11 research outputs found

    Conceptual change of disaster management models: A thematic analysis

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    Different models have been proposed for disaster management by researchers and agencies. Despite their efficiency in some locations, disasters are still a fundamental challenge in the way of sustainable development. The purpose of this research is developing a comprehensive conceptual model for disaster management using thematic analysis. In this regard, first, disaster management models are collected. In the next stage, the themes of each model are extracted and categorised in three phases. In the first phase that is descriptive coding, available elements in each model are extracted as code and the basic themes are recognised. Then, in the phase of interpretive coding, basic themes are classified in three categories that are called organising themes (i.e. hazard assessment, risk management and management actions). In the final phase, strategic management is selected as the global or overarching theme to integrate all the other themes. Based on thematic analysis, it can be concluded that disaster management has three main elements that are the three organising themes. Therefore, comprehensive model of disaster management should include these three elements and their sub-basic themes that is called the ideal or criterion type. Results showed that some scientists have looked at disaster management one dimensionally (one theme). Even in two-dimensional models, one dimension has advantage over the other one. While the proposed typology in this study showed that the comprehensive model should include all the three mentioned elements

    Provide a model for the seismic damage Assessment to buried fuel pipelines in Kermanshah

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    Fuel pipeline systems are one of the most important lifelines in city and have a key role in increase and decrease of damages and vulnerability to earthquake. Kermanshah has three lines for transferring oil products and crude oil into the main refinery of the city from two transfer centers out of the city, Naftshahr and Tange Fanni, from which oil products are transferred to the terminal facilities in Sanandaj. This paper, In order to assess the seismic damage to buried fuel pipelines of Kermanshah with the help of characteristics and information of network components, PGA and PGV values are initially determined for two probable scenario earthquakes in the study area, using the attenuation relations of the same area. Then, using the repair rate relations, damage to pipelines is estimated. The probability distribution function for the area, the population and the number of houses exposed to fire and explosion after the earthquake are calculated using the Monte Carlo simulation method through numerous repetitions All the steps of damage assessment for buried pipelines were written in a GIS environment. In order to give a better description of the output results, the probability distribution functions for each output are provided. In summary, the damage inflicted on the fuel pipelines of Kermanshah is equal to 17 leaks, 4 breaks and 21 ignitions for scenario 1 and 4 leaks, 1 break and 1 ignition for scenario 2. The purpose of this paper, an efficient algorithm present is for seismic damage analyze of buried fuel pipelines and simulating fire ignition and explosion in urban areas. The proposed algorithm for the city of Kermanshah has been used as a case study

    Analysis and modeling of safety parameters in the selection of optimal routes for emergency evacuation after the earthquake (Case study: 13 Aban neighborhood of Tehran)

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    Introduction : Earthquakes are imminent threats to urban areas of Iran, especially Tehran. They can cause extensive destructions and lead to heavy casualties. One of the most important aspects of disaster management after earthquake is the rapid transfer of casualties to emergency shelters. To expedite emergency evacuation process the optimal safe path method should be considered. To examine the safety of road networks and to determine the most optimal route at pre-earthquake phase, a series of parameters should be taken into account.   Methods : In this study, we employed a multi-criteria decision-making approach to determine and evaluate the effective safety parameters for selection of optimal routes in emergency evacuation after an earthquake.   Results: The relationship between the parameters was analyzed and the effect of each parameter was listed. A process model was described and a case study was implemented in the 13th Aban neighborhood ( Tehran’s 20th municipal district) . Then, an optimal path to safe places in an emergency evacuation after an earthquake in the 13th Aban neighborhood was selected.   Conclusion : Analytic hierarchy process (AHP), as the main model, was employed. Each parameter of the model was described. Also, the capabilities of GIS software such as layer coverage were used.     Keywords: Earthquake, emergency evacuation, Analytic Hierarchy Process (AHP), crisis management, optimization, 13th Aban neighborhood of Tehra

    Human health risk of nitrate in groundwater of Tehran–Karaj plain, Iran

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    International audienceAbstract Groundwater pollution by nitrate has is a major concern in the Tehran–Karaj aquifer, Iran, where the wells provide up to 80% of the water supply for a population of more than 18 million—yet detailed human health risks associated with nitrate are unknown due to the lack of accessible data to adequately cover the aquifer in both place and time. Here, using a rich dataset measured annually in more than 75 wells, we mapped the non-carcinogenic risk of nitrate in the aquifer between 2007 and 2018, a window with the most extensive anthropogenic activities in this region. Nitrate concentration varied from ~ 6 to ~ 150 mg/L, around three times greater than the standard level for drinking use, i.e. 50 mg/L. Samples with a non-carcinogenic risk of nitrate, which mainly located in the eastern parts of the study region, threatened children’s health, the most vulnerable age group, in almost all of the years during the study period. Our findings revealed that the number of samples with a positive risk of nitrate for adults decreased in the aquifer from 2007 (17 wells) to 2018 (6 wells). Although we hypothesized that unsustainable agricultural practices, the growing population, and increased industrial activities could have increased the nitrate level in the Tehran-Karaj aquifer, improved sanitation infrastructures helped to prevent the intensification of nitrate pollution in the aquifer during the study period. Our compilation of annually mapped non-carcinogenic risks of nitrate is beneficial for local authorities to understand the high-risk zones in the aquifer and for the formulation of policy actions to protect the human health of people who use groundwater for drinking and other purposes in this densely populated region

    Sensitivity analysis in seismic loss estimation of urban infrastructures

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    Iran, as a seismic country, is situated over the Himalayan-Alpied seismic belt and has faced many destructive earthquakes throughout history. Therefore, it is very important to evaluate the possible damage to the existing infrastructure based on statistical and spatial analysis. In this study, a new model is developed to analyse seismic damages based on seismic hazard assessment and extraction of the vulnerability function for all features of fuel infrastructure. To consider uncertainty analysis in the model, Monte Carlo simulation is used based on 10,000 iterations. The results of hazard analysis indicated that peak ground acceleration is about 0.18 g and there is slight to moderate damages to the desired fuel infrastructure in the study area. Moreover, sensitivity analysis is also performed to determine how median, standard deviation (or beta), grid size, attenuation relationships, liquefaction and landslide susceptibility impact the seismic loss. Last but not least, the effect of input parameters of earthquake scenarios including magnitude, focal depth and focal distance are also analysed in conjunction with regression analysis. The results of the study show that magnitude and focal distance are the most sensitive parameters in which the expected damage to the fuel infrastructure is reduced by about 25% if the epicentre of the earthquake is moved from 10 to 25 km

    Geospatial Analysis of Earthquake Damage Probability of Water Pipelines Due to Multi-Hazard Failure

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    The main purpose of this study is to develop a Geospatial Information System (GIS) model with the ability to assess the seismic damage to pipelines for two well-known hazards, including ground shaking and ground failure simultaneously. The model that is developed and used in this study includes four main parts of database implementation, seismic hazard analysis, vulnerability assessment and seismic damage assessment to determine the pipeline’s damage probability. This model was implemented for main water distribution pipelines of Iran and tested for two different earthquake scenarios. The final damage probability of pipelines was estimated to be about 74% for water distribution pipelines of Mashhad including 40% and 34% for leak and break, respectively. In the next step, the impact of each earthquake input parameter on this model was extracted, and each of the three parameters had a huge impact on changing the results of pipelines’ damage probability. Finally, the dependency of the model in liquefaction susceptibility, landslide susceptibility, vulnerability functions and segment length was checked out and specified that the model is sensitive just to liquefaction susceptibility and vulnerability functions

    Randomized Prospective Comparison of Two Protocols for Head-up Tilt Testing in Patients with Normal Heart and Recurrent Unexplained Syncope

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    Background: This randomized study was aimed to compare the diagnostic value of two head-up tilt testing protocols using sublingual nitroglycerin for provocation in patients with recurrent unexplained syncope and normal heart. Methods: The patients with normal findings in physical examination, electrocardiography and echocardiography were randomly submitted to one of upright tilt test protocols. The only difference between two protocols was that nitroglycerin was administered after a five minute resting phase in supine position during protocol B. We also considered eighty normal persons as the control group. Results: Out of 290 patients that underwent tilt testing, 132 patients were in group A versus 158 patients in group B. Both groups had an identical distribution of clinical characteristics. Tilt test was positive in 79 patients in group A (25 in passive phase, 54 in active phase) versus 96 patients in group B (43 in passive phase, 53 in active phase). There was no significant difference between results in two groups (P value=0.127). Forty cases were tested with protocol A and forty underwent tilt testing with protocol B. Tilt test was positive in 4 cases with protocol A versus 3 cases in protocol B. The positive rates of tilt testing with protocol A was 60% while it was 61% in protocol B. The specificity of testing with protocol A was 90% and it was 92.5% in protocol B. Conclusions: According to our data, adding a period of rest and returning to supine position before nitroglycerin administration had no additional diagnostic yield
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