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Showing 47 results for Hazard
Zahra Taghizade, Ahmad Mazidi,
Volume 6, Issue 3 (9-2019)
Volume 6, Issue 3 (9-2019)
Abstract
Abstract
Urban heat island (UHI) is one of the environmental phenomenon which has made difficult environmental conditions for citizen. This study aims to evaluate the spatial and locational variability of Esfahan urban heat island according to the role of land use. Thus an area about 190.2 square kilometers (km2) in Esfahan, as the microclimate, was studied. In order to analyze the relationship between land use and land cover changes on Esfahan urban heat island, the images of Landsat 7 (TM and ETM +) and Landsat 8 (OLI / TIRS) on 20 July 1989, 17 August 2005, 18 August 2014 have been used. The results show that the urban areas has experienced 31% changes in positive direction; while the agricultural sector and green space havehad a reduction of 25% in their area. The analysis of the intensity of heat island show that heated cores are related topoor and barren lands with about 37/33 and 36/5. Although the most area of thermal classwere related to warm thermal class in 1989 and 2005, the average thermal classes were about 63/8%in 2014. Moreover, the locational variation distribution of Esfahan heat island shows that the locationof the heat island has gradually changed. For example in 2014 it included small parts in the south of the city, military zones and barren lands in the south, some parts in the north west and north east areas and small areas in the east of Esfahan. This means that urban development isn’t the main factor of the surface temperature increase and urban heat development, but rather the type of land use has influenced the decreasing or increasing of air temperature.
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Mr Mohamad Khalaj,
Volume 6, Issue 3 (9-2019)
Volume 6, Issue 3 (9-2019)
Abstract
Abstract
Seismic potential investigation of Tehran as the capital of Iran is an essential issue because their accumulation around a fault may indicate its seismic potential. Stress trajectories for this estimate are useful. In this research, fault slip data is used for paleo stress analysis. Base on that, the study area divided into 6 stable stress regions and the mean stress tensor related to each region determined. Then the mean stress tensor rotated based on Anderson’s theory representing a compressional tectonic regime. The Stress trajectory map drew based on rotated mean stress tensor acting on the regions during geological time. The resulted map showed the arrangement of sigma1 trajectories in the area obeyed the overall tectonic regime in Iran and limited converge through the junction ignoring addition in stress magnitude and seismic hazard in the junction of major faults.
Given the importance of Tehran as the political-economic capital of the country, and its location in Alborz Basin with high faults density. and due to the seismic background of the area, the necessity of seismic risk assessment in this area becomes more evident. In this research, we have attempted to produce and present a map of faults in the Tehran wide area, focusing on faults in the eastern part of Tehran, Mamlouk, Ghasre Firozeh and the margins, with accurate structural elements and drawing of the stress trajectories, convergence of the trajectories, and stress accumulation at convergence sites, assess seismic hazard at this location based on longitudinal stress data (Katsushi Sato, 2011; Yamada and Yamaji, 2002; Yamaji, 2000; Sippel et al., 2009).
Based on field observations and data collected, scratch faults were selected for collecting and analysis of longitudinal paleo stresses as they record all deformation stages. After collecting the fault data, we stabilized them using the Multiple Inverse Method (MIM) and zone boundaries, and by drawing a Mohr's circle (without scale) for each range, seismic potential analysis was performed (Katsushi Sato, 2011; Yamada and Yamaji, 2002; Yamaji, 2000; Sippel et al., 2009).
To separate the stress phases, obtain the reduced stress tensor, obtain different stress and stress parameters, and plot the stress trajectories, the study area had to be divided into smaller ranges. It is not possible to determine the size of the stress components and the principal stresses by longitudinal stress methods and it is not possible to draw a scaled circle. Therefore, it is possible to draw a circle without scales for fault data only. This circle enables the overall analysis of the field shape, the arrangement of the data in the graph, and the comparison of the relative components of the fault data stress. By the Mohr's circle (without scale) method, the principal minimum stress and the maximum stress difference (s1 - s3) are considered as base (0) and unit (1), respectively, and assume the same size with respect to the relation (F = (s2 - s3) / (s1 - s3)) between the calculation of the middle stress field shape and the field shape factor. Studies show that tensile tectonic structures are not dominant structures in the region. For the kinetic analysis of fault data, precise rock mechanics such as the internal friction angle and the Amonton-Columbus criterion cannot be used precisely. But given the arrangement of the fault data, a large degree of comparison can be made between the kinetic features and especially the fault dynamics of each range. Therefore, the main maximum stress must be horizontal. Assuming that all the faults are coherent and based on Anderson's theory of faulting that the main minimum stress is vertical in the compressive stress regime, the position of the principal stress axes of each range is returned to the conditions of the fault formation (vertical minimum stress). In all ranges, the principal minimum stress is near vertical. After rotation of the data and the vertical axis of the minimum stress was set, the trajectory maps were drawn for horizontal stresses (main and maximum stresses).
A study based on longitudinal stress studies and Andersen's theory introduces the main maximum stress trend N017E, which is in good agreement with the general crustal shortening trend of the Central Alborz (Vernant et al., 2004). Therefore, the major faults of the region do not have a significant impact on the disturbance of the stress field within the region and, in fact, the convergence of these faults does not lead to the convergence of stress trajectories. The positioning of the poles of the fault plates on the main stress plates indicates that along with the crustal deformation in this part of Alborz, the regional structures have been rotated and decomposed. In fact, the reason for the polarization of fault plates on the main stress sheets with zero shear stress is that the rotation and positioning of faults coincide with the rotation and deformation of other geological structures and phenomena such as folds and joints. The arrangement of the poles of the fault plates in the Mohr's circle indicates that the faults in zone 3 have less dynamic potential than elsewhere.
Keywords: Stress Trajectory, Multiple Inverse Method, Convergent Faults, Seismic Hazard, Mamlouk, Ghasre Firouzeh.
Masoumeh Gholami, Ezzatollah Ganavati, Ali Ahmadabadi,
Volume 6, Issue 4 (2-2020)
Volume 6, Issue 4 (2-2020)
Abstract
Simulation of floodplain zones in Tehran's metropolitan watershed (case study: Kaan basin)
Ezaatollah Ghanavati, Associate prof. Geographical science faculty, Kharzmi University
Ali Ahmmadabadi. Assistance prof. Geographical science faculty, Kharzmi University
Negar Gholami, MA in Geomorphology, Geographical science faculty, Kharzmi University
Extended abstract
Floodplains and adjacent rivers are always at risk from flood events due to their specific circumstances. Flood prone area identification in the watersheds is one of the basic solutions for destructive flood control and mitigation. Flood mapping is one of the best methods for flood prone area planning and identifying. Considering the importance of flood hazard, it is important to understand the role of uncertainty and incorporate that information in flood hazard maps. The hydrodynamic modeling approach is suitable for accounting various uncertainties, and thus lends itself to creating probabilistic floodplain maps. For this purpose, flow boundary conditions, peak instantaneous discharge with different return periods, cross sections and their distance and roughness coefficients for each cross section were entered to HEC-RAS hydraulic model in Kaan watershed located in the Tehran province, Iran, and this model was then run and flood water surface profile at different return periods were estimated. In the Kaan Basin, most residential and agricultural lands are located in a very small distance from the river bed. The rapid growth of construction, human activities and land use change in the downstream of the basin have caused a change in the hydrological cycle and runoff production. Floodplain mapping using hydrodynamic models is difficult in data scarce regions. Additionally, using hydrodynamic models to map floodplain over large stream network can be computationally challenging. Some of these limitations of floodplain mapping using hydrodynamic modeling can be overcome by developing computationally efficient statistical methods to identify floodplains in large and ungauged watersheds using publicly.
The aim of this study is to determine flood areas within 20 kilometers of the Kaan River by using the HEC-RAS model and Arc GIS software to identify flood lands in different return periods.
The Kaan basin is located in the central Alborz Mountains. This basin is limited to south, north, east and the west respectively to Tehran, Jajrood Basin, Darakeh Basin and Karaj River Basin. The most important River in the area is the Kaan River and originated from high mountains.
Most commonly, the hydrodynamic modeling approach is used to create flood hazard maps corresponding to a rare high flood magnitude of 100-year return period or higher. Although this approach can provide very accurate floodplain maps, it is computationally demanding. As a result, the modeling approach to flood hazard mapping works well for individual streams, but its efficiency drops significantly when used to map floodplains over a large stream network. In this research, floodplain areas in the Kaan basin in return periods of 2 to 20 years are determined using the HEC-RAS model and the HEC-geoRAS extension. For this purpose, digital maps 1: 25000, DEM (10m), discharge values of Sulaghan Station, morphological characteristics of the river bed and cross sections have been used. Digital Elevation Models (DEMs) play a critical role in flood inundation mapping by providing floodplain topography as input to hydrodynamic models, and then enabling the mapping of the floodplain by using the resulting water surface elevations. Finally, the data is entered into the HEC-RAS software and analyzed. After determining the flood ranges in the various return periods at each cross-section, enter the results to the Arc GIS software and the flood zoning maps were obtained.
In this research roughness coefficients (Maning,s coefficients) for each cross section were obtain be the
n= (nb+n1+n2+n3+n4) m (Eq.1)
Geological map and field observations have shown that the main difference between the widths of the valley in the study area is related to the type of rock. The results of the hydrodynamic model show that in the river upstream, the increase in discharge had led to the water level increase and expansion in the floodplain surfaces. But in the middle and low slopes in the downstream of the river, due to the reduced discharge, the river has a larger lateral extension and the flood areas are larger than the upstream of the river. Also, for a longer period of return, the discharge rate and the water level increase and the flood plain was more extensive. The results show that in the downstream of the basin due to instability the bed, existence of wide and eroded chanels, high ability in sedimentation, erosion of the channel bed, and low impact of vegetation, this section They can be restored and regenerated and constantly changing. Due to the location the Tehran-North high way from the Kaan basin, had the construction of roads and structures, the flood plain areas of the river should be fully observed or retrofitted.
Key words: Environmental hazards, Flood, Flood areas, Kaan River, HEC-RAS
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Esmaiel Najafi, Dr Sayyad Irani Heris, Farshad Jafari,
Volume 7, Issue 4 (2-2021)
Volume 7, Issue 4 (2-2021)
Abstract
Abstract
Since the early 1990s, the idea of sustainable urban development has been a fundamental and very important issue for decision makers and thinkers. Because it encompasses the historical concept of development and at the same time has become very important in determining the current international, national and regional policies (Pugh, 2004). In recent years, governance has become a hot topic in public sector management, and this is due to the important role that governance plays in determining public health. Therefore, according to environmental resources, good governance means the way in which decision makers promote sustainable development, which includes the protection of the living environment (Shuakrizadeh and Ashrafi, 2011). Governance is the institutional capacity of public organizations to provide goods demanded by the public and to help the citizens of the country or their representatives efficiently, transparently, fairly, and with accountability to limited resources. This definition of governance represents an international organization and development institution such as the World Bank that seeks to support reforms through good governance programs aimed at strengthening the strategic capacity of donor governments while intending to engage civil society. Strengthen sovereignty. (Krueger,2007).
Environmental hazards and ecological crises are the result of the interaction of environmental, economic, cultural, health and even political variables. The scope of these variables is local-spherical, so that no place in the earth is far from its consequences, with the difference that the scope and depth of the crisis is severe and weak (Kaviani rad, 2010). Investigating the effects of environmental hazards in relation to sustainable development with a good governance approach is very important and very important in terms of nature, so the present study with descriptive-analytical approach and based on library and field studies to study the effects of environmental hazards on sustainable indicators of Mazandaran province It has dealt with the characteristics of decent humility. Brief descriptions of the concepts of sustainable development and development, environmental hazards and proper governance are also given in the text of the article.
The most important natural and human hazards in Mazandaran province are earthquakes, mass movements, floods, fires, droughts, frosts, pollution of water resources, soil erosion, pollution of agricultural products, urbanization and urban development, waste, etc. It brings a lot, attention to earth sciences and the environment can, in addition to preventing risks, accelerate the process of sustainable development.
The research method is descriptive-analytical and based on library and field studies. In order to gather information within the framework of theoretical foundations of research, by referring to library resources (Persian and Latin books, publications, dissertations and reputable foreign sites), the required materials have been collected. Statistics and information related to the development indicators of Mazandaran province have been extracted from the statistics of the Statistics Center of Iran and then examined with SPSS software, Table No. (3). The Cochran's formula was used to determine the sample size. The statistical population in this study is Mazandaran province and the population of the province in the general census of population and housing in 2016, 3,283,582 people, which by placing the total population of the region in the above formula with a probability level of 95% to calculate the sample size by estimating distributions. There were two sentences (Cochran). A total of 384 questionnaires were distributed among residents and officials in the study province, a simple random method.
Based on the appropriate governance indicators in relation to environmental hazards and sustainable development of Mazandaran province, it was evaluated as lower than average (2.78 with theoretical average 3). Based on the results of factor analysis after Warmax matrix period, the participation index shows the role of urban management in increasing people's participation in improving urban environment and reducing social anomalies in Mazandaran province and reducing environmental degradation (with a coefficient of 0.772). , In the index of accountability, accountability of urban managers to the demands and complaints of people about environmental degradation and employment status (with a coefficient of 0.645), in the index of effectiveness and efficiency, the effect of managers' programs on reducing pollution (air, water, etc.) and Increasing the quality of social and infrastructural indicators of sustainable development (0.772) and the variability of the effectiveness of the implemented projects On the part of environmental managers in the cities of Mazandaran province (with a coefficient of 0.720), in the transparency index, what is your level of knowledge about the approval of plans and programs to deal with the effects of environmental hazards on the development indicators of the province (with a coefficient of 0.660) ) And how much do you know about the budgets spent on environmental protection and development and development programs and job creation in the province (with a coefficient of 0.639), in the indicator of responsibility, willingness to accept responsibility in economic, social and environmental fields? What is the level of the neighborhood itself (with a coefficient of 0.592), in the index of the central law, the amount of legal treatment of officials with factors Local and regional pollutants are environmental degrading factors (with a coefficient of 0.8595), in the Justice and Equality Index, the government's attention to dealing with environmental degrading factors in the city and shortening the hand of land grabbers in Mazandaran province (with a coefficient of 0.739) They had a higher operating load.
In relation to the impact of human and natural hazards on sustainable development indicators, which clearly include environmental, economic and social indicators, justice and equality indicators and participation in Mazandaran province are better than other indicators. It shows that the indicators of transparency, accountability and rule of law are less than average in the eyes of the people and are not in a good position in this regard.
Since the early 1990s, the idea of sustainable urban development has been a fundamental and very important issue for decision makers and thinkers. Because it encompasses the historical concept of development and at the same time has become very important in determining the current international, national and regional policies (Pugh, 2004). In recent years, governance has become a hot topic in public sector management, and this is due to the important role that governance plays in determining public health. Therefore, according to environmental resources, good governance means the way in which decision makers promote sustainable development, which includes the protection of the living environment (Shuakrizadeh and Ashrafi, 2011). Governance is the institutional capacity of public organizations to provide goods demanded by the public and to help the citizens of the country or their representatives efficiently, transparently, fairly, and with accountability to limited resources. This definition of governance represents an international organization and development institution such as the World Bank that seeks to support reforms through good governance programs aimed at strengthening the strategic capacity of donor governments while intending to engage civil society. Strengthen sovereignty. (Krueger,2007).
Environmental hazards and ecological crises are the result of the interaction of environmental, economic, cultural, health and even political variables. The scope of these variables is local-spherical, so that no place in the earth is far from its consequences, with the difference that the scope and depth of the crisis is severe and weak (Kaviani rad, 2010). Investigating the effects of environmental hazards in relation to sustainable development with a good governance approach is very important and very important in terms of nature, so the present study with descriptive-analytical approach and based on library and field studies to study the effects of environmental hazards on sustainable indicators of Mazandaran province It has dealt with the characteristics of decent humility. Brief descriptions of the concepts of sustainable development and development, environmental hazards and proper governance are also given in the text of the article.
The most important natural and human hazards in Mazandaran province are earthquakes, mass movements, floods, fires, droughts, frosts, pollution of water resources, soil erosion, pollution of agricultural products, urbanization and urban development, waste, etc. It brings a lot, attention to earth sciences and the environment can, in addition to preventing risks, accelerate the process of sustainable development.
The research method is descriptive-analytical and based on library and field studies. In order to gather information within the framework of theoretical foundations of research, by referring to library resources (Persian and Latin books, publications, dissertations and reputable foreign sites), the required materials have been collected. Statistics and information related to the development indicators of Mazandaran province have been extracted from the statistics of the Statistics Center of Iran and then examined with SPSS software, Table No. (3). The Cochran's formula was used to determine the sample size. The statistical population in this study is Mazandaran province and the population of the province in the general census of population and housing in 2016, 3,283,582 people, which by placing the total population of the region in the above formula with a probability level of 95% to calculate the sample size by estimating distributions. There were two sentences (Cochran). A total of 384 questionnaires were distributed among residents and officials in the study province, a simple random method.
Based on the appropriate governance indicators in relation to environmental hazards and sustainable development of Mazandaran province, it was evaluated as lower than average (2.78 with theoretical average 3). Based on the results of factor analysis after Warmax matrix period, the participation index shows the role of urban management in increasing people's participation in improving urban environment and reducing social anomalies in Mazandaran province and reducing environmental degradation (with a coefficient of 0.772). , In the index of accountability, accountability of urban managers to the demands and complaints of people about environmental degradation and employment status (with a coefficient of 0.645), in the index of effectiveness and efficiency, the effect of managers' programs on reducing pollution (air, water, etc.) and Increasing the quality of social and infrastructural indicators of sustainable development (0.772) and the variability of the effectiveness of the implemented projects On the part of environmental managers in the cities of Mazandaran province (with a coefficient of 0.720), in the transparency index, what is your level of knowledge about the approval of plans and programs to deal with the effects of environmental hazards on the development indicators of the province (with a coefficient of 0.660) ) And how much do you know about the budgets spent on environmental protection and development and development programs and job creation in the province (with a coefficient of 0.639), in the indicator of responsibility, willingness to accept responsibility in economic, social and environmental fields? What is the level of the neighborhood itself (with a coefficient of 0.592), in the index of the central law, the amount of legal treatment of officials with factors Local and regional pollutants are environmental degrading factors (with a coefficient of 0.8595), in the Justice and Equality Index, the government's attention to dealing with environmental degrading factors in the city and shortening the hand of land grabbers in Mazandaran province (with a coefficient of 0.739) They had a higher operating load.
In relation to the impact of human and natural hazards on sustainable development indicators, which clearly include environmental, economic and social indicators, justice and equality indicators and participation in Mazandaran province are better than other indicators. It shows that the indicators of transparency, accountability and rule of law are less than average in the eyes of the people and are not in a good position in this regard.
Zahra Keikha, Javad Bazrafshan, Sirous Ghanbari, Aleme Keikha,
Volume 7, Issue 4 (2-2021)
Volume 7, Issue 4 (2-2021)
Abstract
The occurred disasters in recent decades show that communities and people have getting incrementally vulnerable against the hazards. Therefore, social resiliency is the capacity of change, adaptation, and power of resisting against the social stresses and disasters. This research aims at the spatial analysis of the local community to have effective social indexes on resiliency against the environmental hazards in the Sistan region. The methodology of the research is applied due to its nature and descriptive-analytical with the quantitative-surveying approach based on structural equations modeling (SEM) due to its method. The statistical population of the research includes heads of households in 373 villages that 189 people were selected as a statistical sample in proportion to the population volume by Cochran formula using the stratified random sampling method. Inventory was used as a tool to collect data of research, and validity and reliability of tools were studied and confirmed by confirmatory factor analysis, and Cronbach’s alpha test and composite reliability, respectively. SEM method with partial least squares technical approach and SMART PLS3 software was used to analyze the research data in inferential statistics level. Findings of research showed that the path coefficients of social indexes relationship with social resiliency are significant based on t-value and p-value. In a way that t-value of this path is 11.28 and higher than its critical value, 2.58, and the p-value is lower than 0.05. In addition, WASPAS model was used for the spatial analysis of the effective social factors on the resiliency of the studied villages. This showed that villages of Zahak city have the maximum Qi and villages of Hamoon city have the minimum Qi. Thus, it is concluded that there is a significant relationship between the social indexes and the resiliency of the villagers. Moreover, the volume of the social index effect is high. Since villagers have higher Qi, they have more social resiliency. Hence, it is claimed that the villages of Zahak region have higher social resiliency.
Saeed Fathi, Ph.d. Ali Mohammad Khorshiddoust,
Volume 8, Issue 1 (5-2021)
Volume 8, Issue 1 (5-2021)
Abstract
Zoning and Spatial Analysis of Potential Environmental Hazards
Case study: Silvana District
Abstract
Natural hazards can be considered as one of the most important threats to humankind and nature that can occur anywhere in the world. Natural hazards are one of the main obstacles to sustainable development in different countries and one of the important indicators of the development of world countries is their readiness to deal with natural hazards. Therefore, it is important to pay attention to it and appropriate measures should be taken to reduce the vulnerability of human settlements. Nowadays with increasing population growth, population dynamics and the large number of people exposed to various types of disasters, the need to identify environmental potential hazards and identification of hazardous areas are felt more and more. Meantime, some people may not be aware of potential hazards of their place of residence. So by identifying and evaluating potential hazards and their Risks before the occurrence, we can significantly reduce the severity of the damages and contribute to sustainable regional development. The negative effects of natural disasters can be minimized by the availability of comprehensive and useful information from different areas and Multihazard mapping is one of the most effective tools in this regard.
According to the above mentioned, in this study, the spatial analysis of potential hazards in Silvana district in Urmia County has been studied. This study area due to specific geographic conditions such as position, complexity of topographic and ecological structures, in general, the existence of environmental factors for hazards has been selected as the study area. There have been a number of hazards in the past and assessing of this area is necessary, because of the lack of previous studies. For this purpose, by reviewing various reports and doing field observations, three hazards including Flood, Landslide, and Earthquake are identified as potential hazards of the study area.
For assessing hazards, 12 factors in 6 clusters such as Slope, Aspect (Topographic factors), Lithology, Soil type, Distance to Faults (Geological factors) Precipitation (Climatological factors), River Network Density, Groundwater Resources (Hydrological factors), Land use, Distance to Roads (Human factors), Observed Landslide Density and Seismicity (Historical factors) as the research factors has been selected. For weighting factors, Analytic Network Process (ANP) Method in Super Decisions 2.6.0 software environment has been used. The results of the analysis show that Slope (0.201), Precipitation (0.161), Lithology (0.112), Distance to Faults (0.106), Land use (0.096), Rivers (0.078), Seismicity (0.06), Soil Type (0.055), Landslide Density (0.047), Aspect (0.033), Groundwater (0.03) and Distance to Roads (0.016), Respectively have maximum to minimum relative weight. Then, weighted maps are standardized with using FUZZY functions. For this purpose, Fuzzy membership functions such as Linear, Large and Small has been selected based on each factor. For some factors such as Slope, Aspect, Lithology, Soil type, Rivers density, Land use, Seismicity and Landslide density, Fuzzy linear function has been used. For some others such as Groundwater and Precipitation, Fuzzy large function has been used and for distance to Faults and distance to Roads, Fuzzy small function has been used. Finally, weighted maps were overlay in ArcGIS 10.4.1 environment with Fuzzy Gamma 0.9 operator and potential hazards zoning maps is obtained.
Final results indicate that major parts in the Northwest, West and South of the study area located in high risk zones and 59 percent of the total area exposed to high risk. Based on hazard zoning maps, 44 percent of the area exposed to Flooding, 48 percent exposed to Landslide and 44 percent exposed to Earthquake. Also, 61 percent of the population or 37394 people exposed to one hazard, 7 percent or 3817 people exposed to two hazard and 8 percent or 4914 people exposed to three hazard. According to surveys, only 21 percent of the study area is considered as a low risk area but that does not mean that environmental hazards will never happen in these areas. In general, and based on results, it is concluded that Silvana district has a high potential for environmental hazards. Final results of the research show that potential hazards identifying and preparation of hazard zoning maps can be very useful in reducing damages and achieving sustainable regional development. Therefore, considering the ability of hazard zoning maps to identify areas exposed to risk and assess the type of potential hazards, These analyzes should be considered as one of the most appropriate and useful tools in different stages of crisis management that can be the solution to many problems in preventing and responding to natural disasters and therefore, it is recommended that they be used in the crisis management process.
Keywords: Spatial Analysis, Environmental Hazards, Silvana, ANP Method, Risk
Mr Hossien Rahi Zehi, Dr Mahmood Khosravi, Dr Mohsen Hamidian Pour,
Volume 8, Issue 1 (5-2021)
Volume 8, Issue 1 (5-2021)
Abstract
The Spatio-Temporal Variations of Aerosol Concentration Using Remote Sensing in Sistan and Baluchestan Province (2018 - 2000)
Abstract
Atmospheric particles play an important role in balancing the energy budget of the Earth's surface. The Sistan and Baluchestan province because of the specific geographical conditions during the year is witnessing the spread of dust particles caused by dust storms. This paper investigates the spatial changes of this phenomenon in the region to identify the association of dust accumulation and the reasons for these concentrations. In this study, the AOD Index data of the Aqua and Terra Modis Satellite Sensor (MODAL2_M_AER_OD) with 10 × 10 km spatial resolution were used. Then, by using statistical methods, a spatial analysis was done and the temporal and spatial changes trends at 95% and 99% significance level were performed using the nonparametric Mann-Kendall method. The results showed that the maximum concentration of aerosol in areas such as Zabol, Zahak, Hirmand, Hamoun, Iranshahr, Bampour, Jazmurian basin, Chabahar, and Konarak. On average, the highest variations in aerosol concentration were in the southern regions of the province include Dashtiari, Polan, and Chabahar, and the least in the northern part of Polan, Chabahar, Konark, and Bampour areas. The trend of changes was evaluated at two significant levels of 95 and 99%. The results of this section showed that the AOD had a positive and increasing trend in June, July, and August in the areas of Dalgan, Iranshahr, Bampour, Bazman, Mirjaveh, Nokabad, Zahedan, Nosratabad, Zaboli, Qasrqand, Irandegan, and Sib-va-Soran Plain and areas such as Korin, Zabol, Zahak, Sirkan (Bamposht), Hamoun have a negative and decreasing trend. The average changes in aerosol concentration in June, July, and August show a significant increase in the aerosol concentration from 2015 to 2018 up to 0.8.
Keywords: Environmental Changes, Dust, Environmental Hazards, Climate.
Asadollah Hejazi, , Adnan Naseri,
Volume 8, Issue 2 (9-2021)
Volume 8, Issue 2 (9-2021)
Abstract
Zoning the possibility of landslides downstream of Sanandaj Dam
1-Introduction
The purpose of this study is to select the best model and identify landslide risk areas in the downstream basins of Sanandaj Dam. Every year, mass movements in the region cause damage to roads, power lines, natural resources, farms and residential areas, and increase soil erosion. Kurdistan province, with its mostly mountainous topography, high tectonic activity, diverse geological and climatic conditions, has the most natural conditions for mass movements. According to the available statistics, this province is the third province in terms of landslides after Mazandaran and Golestan. (Naeri, &Karami, 2018). The Gheshlagh River Basin is a mountainous region with a north-south trend. In terms of construction land, it is located on the structural zone of Sanandaj-Sirjan. The study area with an area of 970.7 square kilometers is located downstream of Sanandaj Dam. The city of Sanandaj is being studied within the region. Due to the type of climate and morphological processes, effective parameters are provided for landslides in the geography of the region.
2-Methodology
In this study, 9 effective factors for landslides, including slope, slope direction, fault distance, road distance, waterway distance, lithology, land use and precipitation were used. Using Google Landsat 8 ETM satellite imagery, Google Earth software identified 237 slip points. Then, the coordinates of the slip points were transferred to the Arc GIS software and a map of the landslide distribution area in this environment was prepared. Also, in this study, 89 non-slip points were prepared for use in the training and testing stages of Persephone neural network inside slopes less than 5 degrees. Artificial neural networks are made up of a large number of interconnected processing elements called neurons that act to solve a coordinated problem and transmit information through synapses. Neural networks begin to learn using the pattern of data entered into them. Learning models, which is actually determining their internal parameters, is based on the law of error correction. In this method, by correcting the error regularly, the best weights that create the most correct output for the network are identified. The neurons are in the form of an input layer, an output layer, and an intermediate layer. ahp includes a weighting matrix based on pairwise comparisons between factors and determines the level of participation of each factor in the occurrence of landslides. In this model, a large number of factors can be involved and the weight of each factor can be obtained using expert opinion.
3-Results
According to the results of the high-risk class neural network model, which occupies 31% of the basin area, it is the widest risk zone in the region. The middle class also accounts for more than 29 percent of the area, followed by the low-risk class. The results of the AHP model show that the middle class, with 32% of the area, has the highest dispersion in the region, the low-risk class and then the high-class are in the next position. The AHP model was used to prioritize the parameters affecting the landslide. The parameters of slope, lithology and land use play the most important role in the occurrence of landslides, respectively, and have the least role for slope direction, distance from fault and height. The results of the models used are consistent with the reality of the region's wide-risk hazards, and high-risk areas based on the models used are mostly located in the west and southwest of the basin. These areas correspond to the mountain unit and the steep slope. Based on the results of AHP model, the impact of human factors in the occurrence of landslides is weaker than the natural factors of the region and human factors play a stimulating and aggravating role in primary factors. Five methods for error detection were used to evaluate the models used
4-Discussion and conclusion
.Due to the sensitivity of unstable slopes in the region, any planning to change the use and construction that increases the weight of the load on unstable slopes should be done in terms of geomorphological and geological conditions of the region.
Keywords: hazard zoning, landslide, neural network, AHP. Sanandaj Gheshlagh Watershed
Mohammadreza Jafari, Shamsullah Asgari,
Volume 8, Issue 2 (9-2021)
Volume 8, Issue 2 (9-2021)
Abstract
One of the causes of environmental hazards is the change in the pattern of surface water flow in floodplains following the construction of flood Spreading networks. The purpose of this study is to prepare a zoning map of vulnerable areas of the flood Spreading station of Musian plain in Ilam province after the implementation of the aquifer project in this plain. To prepare this map, five factors influencing the change in flow pattern including elevation, slope, flow direction, geological formations, and landuse change were examined. Then, in the GIS environment, each class of the mentioned factors was given a score of zero to 10 based on the range and the corresponding weight layers were created. Then, by combining the created weight layers, the vulnerability zoning map of the area was created based on 5 classes: very low, low, medium, high and very high. The results showed that the most important threat and danger factor is the concentration of waterways behind erosion-sensitive embankments. Also, the study area in terms of vulnerability includes three classes with medium risk, high and very high and covers 16, 62 and 22% of the area, respectively. Flood and upland Spreading areas, risk areas and lowland lands are the most vulnerable parts of the basin in terms of floods and sedimentary deposits.
Zahra Mosaffaei, Ali Jahani, Mohammad Ali Zare Chahouki, Hamid Goshtasb Meygoni, Vahid Etemad,
Volume 8, Issue 3 (12-2021)
Volume 8, Issue 3 (12-2021)
Abstract
Risk modeling of plant species diversity and extinction in Sorkheh_hesar National Park
Zahra Mosaffaei1, Ali Jahani2*, 3MohammadAli ZareChahouki, 4Hamid GoshtasbMeygoni, 5Vahid Etemad
1 Masters of Natural Resources Engineering, Environmental Sciences, College of Environment, Karaj
*2Associate Professor, Department of Natural Environment and Biodiversity, College of Environment, Karaj.
3 Professor, Department of Restoration of arid and mountainous regions, University of Tehran, Karaj
4 Associate Professor, Department of Natural Environment and Biodiversity, College of Environment, Karaj
5 Associate Professor, Department of Forestry and Forest Economics, University of Tehran, Karaj
Abstract
Full identification of hazards and prioritizing them for non-harm to nature is one of the first steps in natural resource management. Therefore, introducing a comprehensive system of evaluation, understanding, and evaluation is essential for controlling hazards. This study aimed to model and predict environmental hazards following increased degradation in natural environments by ANN. Thus, 600 soil and vegetation samples were collected from inhomogeneous ecological units. Soil samples were prepared by strip transect method according to soil depth in four profiles (5, 10, 15, 20 cm). Vegetation samples were also collected using a minimum level method using 2 2 square plots according to the type, density, and distribution of vegetation. Sampling was done in two safe zones and other uses were modeled using ANN in MATLAB environment. The optimal model of multilayer perceptron with two hidden layers, sigmoid tangent function and 19 neurons per layer and coefficient of determination of 0.90. The results of sensitivity analysis showed that soil moisture content would be effective in decreasing biodiversity and flood risk as well as increasing the risk of extinction of endemic species in the region, and then the apparent and true gravity and soil porosity and distance from the road play a key role in the degradation of cover. Vegetation has increased flooding and extinction risk. Therefore, it is recommended that measures related to soil and vegetation restoration in this park be taken to reduce future damages as soon as possible.
Keywords: Modeling, Artificial Neural Network, Environmental Hazards, National Park, Vegetation
Dr Raoof Mostafazadeh, Vahid Safariyan-Zengir, Khadijeh Haji,
Volume 8, Issue 4 (3-2022)
Volume 8, Issue 4 (3-2022)
Abstract
Abastract
Introduction
Road accidents is the outcome of driver behavior, road condition, vehicle status, and environmental factors. Therefore, identification and assessment of effective parameters on road accidents can be considered as an appropriate way to reduce the accident events, driving violations and increase the road safety. Determining the effects of meteorological factors on the road accident events has gained more attention in recent years.
The The main objective of this study was to investigate the relationship between the number of road accidents and the meteorological variables in the intercity road of Grmi-Ardabil in the Barzand route.
Methodology:
In this regard, the effects of climatic factors (including rainfall amount, the minimum absolute temperature, and the number of frost days) on the frequency of perilous events were analyzed. The data of accident events (in recent 4 years) were obtained from the trooper department of Ardabil Province along with the meteorological parameters of Germi station through a 11-year period. The statistical tests were performed using R programming software through statistical analysis.
Findings and Discussion:
The results showed that the majority of accidents were occurred in winter season which is in consistent with the frequency of frost days and also corresponded to the absolute minimum temperature. According to the results, the highest significant positive correlation at (R2= 0.43) was observed between the number of injured people and frost days. In addition, the relationship between the absolute minimum temperature and the number of were identified as significant negative correlation.
Conclusion:
As a concluding remark, the poor road conditions caused by climate element can be considered increasing the frequency of accident events. Accordingly, the proper strategies related to behavior change could be
considered in setting the rules and regulations to reduce the accidents and the number of injuries.
Keywords: Climatic hazards, Correlation analysis, Frost days, Minimum absolute temperature, Germi-Ardabil road
Ms Paniz Ashrafi, Dr Behnod Barmayehvar, Dr Ehsan-Allah Eshtehardian,
Volume 9, Issue 2 (9-2022)
Volume 9, Issue 2 (9-2022)
Abstract
Considering the increase in housing construction in developing societies such as Iran, it is necessary to address the issue of reducing construction accidents, especially in metropolises, and related safety measures with the help of emerging technologies. Therefore, the main goal of the current research is to investigate the use of Internet of Things to monitor and control high-risk points in order to reduce accidents and improve safety in the spaces of construction site in Tehran.
In this applied research, first, a library study was conducted regarding the concept and application of Internet of Things in the safety field of the construction industry. Then, high risk points and activities were identified. After that, in the field study phase, this list was corrected and completed by 52 competent building safety consultants. After that, ten semi-structured interviews were conducted with safety experts and knowledgebale in the field of IoT. Therefore, effective solutions based on Internet of Things were extracted to control and monitor high risk points. Also, in this regard, the current situation and required platforms were explained from the aspects of technology, organization, cost and outsourcing.
In fact, the main findings of this research, in the form of a conceptual model, show that paying attention to the stages of choosing the incident, choosing the desired point and activity, determining the appropriate solution for the determined situation (monitoring the amount of movement and health of the structure, monitoring the proximity of flammable materials with other materials, monitoring the proximity of people and machines and preventing the continuation of movement and determining the limits around the openings) and checking the required platforms (infrastructure, support, accreditation, culture, budget, employers and law), respectively, in order to design and implement IoT-based safety systems in the spaces of construction sites is vital.
Dr Alireza Mohammadi, Dr Lotfollah Maleki, Mr Ghasem Fathi,
Volume 9, Issue 4 (3-2023)
Volume 9, Issue 4 (3-2023)
Abstract
Spatial analysis models provide a single model and solution to solve various problems in the field of study, one of the applications of these models is in measuring urban risks. In recent years, with the occurrence of various crises in urban communities, the urban management system and development plans are seeking access to models of prevention and dealing with these crises. The purpose of this research is to review the literature about the use of spatial analysis models in measuring urban risks in a meta-analytical way, so this research is conducted by reviewing and summarizing foreign articles (research statistical community) in relation to this issue in order to identify, analyze and Analyzing and summarizing the solutions of the investigated backgrounds.
The statistical population is discussed with four standard criteria of spatial analysis, including description and identification of hazard dispersion, hazard dispersion argument, interpolation, and spatial planning. The statistical population is research, studies, and articles indexed in Sciencdirect, Willey, Web of Science databases in the period 2021-2000. Out of 99 articles, 78 articles have been selected and analyzed by screening method according to research objectives and indicators. The analysis was performed in two ways: descriptive statistics in SPSS software and inferential statistics in CMA2 comprehensive meta-analysis software.
The results indicate that in the component of hazard dispersion descriptions, most of the researches in their used models have not been able to provide a tangible and appropriate general description, but in the three components of hazard dispersion, interpolation, and spatial planning of urban hazards based on score The average effect size, the applied models used in the research, have been able to provide a proper justification and tangible results with the applied model of spatial analysis in their studies.
Ms. Sousan Heidari, Dr. Mostafa Karimi, Dr. Ghasem Azizi, Dr. Aliakbar Shamsipour,
Volume 9, Issue 4 (3-2023)
Volume 9, Issue 4 (3-2023)
Abstract
Explaining the spatial patterns of drought intensities in Iran
Abstract
Recognition of spatial patterns of drought plays an important role in monitoring, predicting, confronting, reducing vulnerability, and increasing adaptation to this hazard. This study aims to identify the spatial distribution and analyze the spatial patterns of annual, seasonal, and monthly drought intensities in Iran. For this purpose, the European center Medium-Range Weather Forecast (ECMWF) data for the period 1979-2021 and the ZSI index were used to extract the drought intensities. To achieve the research goal and explain the spatial pattern of the frequency of drought intensities (Extreme, severe, moderate, and weak), spatial statistical methods such as global Moran’s I, Anselin local Moran’s Index, and hot spots were used. The results of the global Moran’s I showed that with increasing intensity, the spatial distribution of drought events has become clustered. The spatial distribution of the local Moran’s Index and hot spots also confirms this. Very clear contrast was observed in the local clusters of high (low) occurrence as well as hot (cold) spots of severe (Extreme) yearly droughts in the south, southeast, and east. In autumn, weak to Extreme droughts show a southeast-northwest pattern. But in spring and winter, the spatial pattern of drought is very strong as opposed to severe and moderate drought. Despite the relatively high variability of maximum positive spatial Autocorrelation of severe and Extreme monthly droughts, their spatial pattern is almost similar. The spatial clusters of severe and very severe droughts in the northwest, northeast, and especially on the Caspian coast, are a serious warning for the management of water resources, especially for precipitation-based activities, such as agriculture.
Introduction
Drought or lack of precipitation over some time is the most widespread natural hazard on the earth compared to its long-term average. This risk negatively affects various sectors such as hydropower generation, health, industry, tourism, agriculture, livestock, environment, and economy. To reduce these negative or destructive effects, it must be determined how often drought occurs during the period and in which areas it is most severe. Doing so requires determining the characteristics of the drought. These characteristics include area, intensity, duration, and frequency of drought. Discovering the geographical focus, recognizing the pattern governing the frequency of occurrence and temporal-spatial distribution as well as changes in the dynamics of this hazard facilitate an important role in drought monitoring, early warning, forecasting, and dealing with these potential hazards; this information can be used to create a drought plan by providing analysts and decision-makers with ideas about drought, helping to reduce the negative and vulnerable effects and ultimately make it easier to protect or replace for greater adaptation. Many researchers have been led by these approaches to the use of statistical analysis. Numerous studies have been conducted in the study of climatic phenomena such as drought with space statistics techniques in various regions, including China, India, South Korea, and even Iran. Part of the domestic research on spatial patterns of drought is without the use of spatial statistics and a limited number of others who have used these analyzes have only studied the overall intensity of drought and have not studied the spatial patterns of different drought intensities. The main purpose of this study is to identify the distribution and spatial patterns of drought intensities in Iran using spatial analysis functions of spatial statistics based on the frequency of drought intensities (Extreme, severe, moderate, and weak) with yearly, seasonal and monthly multi-scale approach. Therefore, this study will answer the questions: a) What is the spatial distribution of drought intensity data in Iran? And b) What is the variability of spatial patterns of Iranian droughts at different time scales?
Material &Method
ERA5 monthly precipitation data for a period of 43 years from 1979 to 2021 were used for this study. an array of dimensions of 78×59×504 of data were formed in MATLAB software in which 78×59 is the number of nodes with a spatial resolution of 0.25 degrees and 504 represents the month. After creating the database, the ZSI index was used to calculate the severity of drought in annual, seasonal, and monthly comparisons. Finally, to achieve the research goal and explain the spatial pattern governing the frequency of drought intensities (Extreme, severe, moderate, and weak), spatial statistical methods such as global Moran’s I, Anselin local Moran I and hot spots was used.
Discussion of Results
Due to its ecological conditions, geographical location, and location in an arid and semi-arid region of the world, Iran is among the most vulnerable countries due to natural hazards, including drought. It has experienced many severe droughts in the last century. The occurrence of drought and its effects is one of the major challenges of water resources management in this century. The results of the Global Moran’s Index for all three annual, seasonal, and monthly scales showed a highly clustered pattern of drought events in the country. Spatial clustering of the occurrence of severe and Extreme yearly droughts in the eastern, southeastern, and southern regions is also an interesting result. These conditions are due to low precipitation and high spatial variation coefficient in these areas. This contrast of spatial clusters of drought intensities indicates the relationship between drought and temporal-spatial anomalies of precipitation so that with increasing precipitation, spatial variability of precipitation decreases, and consequently spatial homogeneity of precipitation increases. severe and moderate-intensity spots in the south-southeast in autumn and spring can be affected by fluctuations in the beginning and end of the monsoon season in South Asia due to the high variability of atmospheric circulation at the beginning and end of precipitation in these areas. Some studies have also shown the relationship between precipitation in these areas and the monsoon behavior of South Asia. Extreme drought events in winter and spring have had a positive spatial correlation pattern in the southwest, west, and northwest. However, precipitation at this time of year is concentrated in these areas. Warm clusters or concentrations of very severe drought events in the northern strip of the country, especially in the Caspian region, can be due to the high variability of precipitation at the beginning of the annual precipitation season (late summer and early autumn). Observations of these conditions in the northern strip indicate that an event with a high frequency of severe droughts, even in rainy areas, should not be unexpected. Spatial clusters of Extreme, severe, moderate, and weak drought every month using both local Moran and hot spots statistics show the fact that in Iran, the most severe droughts have occurred in the western, northwestern, and coastal areas of the Caspian Sea. However, the absence of severe droughts or spatial clusters has been the occurrence of low drought in the southeast and to some extent in the south. On a yearly scale, the south, southeast, and east have played a significant role in the spatial cluster of severe and extreme droughts. So that these areas of the country have had positive spatial solidarity. However, in these areas, negative spatial correlation prevailed in the autumn for severe drought. This may indicate an anomaly and a tendency to concentrate more precipitation in Iran, as well as many changes in seasonal and local precipitation regimes. According to the research results, a high incidence of severe and extreme drought on all three scales (monthly, seasonal and annual) even in the wettest climate of the country (northern Iran, especially the southern shores of the Caspian Sea) shows that High-intensity droughts can occur in all parts of the country, regardless of the weather conditions.
Keywords: Natural hazards, spatial patterns, Moran statistics, spatial autocorrelation, hot spots
Dr Mohammad Mahdi Hosseinzadeh, Dr Ali Reza Salehipor Milani, Mis Fateme Rezaian Zarandini,
Volume 10, Issue 1 (5-2023)
Volume 10, Issue 1 (5-2023)
Abstract
Introduction
A flood is a natural disaster caused by heavy rainfall, which causes casualties and damage to infrastructure and crops. Trend of floods in the world increasing due to climate change, changing rainfall patterns, rising sea levels in the future, and in addition, population growth and urban development and human settlements near river have caused floods to become a threat to humans. One of the most important and necessary tasks in catchments is to prepare flood risk maps and analyze them. In recent decades, researchers have been using remote sensing techniques and geographic information systems to obtain flood risk maps in an area. Due to the numerous floods that have occurred in the Neka river catchment, it is necessary to conduct a study entitled zoning of flood sensitivity in Neka river catchment for more effective management in this area.
Materials and methods
Study area: Neka river catchment area with an area of 1922
To study the flood zoning of the area using a multi-criteria decision model, 1: 25000 maps of the surveying organization and a digital elevation model with a resolution of 12.5 meters (Alos Palsar) were extracted. In order to study the flood risk in Neka river, 4 criteria of height, distance from the river, land use and slope have been used. In the present study, modeling and preparation of flood risk zoning map in 4 stage including descending valuation, normalization of each class, normalized index weight and integration of criteria has been done by the following linear weighting method. Performing linear weighting operations depends on the weighted average of a number of selected parameters in the opinion of the expert. According to the weight assigned to each criterion based on the expert opinion, each of the criteria was multiplied by the assigned weight and at the end the criteria were added together and the final zoning map was obtained.
Results and Discussion
In this study, using a multi-criteria decision-making system model, a flood risk zoning map in the Neka river catchment was prepared. According to the weight assigned to each criterion based on expert opinion, the final risk probability map has a value between 0.02 to 0.2, which is ultimately divided into 5 classes in terms of flood risk. Value range 0.02 to 0.06 component of very low risk zone, range 0.08 to 0.11 component of low-risk zone, range 0.11 to 0.13 component of medium-risk zone, range 0.13 to 0.16 component of high-risk zone, and finally domain 0.16 to 0.20 components of the area with very high risk potential have been obtained. According to the final divisions in the flood risk zoning map of the catchment area, a safe area means areas where the probability of flooding is very low and close to zero, and in contrast, the area with a high and very high risk potential for flooding has the probability of high-risk floods. According to the final flood risk zoning map, about 982
Conclusion
The results obtained from the model indicates that the highest risk of flooding points are located in the western parts of the Neka catchment area and the end of the catchment area that reach the city of Neka. According to the research findings, the most important factors in increasing the risk of floods were the slope in this area and the distance from the drainage network. According to the results of the model, a large area of the basin is a component of high risk zone, that means the Neka river watershed has a high potential for floods. Evidence and documented reports show that the Neka river Basin has experienced several floods in the last two decades. The major part of the occurrence of floods is due to the natural conditions of the basin, thus it is necessary to reduce flood damage by changing the locations of various land uses based on flood vulnerability maps. Using multi-criteria decision making method can be used to prepare flood risk zoning maps in basins that do not have hydrometric data; It is also a more cost-effective method in terms of time. One of the important issues in the final result of this model is due to the weight of the layers, which should be used by experts, who are familiar with the region and this method and adapt to field evidence.
Keyworlds: Flood, Multi-criteria decision making system(MCDA), Hazard zoning, Nekarod, Natural hazard.
Dr Abdolmajid Ahmadi, ,
Volume 10, Issue 1 (5-2023)
Volume 10, Issue 1 (5-2023)
Abstract
Extended abstract
Landslide risk zoning is one of the basic measures to deal with and reduce the effects of landslides. Vernesara watershed is one of the areas where many landslides have been observed in different parts of it. In this research, in order to zone the risk of landslides using the entropy index, first the ranges of landslides were determined, then the effective factors in the occurrence of range movements were prepared in the ArcGIS software environment, and a landslide susceptibility map of the studied area was prepared. . The prioritization of effective factors using Shannon's entropy index showed that the slope layers, land use, surface curvature, topographic humidity index and topographic position index had the greatest effect on the occurrence of landslides in the region. Also, zoning landslide sensitivity with the mentioned model and evaluating its accuracy using the ROC curve shows the very good accuracy of the model (79.6 percent) with a standard deviation of 0.0228 for the studied area. The zoning map shows that the low-risk areas cover only 13% of the area and more than 56% of the area is in the area with high risk of landslides, which indicates the high potential of the area in the occurrence of landslides. . Construction at a distance from fault lines, waterways and the steep Asmari Formation and safety of communication routes are the most important measures to reduce the amount of damage caused by landslides in Vernesara watershed.
Key words: natural hazards, landslide, entropy, folded Zagros.
Masoomeh Hashemi, Ezatallah Ghanavati, Ali Ahmadabadi, Oveis Torabi, Abdollah Mozafari,
Volume 10, Issue 2 (9-2023)
Volume 10, Issue 2 (9-2023)
Abstract
Introduction
Earthquakes as one of the most important natural disasters on earth, have always caused irreparable damage to human settlements in a short period of time. Severe earthquakes have led to the idea of developing an infrastructure plan to reduce the risks and damages caused by it. The urban water supply system is the most important critical infrastructure that is usually damaged by natural disasters, particularly earthquakes and floods; hence, the function of the pipelines of the water system determines the degree of resilience and design of the infrastructure against multiple natural and man-made hazards. Considering the inability to prevent earthquakes and the inability of experts to accurately predict the time it is necessary to know the status of earthquake-structure and seismicity in Tehran to determine the amount of earthquake risk in order to make the necessary planning for structural reinforcement. Theoretical and field studies of tectonic seismicity in the Tehran area show that this city is located on an earthquake-prone area around the active and important faults of Masha, north of Tehran, Rey and Kahrizak. The occurrence of 20 relatively severe earthquakes illustrates this claim. Regarding the location of faults in Tehran city, it is necessary to assess the vulnerability of Tehran water facilities.
Research Methodology
The present study is a practical-analytic one. Considering the severity of earthquake damages, it is necessary to conduct earthquake hazard zonation studies in different urban areas and to determine important indicators of damage assessment such as maximum ground acceleration, maximum ground speed, maximum ground displacement. Three indices were considered for mapping earthquake seismic zones and their integration into the GIS presented a seismic hazard map. In the analysis of earthquake risk, it is necessary to evaluate two indicators of risk and vulnerability. To prepare the general hazard power mapping the weights obtained from the ANP model were applied to the existing raster layers via the Raster Calculator command. In this way, the standardized layers are multiplied separately by their respective weights and finally overlapped. In order to evaluate the vulnerability, a series of evaluation indices are introduced and ANP techniques are used. The relative value of each index is then calculated using the multivariate approach using the SAW technique. In order to calculate the earthquake risk based on R = H * V relation, the values of these two components were multiplied. This calculation was performed in GIS software on the risk and vulnerability raster layer and the final result of this calculation was displayed on the map.
Description and interpretation of results
In this study, we tried to estimate the relative risk and risk of seismic hazard on the water supply lines in Tehran, using available data and scientific methods, and map the risk level. These lines should be prepared first by the amount of earthquake hazard risk and then by the risk map, to estimate the earthquake risk on the water supply network. first the earthquake risk then the status of the hazard lines should be calculated. The vulnerability of the water supply lines was calculated using the ANP model by multiplying the total potential hazard risk then substrate transfer network vulnerability risk map obtained transmission network. The highest risk was in the west and north of Tehran. The maps showed the risk potential and the vulnerability of the lines. These areas had high seismic potential and the density of the lines was higher in these areas. Water transmission facilities are at risk and earthquake hazards may be affected by damage to the transmission lines, drinking water to a large population will be difficult, as well as performing necessary zoning to prevent future expansion of the facility in place. These analyzes are a prelude to applying corrective techniques to pipelines to reduce their vulnerability and prevent newly created pipelines from locating in vulnerable areas. Since the results of this study are risk maps along the route of the water supply lines, so in order to prepare a risk control program, we can identify the high risk pipeline map and identify the pipeline vulnerability. And, depending on its location, provided an appropriate prevention and control plan for the conditions surrounding the pipeline environment.
Earthquakes as one of the most important natural disasters on earth, have always caused irreparable damage to human settlements in a short period of time. Severe earthquakes have led to the idea of developing an infrastructure plan to reduce the risks and damages caused by it. The urban water supply system is the most important critical infrastructure that is usually damaged by natural disasters, particularly earthquakes and floods; hence, the function of the pipelines of the water system determines the degree of resilience and design of the infrastructure against multiple natural and man-made hazards. Considering the inability to prevent earthquakes and the inability of experts to accurately predict the time it is necessary to know the status of earthquake-structure and seismicity in Tehran to determine the amount of earthquake risk in order to make the necessary planning for structural reinforcement. Theoretical and field studies of tectonic seismicity in the Tehran area show that this city is located on an earthquake-prone area around the active and important faults of Masha, north of Tehran, Rey and Kahrizak. The occurrence of 20 relatively severe earthquakes illustrates this claim. Regarding the location of faults in Tehran city, it is necessary to assess the vulnerability of Tehran water facilities.
Research Methodology
The present study is a practical-analytic one. Considering the severity of earthquake damages, it is necessary to conduct earthquake hazard zonation studies in different urban areas and to determine important indicators of damage assessment such as maximum ground acceleration, maximum ground speed, maximum ground displacement. Three indices were considered for mapping earthquake seismic zones and their integration into the GIS presented a seismic hazard map. In the analysis of earthquake risk, it is necessary to evaluate two indicators of risk and vulnerability. To prepare the general hazard power mapping the weights obtained from the ANP model were applied to the existing raster layers via the Raster Calculator command. In this way, the standardized layers are multiplied separately by their respective weights and finally overlapped. In order to evaluate the vulnerability, a series of evaluation indices are introduced and ANP techniques are used. The relative value of each index is then calculated using the multivariate approach using the SAW technique. In order to calculate the earthquake risk based on R = H * V relation, the values of these two components were multiplied. This calculation was performed in GIS software on the risk and vulnerability raster layer and the final result of this calculation was displayed on the map.
Description and interpretation of results
In this study, we tried to estimate the relative risk and risk of seismic hazard on the water supply lines in Tehran, using available data and scientific methods, and map the risk level. These lines should be prepared first by the amount of earthquake hazard risk and then by the risk map, to estimate the earthquake risk on the water supply network. first the earthquake risk then the status of the hazard lines should be calculated. The vulnerability of the water supply lines was calculated using the ANP model by multiplying the total potential hazard risk then substrate transfer network vulnerability risk map obtained transmission network. The highest risk was in the west and north of Tehran. The maps showed the risk potential and the vulnerability of the lines. These areas had high seismic potential and the density of the lines was higher in these areas. Water transmission facilities are at risk and earthquake hazards may be affected by damage to the transmission lines, drinking water to a large population will be difficult, as well as performing necessary zoning to prevent future expansion of the facility in place. These analyzes are a prelude to applying corrective techniques to pipelines to reduce their vulnerability and prevent newly created pipelines from locating in vulnerable areas. Since the results of this study are risk maps along the route of the water supply lines, so in order to prepare a risk control program, we can identify the high risk pipeline map and identify the pipeline vulnerability. And, depending on its location, provided an appropriate prevention and control plan for the conditions surrounding the pipeline environment.
Farzin Mahmoudi, Hamed Ghadermazi, Dr Leila Mafakheri,
Volume 10, Issue 3 (9-2023)
Volume 10, Issue 3 (9-2023)
Abstract
Introduction
Every year, natural hazards occur with great severity and sometimes they destroy people completely Today, science has proven that natural hazards cannot be avoided. He simply considered a natural event and did not pay attention to their complex causes. Most of these causes are attributed to a combination of socio-economic factors. But it is possible to reduce their consequences by carefully planning against such accidents. When these hazards and disasters have a human aspect and affect humans, human activity and human environment, they are introduced as crisis.
According to the statistics of the Food and Agriculture Organization of FAO, 5-15% of agricultural products are lost annually due to damage caused by frost and frost, this number reaches more than 40% for some sensitive garden products, especially almonds, pistachios and apricots. . The amount of damage caused by this complication in Iran is more than 500 million dollars. Rural settlements suffer the most damage after a drought. Thus, there is a significant relationship between the risk management of agricultural activities with most environmental components and natural disasters such as drought, flood, frost, etc. up to the 99% confidence level. In order to reduce the effects of natural hazards in rural areas, there are various strategies that can be used to manage the risk of natural hazards , diversification of agricultural productio, contract farming and increasing farmers' awareness of natural hazards.
Gardens are one of the most important sources of livelihood in rural areas in Tuysarkan city in Hamadan province. Tuysarkan city has 7600 hectares of garden lands, which includes 14% of all gardens in Hamadan province. Due to its geographical location, weather conditions and geological structure, this city is exposed to various natural hazards. Among them, we can mention drought, land subsidence, frost and earthquake. Identifying natural hazards in Tuiserkan city and the effects of these hazards, as well as the actions of the local community to reduce existing hazards, are among the most important goals of this research.
Research Method
In the current research, we tried to use different methods so that the subject can be better investigated from different angles of research. This research is applied in terms of purpose and based on a descriptive-analytical research plan and is considered analytical-exploratory in nature. The research data has been collected through questionnaires and official statistics of institutions such as Iran Water Resources Management Company and the country's Meteorological Organization. Data analysis has been done descriptively and analytically using Excel and GIS software.
Research Results
The results of the research show that the most important hazards in the field of horticulture in the central part of Tuiserkan are frost in the first place and drought and hail in the second and third places. Also, other results show that the most important risk that affects the livelihood and income of the local community is the annual frost of gardens, which has caused the migration of some family members, and the amount of income is also affected by this risk. Regarding the solutions proposed by the local community to reduce the effects of natural hazards on walnut orchards, providing financial facilities, using information technology, and planting cold-resistant species were among the most important solutions proposed by the local community. Regarding the analysis of open questions and conducted interviews, Netaj shows that the most important measures to reduce the effects of natural hazards (freezing, drought and hail) on walnut orchards are: heating the orchard environment, using resistant and using drip irrigation. Also, the evaluation of the analysis of local knowledge and the experience of the past regarding measures to reduce the effects of frost on walnut orchards shows that the actions of the past are not very popular with the current generation and they are doing the same thing that the past did. With this difference, the ancients believed more in luck and destiny than in practical action. Finally, from the point of view of the local community, the best measure to reduce the effects of frost on the walnut orchards in the central part of Tuiserkan is genetic modification of the orchards and cultivation of resistant species.
Every year, natural hazards occur with great severity and sometimes they destroy people completely Today, science has proven that natural hazards cannot be avoided. He simply considered a natural event and did not pay attention to their complex causes. Most of these causes are attributed to a combination of socio-economic factors. But it is possible to reduce their consequences by carefully planning against such accidents. When these hazards and disasters have a human aspect and affect humans, human activity and human environment, they are introduced as crisis.
According to the statistics of the Food and Agriculture Organization of FAO, 5-15% of agricultural products are lost annually due to damage caused by frost and frost, this number reaches more than 40% for some sensitive garden products, especially almonds, pistachios and apricots. . The amount of damage caused by this complication in Iran is more than 500 million dollars. Rural settlements suffer the most damage after a drought. Thus, there is a significant relationship between the risk management of agricultural activities with most environmental components and natural disasters such as drought, flood, frost, etc. up to the 99% confidence level. In order to reduce the effects of natural hazards in rural areas, there are various strategies that can be used to manage the risk of natural hazards , diversification of agricultural productio, contract farming and increasing farmers' awareness of natural hazards.
Gardens are one of the most important sources of livelihood in rural areas in Tuysarkan city in Hamadan province. Tuysarkan city has 7600 hectares of garden lands, which includes 14% of all gardens in Hamadan province. Due to its geographical location, weather conditions and geological structure, this city is exposed to various natural hazards. Among them, we can mention drought, land subsidence, frost and earthquake. Identifying natural hazards in Tuiserkan city and the effects of these hazards, as well as the actions of the local community to reduce existing hazards, are among the most important goals of this research.
Research Method
In the current research, we tried to use different methods so that the subject can be better investigated from different angles of research. This research is applied in terms of purpose and based on a descriptive-analytical research plan and is considered analytical-exploratory in nature. The research data has been collected through questionnaires and official statistics of institutions such as Iran Water Resources Management Company and the country's Meteorological Organization. Data analysis has been done descriptively and analytically using Excel and GIS software.
Research Results
The results of the research show that the most important hazards in the field of horticulture in the central part of Tuiserkan are frost in the first place and drought and hail in the second and third places. Also, other results show that the most important risk that affects the livelihood and income of the local community is the annual frost of gardens, which has caused the migration of some family members, and the amount of income is also affected by this risk. Regarding the solutions proposed by the local community to reduce the effects of natural hazards on walnut orchards, providing financial facilities, using information technology, and planting cold-resistant species were among the most important solutions proposed by the local community. Regarding the analysis of open questions and conducted interviews, Netaj shows that the most important measures to reduce the effects of natural hazards (freezing, drought and hail) on walnut orchards are: heating the orchard environment, using resistant and using drip irrigation. Also, the evaluation of the analysis of local knowledge and the experience of the past regarding measures to reduce the effects of frost on walnut orchards shows that the actions of the past are not very popular with the current generation and they are doing the same thing that the past did. With this difference, the ancients believed more in luck and destiny than in practical action. Finally, from the point of view of the local community, the best measure to reduce the effects of frost on the walnut orchards in the central part of Tuiserkan is genetic modification of the orchards and cultivation of resistant species.
Saeedeh Koohestani, Bijan Sayyafzadeh, Abdolreza Sarvghad Moghadam, Mahdi Sharifi,
Volume 10, Issue 4 (12-2023)
Volume 10, Issue 4 (12-2023)
Abstract
By increasing the number of process industrial plants because of societies necessity to their productions, a new branch of accidents caused by various occurred process failures and their effect on the societies and environment and economy has been introduced. Beside it, the increase of the accidents because of natural hazards effect on the industrial plants and their huge costs to the societies and governments and high vulnerability of plants and urbanized territory to the branch of the accidents, increased the attention to this type of accidents. However, in many parts of the world still do not pay attention seriously to this issue and by considering them as very low probability accidents, eliminate paying attention and accepting the responsibility of them while the frequency of such accidents is under growing! In this article according to the existing statistics, an evaluation and comparison of consequences of natural hazards that caused NaTech events has been done. The purpose of the NaTech events is process events that triggered because of natural hazards that are known as events with low probability and high consequences that can affect a wide area and cause huge accidents associated with domino effects. After introducing and categorizing NaTech events, a comparison of their distribution and consequences of these events in Iran and the world has been done according existing articles and researches. Researches shows opposite of the natural hazards and their effects on some structures and infrastructures, Natech events has not been paid under attention enough in Iran. While the variety of industrial plants and their structures in Iran is high, their existing condition and repairing and maintenance of them is not proper and according collected statistics in this article, the potential of NaTech events is also high in country. In the first step, to increase the preparedness for NaTech events, review of effective world experiences in this field is recommended. Recognition of past events and categorizing them and codification of data that should be included in safety reports and scenarios evaluation and considering the domino effects and review the recommendations in this field are parts of this step.
Dr. Habibollah Fasihi, Dr. Taher Parizadi,
Volume 10, Issue 4 (12-2023)
Volume 10, Issue 4 (12-2023)
Abstract
Urban planners consider historical fabric as the beating heart of cities. However, cities and specifically their historical fabrics are constantly under influence of natural and human-induced hazards. This study aimed to assess the vulnerability of Ferdowsi neighborhood as an example of Tehran’s historical fabric. The data was obtained from geographical information system (GIS) files and a survey, as well as historical contexts and documents were analyzed as part of this study. Ten municipal experts were also asked to provide a score of 1 to 5 for each of the 29 indicators compared to standard levels. The mean value of these scores was then used to evaluate the role of each parameter in the vulnerability of this neighborhood. Study findings indicate a high potential for the occurrence of natural and human-induced hazards in the study area. The abundance of unstable multistory buildings and derelict electricity and water networks, storage of flammables in warehouses, and lack of sewage network for half of the buildings were the most significant factors contributing to the vulnerability of this ancient fabric. Problems such as insecurity, drug abuse in public spaces, overcrowding and daytime congestion have also led to rapid relocation of neighborhood residents, who subsequently were replaced by commercial activities and warehouses. In conclusion, numerous problems are contributing to the vulnerability of historical fabric of this neighborhood and such problems are highly likely to be applied to other urban historical fabrics in Tehran.
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