and measures can be taken to deal with the critical situation of identified regions during an earthquake. Planning of temporary accommodation with the aim of crisis management and reduction of secondary damages caused by the earthquake have always been amongmajor concerns of urban planners and managers. In the past, the policy of creating temporary accommodation centers and disaster relief sites lacked a specific program, so that locating a vacant land, with no owner was the most important principle for the creation of these centers in urban areas. It is now proved that these methods lack efficiency. However, recent advances in modern technologies such as GIS have improved planning process. This kind of planning procedure takes effective parameters and criteriainto account, many of which have spatial nature. Urban resiliency is one of the most important branches of urban crisis management, thus risk assessment and risk reduction planning, including site selection for temporary accommodation (as a principle of urban resiliency),are highly essential. Materials and methods The study area of the present research is Babol, one of the major and central cities of Mazandaran Province. Babol is located in BabolCounty, 14 km from the Caspian Sea and 10 km from the Alborz Mountains. With a total area of approximately 32 km2 and a population of250,217 (at the2016 census), it is the second most populous city in Mazandaran province.The 600 km long Caspian faults and 680 km long Alborz faults are among the effective faults of the study area. In the present study, effective measures for selectionof temporary accommodation siteswere extracted and weighted using expert opinions specialized in structural engineering, earthquake, urban planning, crisis management, passive defense, traffic and transportation. Identified criteria included distance from the river, distance from the fault, land use, distance from installations network, access to the transit network, distance from fire stations, population density, distance from tall buildings, distance from police stations and distance from health centers. Then, using GIS analytic functions, standard maps were produced and combined to identify the best areas for temporary accommodation (after a possible earthquake) in Babol. Criteria were weighted using fuzzy analytic hierarchy process and weighted overlay method was also used to combine them. Results and discussion Analyzing the results indicated that only 7% of the total study area (Babol City) is appropriate for temporary accommodation. Identified areas were examined according to other temporary accommodation standards. Finally, six sites and a total of 107 hectares (less than 4% of the study area) were identified as suitable sitesfor temporary accommodation. With a very large area (37 hectares) and full access to water, electricity and gas facilities,the first site is locatednear eastern beltway of Baboland Lotus PondRecreational Complex. The second proposed site is a 11-hectarevacant arealocated in the northeastern part of Babol City, between Ramenet and Pari Kola Villages. With a total area of 22 hectares,the third proposed site is located in the south-east of Babol City and near Babol-Qa’emShahr Road. Unlike the previous three sites, the fourth proposed site is located almost inside the city. It is a vacant 5-hectarearea in the northern side of the Motamedi Martyrs’ Cemetery. The next site, also located inside the city, is Aminian Dormitory (Noushirovani University of Technology) with a total area of 4 hectares. Although the last proposed site was ranked lower than the other five sites in the final analysis, it has the highest score among available sites inwestern side of Babol river. With a total area of 28 hectares, this site is located within a short distance of Imam Khamenei Highway. Conclusion According to the international standards, per capita area for temporary accommodation is approximately 4 m2. Therefore,with a population of about 250,217,Babol needs an average space of 100 hectares for temporary accommodation. Although, the proposed space for temporary accommodation (107 hectares) in Babol almost equals the required space (100 hectares), with the present rate of population growth inBabol, increasedconstructions, and consequently, reduction of appropriate space for temporary accommodation, Babol will definitely face a shortage of suitable space for temporary accommodation of earthquake victimsin near future. Moreover, the spatial distribution of suitable sites for temporary accommodation is not reasonable, as most of the suitable sites are located in the eastern part and within the boundaries of the city. While, these sites are expected to be scattered throughout the city with an equal access for all residents.Finally, it can be concluded that temporary accommodation of earthquake victimswas not considered in urban planning of Babol, and as a result, the city does not have a suitable status regarding temporary accommodation of earthquake victims.
Zohreh Fanni; Seyyed MohammadReza Ghashami
Abstract
Extended Abstract
Introduction
The natural behaviors of the human life environment where the settlements are constructed without recognizing and studying these behaviors are called hazards. The distinctive features of natural hazards are the changes in the hazard severity in different locations, as ...
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Extended Abstract
Introduction
The natural behaviors of the human life environment where the settlements are constructed without recognizing and studying these behaviors are called hazards. The distinctive features of natural hazards are the changes in the hazard severity in different locations, as in the urban environments, human activities along with greater vulnerability in the environment, aggravate the hazard and the extent of its occurrence. The city and its infrastructure development in providing security and various needs of human are of the most substantial areas for the development of social life. In general, identifying areas prone to hazards is a key tool for decision makers to reduce the damages caused by natural hazards. On the other hand, abstract study of the nature’s behaviors in the form of flood, earthquake, land slide and subsidence has always made managerial decision-makings difficult, so that avoiding the aggravating factors of a hazard has caused to get close to another hazard.
Objectives
The main objective of this study is to evaluate areas affected by these four natural hazards in all 22 Districts of Tehran City. In other words, this research with the aim of comprehensive and integrated zoning of hazards such as flood, earthquake, landslide and subsidence has proceeded to identify, evaluate and adjust the findings in the form of a comprehensive map of the susceptibility of these behaviors under the title of four environmental hazards within the 22 districts of Tehran city.
Discussion
Multiple-risk analysis, including a range of data, provides a more realistic model of the natural environment management. In this regard, studies have been conducted on the various approaches to analyze spatial data, how to create a combination of environmental hazards and how to determine their risk and vulnerability levels. To generate a probabilistic model, the basic assumption is that the risk level is determined by risk factors and possible hazards in the future, and with an emphasis on the past events. In this study, the creating and effective factors in environmental crises are related and calculated with each other with respect to several risks.
Research Methodology
One of the usual algebraic methods is the Analytic Hierarchy Process (AHP), which, as a weighted evaluation method, evaluates different scenarios and selects the best option by combining the qualitative and quantitative factors. The Analytic Hierarchy process as one of the multi-criteria decision-making methods provides the ground for performing applied spatial analyses by examining the effects of different factors in contradiction with each other. The research method is quantitative-analytical, and all the factors affecting the occurrence of each hazard have been identified and digitized in ArcGIS environment and modeled using Frequency Ratio (FR) model. Then, each of the four susceptibility maps was combined in fuzzy method and the final susceptibility map was classified into 5 classes of very high, high, moderate, low and very low susceptibility, and was extracted and presented as a map and a table.
Results
This research resulted in the production of the susceptibility zone map for more probable hazards including flood, earthquake, landslide, and subsidence of Tehran City in the separation of 22 Districts. This map includes several factors such as slope degree, slope direction, slope shape, elevation layers, distance from the river, distance from the road, distance from the fault, geology, land use, and the rain The result show that the effective factors in flood are the distance from the river, and the slope; the most effective factors in the destruction are the wasting of groundwater and eliminating the geotechnical properties of the soil; the most effective factors in the occurrence of earthquake are the distance from the major and minor faults which determine the length of major and minor faults. Based on the results of this research and their analyses in Tehran’s districts, areas with very high, high, moderate, low and very low susceptibility were observed. Then, considering this study, their percentages were calculated in each class and reported in the form of a table. Among the 22 districts of Tehran city, districts 1, 3, 18, 5, and 4 are more susceptible than the rest of districts and districts 9, 10, 11, 12, and 17 are less susceptible in terms of the four aforementioned hazards.
Therefore, it is recommended that the process of reinforcement and standardization of existing facilities and infrastructure to be implemented by prioritizing hazardous zones. Concerning the construction and development of new infrastructure and facilities, the occurrence and exacerbation of these natural hazards within the hazardous areas may be prevented by imposing restriction or not issuing construction permits.
Hossein Nazmfar; Saiedeh Alavi
Abstract
Extended Abstract
Introduction
The rapidity of urbanization, especially in developing countries, has led to the fact that half of the world’s population is currently settled in urban areas. Most of these areas with high population density are vulnerable to crises (Shelter Center, 2010: xiv). ...
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Extended Abstract
Introduction
The rapidity of urbanization, especially in developing countries, has led to the fact that half of the world’s population is currently settled in urban areas. Most of these areas with high population density are vulnerable to crises (Shelter Center, 2010: xiv). The fact is that the increase in the concentration of physical capital, infrastructure and economic activities in the cities has led to the increase in adverse effects of natural disasters (Tangri et al., 2008: 30; Lall and Deichmann, 2012). Meanwhile, it has long been argued that the earthquake, as one of the most catastrophic and devastating types of natural hazards, especially in developing countries (Dong & Shan, 2013: 85)has caused lots of damages to the properties and assets in urban areas and around them, through the destruction of urban buildings and infrastructure, (Min et al, 2010). Like other developing countries, Iran has experienced a high level of urbanization that has completely changed the physical structure of urban areas (Soltani et al., 2011: 6644), so that by 2015, the urban population of the country has been 74.3 percent, which is estimated to reach 91.5 in 2050 (Statistical Yearbook for Asia and the Pacific, 2015). Increasing urbanization in the cities of the country along with unplanned development is one of the factors that boost the possibility of increasing casualties and damagesdue to the occurrence of natural disasters in the cities of the country (Pourmusavi, 1391: 40) and leads to the loss of resources and achievements whose reestablishment will take many years (Patterson et al, 2010: 128).
Materials&Methods
The present research is of applied type with descriptive-analytical method. Thestatistical population is the buildings of district 9 of Tehran municipality. Tocomplete the library informationin order to understand the status quo, the studies and deductions of the Information Technology and Communication Organization of Tehran Municipality updated in 2015 were used. The indices used in the research have been weighted based on the experts’ opinions using the Analytic Network Process (ANP), and the obtained results have been applied on the layers under study in the GIS environment and the map of each layer has been prepared in the Geographic Information System.Finally, the general vulnerability map of the region was extracted through the integration of the layers under study (overlay). The opinions of the experts are determinant in evaluating thevulnerability of the city, butin this research, in order to reach a precise evaluation, along with the preparation of the map based on the experts’ opinions, the vulnerability scenario has been developed at different intensities, thereby to standardize the data, and to analyze the layers and criteria, the fuzzy model andthe linear threshold function have been used, respectively. The results have been categorized into 5 vulnerability groups of very low, low, medium, high and very high, and the percentage of each group has been calculated. Tools used in the research are SUPER DECISION and GIS.
Results&Discussion
The present research was carried out aiming at vulnerability evaluation of urban buildings in district 9 of Tehran municipality to various intensities of earthquake, thus, in this research, the vulnerability rate of urban buildings to various earthquake intensities was measured using ten indices (type of material, type of view, building density, age of the building, number of floors, ground area of buildings, compatibility of neighboring uses, distance from fault, geological formations and the width of passages)along with the required sub criteria. To design the earthquake scenarios at different intensities, the first step was to accomplish stratification for each of the main criteria and sub criteria using the weights obtained from the ANP in the Arc GIS environment, then, the general vulnerability map of the region was prepared by overlaying the layers. Finally, the earthquake scenarios at different intensities were designed by fuzzification of the map.
Conclusion
In order to determine the seismicity potential of the study area which is part of the primary and very important stepsin the process of the determination of vulnerability levels of various regions to earthquake, the preparation of the major faults’ map of the region, the preparation of the earthquakes epicenter map, the determination of the intensity and magnitude of earthquakes, the estimation of the features of earthquakes that are likely to occur by the significant faults of the study area were placed on the agenda. For this purpose, in order to evaluate the vulnerability of earthquake hazard, 10 indices were investigated as the effective factors on the vulnerability of urban buildings which have been selected based on the indices of previous studies. These indices (type of material, type of view, building density, age of the building, number of floors, ground area of buildings, compatibility of neighboring uses, distance from fault, geological formations and the width of passages) were analyzed using the ANP calculation method whichhad beenscored by the experts, and the weight of criteriawas applied to the effective layers of the vulnerability, and finally, the general vulnerability map was extracted by integrating the layers in the GIS environment. In order to evaluate the vulnerability rate of urban buildings, the data obtained from the ANP model was fuzzified, and the earthquake scenarios were ultimately designed based on the seismicity potential of Tehran faults and were applied on the general vulnerability map of the study area. The results of the research indicate that in an earthquake with a modified intensity of 6 mercalli, the vulnerability rate of urban buildings in the vulnerability ranges of very low, low, medium, high and very high are 26%, 56%, 17%, 1% and 0%, respectively and the damaged buildings in the districts 1 and 2 are in the vulnerability ranges of very low (28% & 24%), low (53% & 59%), medium (18% & 16%), high (1% & 1%) and very high (0%). In an earthquake with a modified intensity of 7mercalli, the vulnerability rate of urban buildings in the vulnerability ranges of very low, low, medium, high and very high are 21%, 10%, 52%, 16% and 1%, respectively, and the damaged buildings in the districts 1 and 2 are in the vulnerability ranges of very low (23% & 18%), low (11% & 9%), medium (48% & 56%), high (17% & 16%) and very high (1% & 1%). In an earthquake with modified intensity of 8mercalli, the vulnerability rate of urban buildings in the vulnerability ranges of very low, low, medium, high and very high are 7%, 4%, 10%, 61% and 18%, respectively.
Faeze Eslamizade; Heidar Rastiveis
Abstract
Extended abstract Introduction Given the population growth and increasing urbanization, the occurrence of natural disasters like earthquake can cause heavy losses and damages and interrupt the development of cities and countries. Among these disasters, the earthquakeisof great importance due to its unpredictability ...
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Extended abstract Introduction Given the population growth and increasing urbanization, the occurrence of natural disasters like earthquake can cause heavy losses and damages and interrupt the development of cities and countries. Among these disasters, the earthquakeisof great importance due to its unpredictability and high frequency in relation to other events, as well as its location on the earthquake belt. According to the last year's estimate, Iran has been one of the 6 countries with high mortality rates in earthquakes. Therefore, finding a way to minimize the losses can be critical. Crisis managers need quick information from the affected area after the earthquake to minimize the fatalities and financiallosses. The destruction map is one of the information that helps crisis managers. These maps show the destructed buildings or roads with their degree of destruction. With these maps, the destructed buildings and roads can be found quickly. Materials & Methods Many methods are used to prepare the destruction maps, such as aerial/satellite images, LiDAR data, etc. These information can be used to determine the destructed buildings automatically or by visual interpretation. Visual interpretation for determining the degree of destruction requires operator. Although this method has high accuracy, it is less considered because it is time consuming and needs specialists to interpret the data. Therefore, researchers have focused on automated processing techniques for the production of the destruction maps. Various automatic change detection techniques are used to evaluate the destruction resulting from earthquakeby comparing satellite images in two pre and post-earthquake periods based on satellite and aerial images. LiDARdata is one of the most important sources of information to determine destructed buildings with high accuracy and speed. LiDAR data provides the possibility of 3-D demonstration of the destructed region. This information is a great help in preparing the destruction map automatically. The recent expansion of the LIDAR technology is due to the high spatial power of these data. As a result, many researchers have focused on developing an automatic destruction map using Lidardata.Although considering the textural information from the Lidar data, like homogeneity in the destructed region can be effective in distinguishing between the destroyedand undestroyed buildings. In this paper, a new algorithm is proposed to prepare the destruction map after the earthquake by integratingthe post-event high resolution satellite images and post-event LiDAR data. In the proposed method, different textural descriptors of the LiDAR image and data are extractedafter the necessary preprocessing on the satellite image andLiDAR data after the earthquake. In the next step, using the layer of buildings extracted from the map,the areas of the buildings are extracted from the satellite image and LiDAR data, as well as the satellite image descriptors and LiDARdata.Then, the textural descriptorsextracted from the satellite image and LiDAR data are combinedtogether. After that, the points inside this area are categorized into two classes of "debris" and "intact" by the method of support vector machine. Finally, based on the area of the debris class of each building, destroyed and undestroyed buildings were identified by taking a threshold limit into consideration. This algorithm is executed on each building from the destruction part to produce the final destruction map Results&Discussion In order to evaluate the proposed method,the data set was selected from the city of Port-au-Prince, the capital of Haiti, after the 2010 earthquake. According to the USGS reports, 97,294 buildings were damaged and 188,383 were destroyed in Port-au-Prince and most of the southern parts of Haiti. Furthermore, reports show that 222,570 people were killed, 300,000 were injured, and 1.3 million people were displaced. The sample data set include post-event WorldView II satellite images as well as post-event LiDAR data. The WorldView II satellite took images on January, 16 2010, and the LiDAR date was also obtained from this topography website. Obtaining LiDAR data is from January, 21 2010 to January, 27 2010. The vector map of the selected test area was generated in ArcGIS environment. By evaluating the proposed method and using the existing data, the overall accuracy of 97% and the Kappa coefficient of 92% were obtained which proved the reliability of this technique. Conclusion In this paper, a new method for the generation of damage map based on the integration of high resolution satellite images and LiDAR data was proposed. The results show the ability of this method in generating destruction maps based on the satellite images with high resolution and LiDAR data. In comparing similar studies, the results are satisfactory. The selection of the appropriate descriptors, correct training data, the elimination of non-building areas from the sample data, the integration of satellite images and LiDARdate can be known as the reason behind obtaining these results.
Habib Sahami; Sodabeh Papi; Nahid Khosravi
Abstract
Extended abstract
Introduction
Urban old fabrics are supposed to be one of the most vulnerable parts, which are affected in natural disasters mostly earthquakes. The buildings in such areas have no sufficient resistance because of long age and life span and in case of earthquake they are collapsed ...
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Extended abstract
Introduction
Urban old fabrics are supposed to be one of the most vulnerable parts, which are affected in natural disasters mostly earthquakes. The buildings in such areas have no sufficient resistance because of long age and life span and in case of earthquake they are collapsed and may follow the losses of life and property. The main purpose of this article is to analyze and investigate the vulnerability of old fabrics in the downtown Boroujerd city to countermeasure the earthquake and to manage the crisis after the occurrence. The nature of this research is theoretical and practical and the research method is descriptive-analytial. The required data have been collected from library and through field work. In this study, AHP method is used to analyze the area under investigation. The extracted indices are analyzed with the help of GIS and Arcmap. The results indicate high and intensive vulnerability of buildings, if an earthquake occurs. The majority of buildings are suffering from low quality materials, high population density and the establishment of organic tissue and narrow alleys, which results in the rise of destruction and therefore, causes heavy losses of life and property. The readiness to counter the crisis can mitigate the earthquake effects and by knowing the special dimensions of vulnerable buildings , population and also road networks , can speed up the process, and by using time, reduce the casualties which is possible only when parameters are available for making geospatial data basis
Materials & Methods
The research method was applied in terms of the aim, and descriptive-exploratory in terms of conduct. The pivotal principles of this investigation is based on vulnerable points in order to countermeasure the earthquake hazards. The collection of data is accomplished through library noting and field survey. In this study, the evaluation criteria and their weights were determined with acceptable accuracy by reviewing the literature, experts and paired in the form of AHP. The AHP method is used in this study to determine the vulnerability of old fabrics of the central Boroujerd city. This consists of six parameters and indices which include population density, passages width, building material ages, quality and the number and finally the number of floors. Weighing such parameters is carried out with the help of Expert Choice 2000 software and the weights are logged in the GIS software and in an Arcmap environment. The required analyses are observed on them. The area of this investigation is the old fabrics in downtown Boroojerd. The focus on this area is mainly due to old ages and the presence of significant historical places. The vulnerability factors are numerous, which are either natural, physical, social, economical, fundamental, rules and regulations , etc., but the most important boosting factors of the cities risk probabilities and their vulnerability enhancement can be summarized as Placement and locating of the city on various faults, Population concentration , failure to comply with retrofit rules and regulations, the lack of people’s knowledge of local citizen in facing emergency conditions and unexpected crises.
Results & Discussion
The results of the research show that in order to find the most suitable pattern of intervention to countermeasure the vulnerability of old fabrics in the city downtown is to reduce the time laps after every local crisis like an earthquake, to reduce the effective factors by creating a spatial data basis for vulnerable buildings, congested population in buildings and a proper knowledge about the communication networks in the old fabrics to minimize the Consequences. Weighing of these parameter, are carried out with the help of Expert Choice 2000 software and the weights are logged in the GIS software and in an Arcmapenvironment. The required analyses are plotted and observed on them.
Conclusion
It is concluded that, in the southern, western and central parts of old fabrics in Boroojerd city, the relief operations and crisis management efforts should be extended and the precautionary measures and preparedness must be augmented. Several suggestions have been proposed in order to minimize the casualties and damages in case of any probable threats and crisis, which include the renovation and reconstruction of structures with high ages and the improvement along with strengthening the old fabrics and their reinforcement. It has also been concluded that the majority of buildings are suffering from low quality materials, high population density and the establishment of organic tissues and narrow alleys, which results in the rise of destruction and therefore, causes heavy losses of life and property.
Heydare Lotfi; Hosseyn Musazadeh
Abstract
Extended Abstract Introduction In order to analyze the reduction of the impacts of natural hazards, particularly the earthquakes, four basic constituents such as conceptual understanding of development, vulnerability, recognition of the concept of risk, conceptual understanding of capacity building, ...
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Extended Abstract Introduction In order to analyze the reduction of the impacts of natural hazards, particularly the earthquakes, four basic constituents such as conceptual understanding of development, vulnerability, recognition of the concept of risk, conceptual understanding of capacity building, and also, the recognition of risk management approaches are essential. Earthquakes and mass movements are a function of environmental factors, and identifying and segregation of seismic areas and hazard zonation is an important step in assessing environmental hazards. Therefore, Geographic Information Systems (GIS) and multi-criteria decision-making systems are the appropriate tools for zoning land in relation to seismic hazard. In this regard, the study of earthquakes and the areas with high seismic potential for all-round planning and management is imperative and inevitable. Therefore, the present research aims to study the vulnerable areas against natural hazards in Iran. Materials & Methods The present research is descriptive-analytical with regard to the nature of the problem and the study subject, and is a type of applied studies with an emphasis on quantitative methods. The purpose of the study is to investigate the vulnerable areas against natural hazards with an emphasis on earthquakes (Case study: Iran). In this research, the Modis Image (MOD11A1 product) of Terra satellite was used for the years 2000 to 2018. These images have a resolution of one kilometer. Therefore, each pixel of these images covers an area of about 100 hectares of land. To identify the sites with high seismic potential, criteria such as: altitude, earth temperature, the numbers of seismic events between the years of 2000 and 2018 were taken into consideration. In order to calculate the density and intensity of the earthquakes occurring, the data from the United States geological site (related to Iran) was used, and the final output was calculated by the interpolation methods of geo-statistical IDW model - a technique which predicts unknown points based on the correlation between the measured points and their spatial structure - and the arithmetic overlapping in the GIS environment. All processes and data analysis were used in the GIS environment and eventually the overlay of the final output was determined in the form of a map (vulnerability). Results & Discussion In order to measure the impact of effective factors on earthquakes, the analytical software mentioned in the research methodology section was used and also, to determine the indexes effective in determining low and high risk areas for identifying the seismicity and land evaluation for different types of activities and the amount of importance of each of these criteria relative to each other with regard to the present state and the collected information and the investigation and study of the books, previous plans and experts’ opinions have been implemented, which has ultimately entered into the GIS in the forms of information layers. In the next stage, the information layers are given weight proportional to the degree of importance and its effect on the selection of the appropriate field. In order to achieve these indices, a series of maps and databases were needed so these were prepared in the GIS environment. In this research, it is assumed that by analyzing long-term time series of satellite data, such modifications can be monitored. Therefore, in this research, the profile of temperature changes was analyzed using the MOD11A1 product of the Modis sensor during the years 2000 and 2018 in Iran. the results of the research show that the temperature variation pattern for each class is different, and in general, show the increase, stability, and then logical increment over the 18-year period, which can help researchers to identify temperature changes and consequently, to select the appropriate time period to take an image to investigate the changes in the coverage of the study area. Conclusion The study area, with regard to the mainly low topography, tectonic activity and high seismicity, diverse geological and climatic conditions, have the major natural conditions for the creation of a wide range of earthquakes, and these earthquakes bring a lot of financial losses to the region annually but unfortunately, all periodic studies have been carried out without accurate and efficient planning by the relevant authorities to date. Therefore, studying and zoning of susceptible seismic areas is necessary from an absolutely scientific view. Given the obtained finalized map and the study of temperature changes and occurring events, it can be concluded that parts of the south and southwest (Bushehr, Kermanshah, Hormozgan, Khuzestan, Ilam) are very vulnerable and exposed to severe damages. Also, the latitudes related to the central half and the southeast of the country (Kerman, Sistan and Baluchestan, southwest of southern Khorasan, east of Yazd) are exposed to moderate to high damages, and the northern part of the country (Golestan, Mazandaran, Gilan, Ardebil) are located in low damage zone because with regard to the thermal investigations within the framework of the seismic identification, they are located in the high to low thermal zones. Therefore. We find out that more than one third of Iran is faced with high, one third with moderate and one third with relatively low risk. One of the main causes of the earthquake is the high heat inside the Earth where is very hot and reaches to five to six thousand degrees Celsius. Wherever there is heat, there is movement as well, so the heat of the Earth’s center moves to the top layers and displace them.
Mohsen Saghaei
Abstract
Extended Abstract Introduction The worn out textures are one of a variety of urban textures that are spatially unstable due to physical deterioration and inappropriate enjoyment and the existence of vulnerable infrastructures and are one of the main challenges facing most cities and especially metropolises. ...
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Extended Abstract Introduction The worn out textures are one of a variety of urban textures that are spatially unstable due to physical deterioration and inappropriate enjoyment and the existence of vulnerable infrastructures and are one of the main challenges facing most cities and especially metropolises. Currently, 53 spots of worn-out texture spots have been identified in 15 regions of Esfahan which now have 350,000 inhabitants living in these areas. Meanwhile, the extent of the worn out texture in the Isfahan’s region 5 is 69.75 hectares. This article seeks the extent to which the identification and prioritization of worn out textures within the scope of the study area can affect the revival and reduction of their vulnerability. Methodology Regarding the purpose of the research, this research is an applied type and the method of studying and analyzing information and data is a descriptive-survey method. According to the country's standards, the criteria of the gravels fineness, impermeability, and instability have been taken into considerations, and analyses were carried out using the AHP model and the GIS software. Discussion The main objective of this research is to prioritize worn out textures for restoration and renovation, the first step of which is to identify such textures. The criteria and indices which have been considered in this research include: material genus, the degree of deterioration, the age and the extent of the real estate, and to analyze the desirability and prioritization of worn out texture in order to modify the texture erosion, the indexes should be scored after defining the criteria and indexes and performing the initial classification. In the next step, scoring of the internal values of each of the indices was done and in the final stage, the coefficient of importance of each criterion was determined using the AHP model and the Thomas hourly table and the criteria with the same weight were combined and the final output was obtained. Conclusion The results indicate that the lack of facilities, utilities and infrastructure has led to the migration of local residents to other areas and negatively impacted the population growth rate in recent years. On the other hand, due to the socioeconomic condition of the inhabitants of the texture, the process of reconstruction and renovation inside the texture has slowed down and this factor has exacerbated the deterioration of the texture.
Amir Mahmoudzadeh; Iran Ghaazi; Maryam Askari
Abstract
Abstract[1]
As the most devastating natural disaster,the earthquake is considered to be the cause of human casualties and significant economic losses in the country, which is far more severe in urban worn out textures, because the worn texture has a distinct and unique structure. The area of the worn ...
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Abstract[1]
As the most devastating natural disaster,the earthquake is considered to be the cause of human casualties and significant economic losses in the country, which is far more severe in urban worn out textures, because the worn texture has a distinct and unique structure. The area of the worn out texture of Ilam city is 374 hectares, which covers 19% of the total area, including the old parts and the central texture of the city. The research method in this study is descriptive-analytical and field research. The purpose of this study was to evaluate the management of earthquake crisis in Ilam's worn-out texture in which, indices such as type of materials, age of buildings, number of floors, type of uses, occupation level, quality of buildings, population density, width of passageways, and area have been studied. The results show that the building materials account for the highest weight and the other factors are a function of the condition of the materials used in the structure. The output vulnerability map showed that out of the total area except the passageways, 8.9% had very high vulnerability, 59% had high vulnerability, 23% had moderate vulnerability, 3.6% had low vulnerability, 5.5% had very low vulnerability and overall, 67.9% of the worn-out texture area is vulnerable based on existing indicators.The research proposals have been presented in three areas: high vulnerability, moderate vulnerability and low vulnerability.
[1] - به دلیل کیفیت نامناسب متن چکیده مبسوط انگلیسیِ ارائه شده توسط نویسنده مسئول مقاله، نشریه به ناچار اقدام به ترجمه مجدد متن چکیده فارسی و انتشار آن به جای چکیده مبسوط انگلیسی نموده است.
shahabadin isalou; Gholamreza Latifi; VAHID GOODARZY
Abstract
Abstract
Confronting natural disasters and managing that by using the most efficient means, have always been subjected to deliberation, investigation and examination from various aspects. But, a comprehensive and locative analysis on the spur of the moment is always an essential act that must be taken.In ...
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Abstract
Confronting natural disasters and managing that by using the most efficient means, have always been subjected to deliberation, investigation and examination from various aspects. But, a comprehensive and locative analysis on the spur of the moment is always an essential act that must be taken.In this field, geographic information system is capable through integrating information of providing a comprehensive analysis and identification of the zones which require attention and have been very effective. Among natural disasters, earthquake is very unpleasant and leaves the highest mortality rates, hence, its management is very important, especially in the urban context. Most injuries from the earthquake due to the physical resistance of tissue, the impossibility of relief and incapability of reversibility had been in direct or indirect connection with undesired structural situations. This paper tries to offer the most effective strategies to achieve a higher quality of physical safety against potential earthquakes through assessment of physical vulnerability and determine vulnerable zones.
Materials & Methods:
Using the five indicators, (population density, land use risks, quality of buildings, age of buildings, access to the centers of relief and rescue) information layers of each of these variables were produced and these layers were integrated using the Analytic Hierarchy Process IHWP in Arc GIS environment, and the location of district 1 was evaluated against earthquakes.
Results & Discussion:
Findings show that the physical texture of district 1 in Tehran is relatively safe against possible earthquakes, districts 9, 7 and 5 are very safe,districts 4, 6 and 10 are safe, and districts 2 and 8 are moderately safe. Districts 1 and 3 were assessed as areas with low safetyand subjected to disaster. In general, the north of this area has narrow passageways and streets, high-rise buildings, worn out textureand ruined sites, which is unsafe and vulnerable to earthquakes.
Conclusion:
Based on the principles of urban management,non-standard sales of building density by the municipality of Tehran in this area and the growing trend of population is considered to be the main problem and a serious threatening alarm to the life of the region.
Seyed Ali Alavi; Seyed Mostafa Hosseini; Fariba Bahrami; Mehrab Ashorlo
Abstract
Planning with the aim of crisis management and earthquake risk estimation has always been one of the main concerns of urban planners and managers. In order to plan crisis management before the occurrence of earthquake, determining the vulnerability rate of urban fabrics to earthquake is necessary. ...
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Planning with the aim of crisis management and earthquake risk estimation has always been one of the main concerns of urban planners and managers. In order to plan crisis management before the occurrence of earthquake, determining the vulnerability rate of urban fabrics to earthquake is necessary. This research was aimedat providing an appropriate model for assessing the vulnerability of urban fabrics of Semirom city,located in Isfahan province, to earthquake. The current research is descriptive-analytical in nature with practical aims. To begin with, the criteria affectingthe vulnerability of urban fabrics to earthquake were identified, and then the value and importance of each criterion was determined by using Analytic Network Process. Finally, the results obtained from Analytic Network Process, were integrated with main and side roads, population density, buildingsquality, land slope, distance from fault, green space, health centers, cultural centers, and educational and residential centers, and vulnerability map of Semirom’s urban fabrics to earthquake was prepared. The results showed that among the studied criteria, population density, side road and distance from the fault were the most important criteria, while distance from cultural and educational centers had the least importance in vulnerability of urban fabrics. Furthermore, vulnerability of the northern and central parts of the city was higher than other areas of the city due to their proximity to the fault line and the presence of old buildings in these parts. Based on the results obtained from digital layer of urban fabrics of Semirom city, losses and damages caused by the earthquake can be significantly reduced by proper planning before and after the occurrence of earthquake. It should also be noted that tectonic aspect is one of the factors that has always been neglected throughout the history; therefore paying attention to slope issue and other factors in urbanism has had evolutionary process.
Mohammad Eskandari; Mahdi Modiri; Babak Omidvar; Aliasghar Alesheikh; Mohammadali Nekooie; Ali Alidoosti
Abstract
Abstract The earthquake phenomenon is a natural disaster that causes many fatal, financial and environmental damages every year. Iran is extremely vulnerable to earthquakes due to its seismicity and its location on the earthquake belt. Also, a large number of facilities were built before the formulation ...
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Abstract The earthquake phenomenon is a natural disaster that causes many fatal, financial and environmental damages every year. Iran is extremely vulnerable to earthquakes due to its seismicity and its location on the earthquake belt. Also, a large number of facilities were built before the formulation of earthquake resistant standards and, unfortunately, the quality of construction in some cases in the country is not optimal. Therefore, considering the suspicious behavior of the networks regarding the occurrence of possible earthquakes, the issues of assessing the seismic vulnerability of critical infrastructure are of particular importance. In this paper, a model has been presented in which, first, the risk analysis of the area of interest (based on the two existing attenuation relations for the country) is carried out, which, given the uncertainties involving in the earthquake occurrence (including magnitude of earthquake, focal depth and position of the earthquake epicenter), this operation is randomly selected at each time of the analysis, and after each hazard analysis, the outputs resulting from the earthquake hazard including the maximum acceleration values, the maximum speed and the displacement of the ground are calculated. If the area has a landslide or liquefaction potential, then the outputs resulted from the earth fault risk, including the values of liquefaction and landslide displacements, should be introduced into the model for each feature. Then, seismic vulnerability functions are used which are placed on the model database for both ground shaking hazard and ground failure for the arteries. At the end, based on the existing vulnerability functions, the network damage analysis is dealt with. All these steps are for a single analysis. Therefore, based on the Monte Carlo simulation, all of these operations are repeated 10,000 times to include all uncertainties and failure states, and the outputs in the database are averaged to account for all failure states. For this purpose, due to the large volume of descriptive and spatial data, on the other hand, large spatial analysis of data and the high volume of mathematical equations for repetition of operations, coding in the Visual Studio environment with the C # programming language was done, using the Net Framework and Arc Engine libraries which led to the production of a software system using a database and with spatial analysis and deduction capabilities based on spatial information systems (GIS) that could assess the possible slight, moderate, extensive and complete failure rates of each artery separately in the form of maps and tables for each feature. In this paper, to better illustrate this research, the existing model for the city of Neyshabur was implemented and analyzed.
Monireh Shamshiri; Mahdi Akhondzadeh Hanzaei
Abstract
Discussion about earthquake to reduce its casualties and damages is very important, especially in a seismic area like Iran where the occurrence of this natural phenomenon is seen annually. Anomaly detection prior to earthquake plays an important role in earthquake prediction. Ionosphere changes which ...
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Discussion about earthquake to reduce its casualties and damages is very important, especially in a seismic area like Iran where the occurrence of this natural phenomenon is seen annually. Anomaly detection prior to earthquake plays an important role in earthquake prediction. Ionosphere changes which are recognizable by remote measurements (such as using Global Positioning System) are known as earthquake ionospheric precursors. In this study, two data sets from the ionospheric Total Electron Content (TEC) derived from the GPS data processing by Bernese software were used for two studies, Ahar earthquake, East Azerbaijan (2012/08/11) and Kaki earthquake,Bushehr (2013/4/9), and the results were compared with data obtained from the global stations. Because of the nonlinear behavior of TEC changes, in order to predict and detect its changes, integration of neural network (using multilayer Perceptron (MLP)) with particle swarm optimization algorithm (PSO) was used. Particle Swarm Optimization algorithm with a performance based on the population can be effective in improving estimatedweight by artificial neural network. By analyzing the causes of ionospheric anomalies including the geomagnetic fields and solar activities and their removal from the processes, the results indicate that some of this anomalies caused by the earthquake and using intelligent algorithms were able to have appropriate efficiency for the prediction of nonlinear time series. The output resulted from the integration of artificial neural network and PSO shows that both positive and negative anomalies occur. The anomalies before earthquakes often occur close to the epicenter of the earthquake and are visible 3 days before the Ahar earthquake and 2 to 6 days before the Kaki earthquake are.
Mahdi Modiri
Volume 17, Issue 67 , October 2008, , Pages 2-12
Abstract
In order to evaluate the potential for earthquake surface fracture, a new application of highly accurate geological mapping with total electronic station is presented. This method makes it possible to detect secondary faults, which represent 30-cm-long vertical displacement that does not appear on the ...
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In order to evaluate the potential for earthquake surface fracture, a new application of highly accurate geological mapping with total electronic station is presented. This method makes it possible to detect secondary faults, which represent 30-cm-long vertical displacement that does not appear on the surface. These very small faults do not have signs and symptoms of topology, so it is likely that they will not be considered though they show the existence of faults in the range of installations and movements. This method involves mapping of points in geological features and accurate and comprehensive analysis of computer details and field operations of abnormalities at the heights of mapped points. General abnormalities are considered at high altitudes that are mainly consisting of normal and inverted fault. However, this method can be used for longitudinal slip faults as well. This method provides the conditions where geological data can easily be integrated into GIS and 3D analysis of details of small structure features can be achieved; field data can be analyzed in the profiles of three dimensional diagrams and in maps that are made using cartographic software. The ability of this method to identify faults with slight displacement allows the types of metamorphism, reduction in displacement of the direction of small and divergent faults, located at the two extremities of large and ordinary faults, single-slope bends and transverse structures between faults can be determined.
Hossein Klantari Khalil Abad; Hossein Hataminejad; Aref Agha Safari
Volume 16, Issue 61 , May 2007, , Pages 54-60
Abstract
Most of the buildings in the historical texture of Yazd have not been adequately resistant to earthquakes, and the rules, regulations and criteria have not been observed in their design. Most of these buildings are old and some of them are newly-built. The occurrence of earthquake entails serious and ...
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Most of the buildings in the historical texture of Yazd have not been adequately resistant to earthquakes, and the rules, regulations and criteria have not been observed in their design. Most of these buildings are old and some of them are newly-built. The occurrence of earthquake entails serious and irreparable damages to buildings, facilities, equipment, natural resources, social order, historical and cultural heritage, activities, employment and income, organizations and executive agencies, transportation system and business, therapeutic, health, educational, religious, etc. functions, and will lead to crisis. The crisis management process requires implementation of measures before, at the beginning, during and after the crisis.
Gholam Reza Latifi
Volume 15, Issue 59 , November 2006, , Pages 22-26
Abstract
The expansion of cities and urbanization and the gradual increase of the number of large cities in the world especially in developing countries including Iran on the one hand, and the growth of cities, concentration and accumulation of population, and increase of environmental and economic load on them ...
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The expansion of cities and urbanization and the gradual increase of the number of large cities in the world especially in developing countries including Iran on the one hand, and the growth of cities, concentration and accumulation of population, and increase of environmental and economic load on them on the other, have led, in addition to greater attention paid to cities, to the acceptance of numerous roles and functions by them. One of the issues that most of the big cities in the world are concerned with is natural disasters. The unpredictability inherent in most of natural disasters and the need for rapid and correct decision-making and implementation of the operation in their face have created the theoretical and fundamental foundations of a science named Crisis Management. This science refers to a set of activities that take place before, during and after the crisis to reduce the effects of these incidents and decrease vulnerability. This has a special relationship with geography and urban planning and management. By using the principles and regulations of urban planning and by clarifying the concepts of this science such as the form, texture and structure of cities, urban land use, communication networks, urban infrastructure, etc., we can greatly reduce the effects and consequences of natural disasters. The geographic extent of Iran is one of the most vulnerable parts of the Planet in terms of the probability of occurrence of these events, especially earthquakes. Every year the occurrence of these incidents causes a great deal of life and financial losses, and urban areas have always had a bitter experience of the occurrence of such disasters. It seems therefore to be necessary to carry out specific planning for the safety of urban spaces. Cities are severely damaged by such cases due to population concentration and economic investment in them. Since the beginning of their formation, they have chosen a particular form and structure for their growth and have expanded over time. The science of urbanization can reduce the effects of such disasters by explaining its principles and concepts and by relying on geographical data, and crisis management can use these data to implement the necessary management principles to reduce the vulnerability of cities to these events.
Sirous Ghanbari; Arman Ghazi Askari Na'eenei
Volume 14, Issue 56 , February 2005, , Pages 54-60
Abstract
In order to prevent, counteract and reduce the effects of natural disasters such as earthquakes, we have to deal, in addition to technical matters, with crisis management and planning how to deal with crises caused by natural disasters. If the probable problems arising from the crisis are not foreseen, ...
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In order to prevent, counteract and reduce the effects of natural disasters such as earthquakes, we have to deal, in addition to technical matters, with crisis management and planning how to deal with crises caused by natural disasters. If the probable problems arising from the crisis are not foreseen, the cost of reconstruction and repair of damages by the crisis will be very high. Crises caused by natural disasters will have significant socio-mental and economic effects on society. Therefore, recognizing the principles of proper methods of disaster management can be effective in preventing the occurrence or reduction of the negative effects of these incidents and preventing them from becoming social, economic and environmental crises. Therefore, the availability of proper management plans in times of crisis will, on the one hand, strengthen the foundations of society in all fields and, on the other, significantly decrease the amount of financial and life damages and prevent social, economic and environmental collapse.
