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Hassan Afrakhteh,
Volume 2, Issue 4 (1-2016)
Volume 2, Issue 4 (1-2016)
Abstract
The City-region of Tehran is encountered with various environmental problems, including traffic, air pollution, lack of drinking water and green space, physical texture conflict, flood and earthquake. Capital accumulation has considerable role in shaping spaces which can create and intensify environmental disaster in special socio-economic situation. The second cycle is the conversion of capital to fixed and long-term assets with the aim of further benefits, which in fact produces two types of artificially environment during this process namely the built environment for production, and the built environment for consumption.
The third cycle is aiming to connect science to production and increase production capacity by investment in science and technology. When production of surplus value reduced in the first cycle, surplus value of second cycle increases through speculation and real estate transaction (real estate capital). Therefore, the owners of the lands and buildings are encouraged in production, trade and supply of these type assets.
In the courtiers that are legally and administratively encounter with tax receipt problems, urban lands ownership is deposited to market system without any control, hosing transaction continues without any limitation, situation is moving forward to personal vested interests, asset value rises rather than production value, the price of land and construction increase severely. In the above mentioned condition, beneficiaries attempt convert the natural resources including park, mountain, river privacy and road privacy to marketable commodity and legally or quasi legally seize them. Therefore, unreasonable construction and population density increases and city-region will encounter with environmental disasters.
The main objective of this research is to understand the underlying factors of capital accumulation through construction and its impacts on createion and intensification of environmental disasters in the Tehran city-region.
Five different regions of Tehran were selected for data collection. "Q-methodology" was used for gathering and analyzing data. The society of communication or people whom the study sought to identify their mentality towards the research topic, were 25 experts selected through purposive sampling. To set the concourse of communication, a combination of primary (experts commented in an interview) and secondary (sources of credit) sources have been used and 34 statements have been developed. After sorting the data for analysis, SPSS software data matrix is formed. Factor analysis, as main method of analyzing Q data matrix has been used based on Q logical methodology.
The results of Q analysis depicted four viewpoints with variance of 95.911 percent on the underlying cause of capital accumulation through construction and its contribution on increasing risk of natural hazards in Tehran city-region.
The first viewpoint has devoted 52.800 percent of total variances and can be titled as" Function of real estate transaction and Non-productive economic domination".
The second viewpoint which has received 18.914 percent of total variances is accordance with "commodification of land and housing". The third viewpoint is" management and monitoring of the city-region space" with 15.163 percent of total variances. The fourth viewpoints under the title of" monitoring and control of natural resources" has assigned 9.034 percent of total variances.
As result of these processes, land and housing business have weakened society's productive capacity by extensive land use change in the urban peripheral area's due to its huge and quick profit. The above process accompany with selling excess density policy created a powerful political and economic stratum which harmed city sustainable development. The mountainous area of north, north east and west of Tehran, have annexed to metropolis as a result of above mentioned regulation and may gardens have converted to construction by different gropes and institutions.
Q method analysis depicted that the Tehran City-Region has converted from use value to exchange value. It means that values of the city including work, security, education, leisure and welfare have been lost in favor of exchange value. In other words, the city has been converted to a commodity for exchange and selling in pursuit of profit, rising cost of urban land, building and housing. Consequently, the city-region construction site is extended to the river beds, steep slops and surrounding natural environment. This in turn is leading to rapid land use change and violation of environmental and spatial rules and regulations and intensification of environmental hazards.
Jalal Karami , Aminah Mohamadi, Mohammad Sharifikia,
Volume 3, Issue 2 (5-2016)
Volume 3, Issue 2 (5-2016)
Abstract
Resilience are concepts that are finding increasing currency in several fields of research as well as in various policy and practitioner communities engaged in global environmental change science, climate change, sustainability science, disaster risk-reduction and famine interventions (Vogel, et.al, 2007). Where the risk is a probability of damage, injury, liability, loss, or any other negative occurrence that is caused by external or internal vulnerabilities, and that may be avoided through preemptive action (Benson, et.al, 2004). Among natural disasters, earthquakes, due to the unpredictable nature of these events, are one of the most destructive. Iran is one of the most earthquake-prone countries in the world that its cities most affected by this phenomenon. Among the cities of Iran, Tehran, as the country's first metropolis, due to dense population, poor physical development, structural density, and lack of standards, is potentially facing a serious threat. The purpose of this study is to investigate the spatial flexibility of Tehran over the region 12 after the earthquake incidence.
The present study is dealt with the data preparing and analysis using geospatial methods. The several geospatial data such as Peak Ground Acceleration (AGA) map, urban structure, infrastructure and population collected from Tehran Disaster Management Center were provided and analysis based some GIS known algorithms. In other to urban spatial resilience zonation the AHP (analytical Hierarchy Process) was implemented to generation risk map. Finally OWA (Ordered Weighted Average) method was implemented in order to Production spatial flexibility map of earthquake incidence over the District 12 of Tehran. AHP model uses of priorities straight experts, but OWA provides of control the level of compensation and risk-taking in a decision. Using the conceptual of fuzzy quantifier with OWA makes the qualitative data analysis enter to decision.
According to flexibility of the final map with fuzzy operator (All) equivalent to the operator MIN, the worst result Was obtained and resulting the highest risk and lowest flexibility respectively (Districts Nos. 2,12,7,8 and 11).By taking all the criteria of a criterion without compensation by other criteria as "non-risk" is obtained .
Map obtained with fuzzy operator (Half) has the high potential to provide suitable options, because in addition to integration criteria the importance of each parameter based on the weight given to the criteria are considered. In this map Districts Nos.2.6 and 8 (Baharestan, Emamzadeyahya and Sanglajedarkhangah) respectively were most Risk to earthquakes and therefore less flexibility to the earthquake. The map obtained with the fuzzy operator "Atleast one" is equivalent to MAX operator districts Nos. 2,12,7 and 8 (Baharestan ,DarvazehGhar of Shush,Abshardardar and Sanglajedarkhangah) respectively were most Risk to earthquakes and therefore less flexibility to the earthquake.
The fuzzy conceptual map quantifier showed that districts Nos. 2 and 12 (Baharestan and DarvazehGhar of Shush) were most vulnerable and therefore less flexibility to the earthquake as final results.
Mojtaba Rafiean, Hadi Rezai Rad,
Volume 4, Issue 3 (9-2017)
Volume 4, Issue 3 (9-2017)
Abstract
The simplest definition of urbanization is that urbanization is the process of becoming urban. Urban climate is defined by specific climate conditions which differ from surrounding rural areas. Urban areas, for example, have higher temperatures than surrounding rural areas and weaker winds. Land Surface Temperature is an important phenomenon in global climate change. As the green house gases in the atmosphere increases, the LST will also increase. Energy and water exchanges at the biosphere–atmosphere interface have major influences on the Earth's weather and climate. Numerical models ranging from local to global scales must represent and predict effects of surface fluxes. The urban thermal environment is influenced by the physical characteristics of the land surface and by human socioeconomic activities. The thermal environment can be considered to be the most important indicator for representing the urban environment. Vegetation is another important component of the urban ecosystem that has been the subject of much basic and applied research. Urban vegetation influences the physical environment of cities through selective absorption and reflection of incident radiation and regulation of latent and sensible heat exchange Satellite-borne instruments can provide quantitative physical data at high spatial or temporal resolutions. Visible and near-infrared remote sensing systems have been used extensively to classify phenomena such as city growth, land use /cover changes, vegetation index and population statistics. Finally, we propose a model applying non-parametric regression to estimate future urban climate patterns using predicted Normalized Difference Vegetation Index and Heat Island Intensity.
I conducted all spatial analysis in the UTM Zone 39 Northern Hemisphere projection. The fundamental procedure I used for evaluating change in land surface temperature was to relative temperature for both images, so that the values are temperature difference between the coldest and hottest areas in Tehran metropolitan. subtracting these images from each other results in relative temperature change from 2003 to 2015. Landsat satellite data were used to extract land use/land cover information and their changes for the abovementioned cities. Land surface temperature was retrieved from Landsat thermal images. The relationship between land surface temperature and landuse /land-cover classes, as well as the normalized vegetation index (NDVI) was analyzed.
In this study, LST for Tehran metropolitan was derived using SW algorithm with the use of Landsat 8 Optical Land Imager (OLI) of 30 m resolution and Thermal Infrared Sensor (TIR) data of 100 m resolution. SW algorithm needs spectral radiance and emissivity of two TIR bands as input for deriving LST. The spectral radiance was estimated using TIR bands 10 and 11. Emissivity was derived with the help of land cover threshold technique for which OLI bands 2, 3, 4 and 5 were used. The output revealed that LST was high in the barren regions whereas it was low in the hilly regions because of vegetative cover. As the SW algorithm uses both the TIR bands (10 and 11) and OLI bands 2, 3, 4 and 5, the LST generated using them were more reliable and accurate. NDVI negatively affected LST and Urban Heat Island in vegetation areas in 2003 and 2015 in Tehran metropolitan. This analysis provides an effective tool in evaluating the environmental influences of zoning in urban ecosystems with remote sensing and geographical information systems. This method exhibits a promising performance in UHI forecast. The predicted LST confirms that urban growth has severely influenced UHI pattern through expanding the hot area. Our study confirmed that LST prediction performance is strongly depended on the resolution.
The results reveal that the urban LST is affected mainly by the land surface characteristics and has a close relation to the abundance of vegetation greenness. The spatial distance from the UHI centre is another important factor influencing the LST in some areas. The methodology presented in this paper can be broadly applied in other metropolitans which exhibit a similar dynamic growth. Our findings can represent a useful tool for policy makers and the community awareness of environmental assessment by providing a scientific basis for sustainable urban planning and management. This provides an effective tool in evaluating the vegetation greenness of different zoning in urban ecosystems with remote sensing and geographical information systems. From the perspective of land use planning and urban management, it is recommend that planners and policy makers should pay serious attention to future land use policies that maintain a relevant proportion of public space, green areas, and land surface physical characteristics.
I conducted all spatial analysis in the UTM Zone 39 Northern Hemisphere projection. The fundamental procedure I used for evaluating change in land surface temperature was to relative temperature for both images, so that the values are temperature difference between the coldest and hottest areas in Tehran metropolitan. subtracting these images from each other results in relative temperature change from 2003 to 2015. Landsat satellite data were used to extract land use/land cover information and their changes for the abovementioned cities. Land surface temperature was retrieved from Landsat thermal images. The relationship between land surface temperature and landuse /land-cover classes, as well as the normalized vegetation index (NDVI) was analyzed.
In this study, LST for Tehran metropolitan was derived using SW algorithm with the use of Landsat 8 Optical Land Imager (OLI) of 30 m resolution and Thermal Infrared Sensor (TIR) data of 100 m resolution. SW algorithm needs spectral radiance and emissivity of two TIR bands as input for deriving LST. The spectral radiance was estimated using TIR bands 10 and 11. Emissivity was derived with the help of land cover threshold technique for which OLI bands 2, 3, 4 and 5 were used. The output revealed that LST was high in the barren regions whereas it was low in the hilly regions because of vegetative cover. As the SW algorithm uses both the TIR bands (10 and 11) and OLI bands 2, 3, 4 and 5, the LST generated using them were more reliable and accurate. NDVI negatively affected LST and Urban Heat Island in vegetation areas in 2003 and 2015 in Tehran metropolitan. This analysis provides an effective tool in evaluating the environmental influences of zoning in urban ecosystems with remote sensing and geographical information systems. This method exhibits a promising performance in UHI forecast. The predicted LST confirms that urban growth has severely influenced UHI pattern through expanding the hot area. Our study confirmed that LST prediction performance is strongly depended on the resolution.
The results reveal that the urban LST is affected mainly by the land surface characteristics and has a close relation to the abundance of vegetation greenness. The spatial distance from the UHI centre is another important factor influencing the LST in some areas. The methodology presented in this paper can be broadly applied in other metropolitans which exhibit a similar dynamic growth. Our findings can represent a useful tool for policy makers and the community awareness of environmental assessment by providing a scientific basis for sustainable urban planning and management. This provides an effective tool in evaluating the vegetation greenness of different zoning in urban ecosystems with remote sensing and geographical information systems. From the perspective of land use planning and urban management, it is recommend that planners and policy makers should pay serious attention to future land use policies that maintain a relevant proportion of public space, green areas, and land surface physical characteristics.
Farzaneh Sasanpour, Navid Ahangari, Sadegh Hajinejad,
Volume 4, Issue 3 (9-2017)
Volume 4, Issue 3 (9-2017)
Abstract
International studies show that the damages caused by natural hazards is essential that special attention to natural hazards in urban societies of the world, especially in urban areas of developing countries. In many of these communities needed new ways to deal with these challenges. This method should provide sufficient knowledge to identify the nature of problems and the identification of individual characteristics, socio-economic, physical, environmental and management, would in effect do the "Back to Balance" against natural hazards. This feature Back to Balance the same resiliency. The term resilience has a very long history and its use goes back at least a century BC. According to the different interpretations of the concept of resilience, this term is rooted in the traditions of various disciplines such as law, engineering, ecological and social sciences. Today, the concept of resilience has entered the field of planning with different orientations (social, economic, physical, and administrative, etc.).Although it still focuses more attention on environmental issues and a large part of its exploration dedicated to managing the environmental hazards such as earthquakes, floods, hurricanes and global warming. Tehran, as a result of political and economic influence, special conditions to deal with the crisis in terms of the influence of natural disasters and crisis management in terms of organizational structure and legal. In this respect, residential and urban areas of 12 with characteristic their history can be acute against the imbalances caused by natural hazards and create a crisis in urban life. Therefore, the present study has been prepared for the purpose of stability analysis flexibility in District 12 of Tehran metropolitan city.
This is of cognitive research that has been done for analytical and descriptive. All data is obtained in the manner of library and field. The library of available resources and work conducted the form of a questionnaire survey. Questionnaires have been used of type Likert spectrum (numerous, high, high, somewhat, relatively low, low and very low), and its completion is done by fieldwork. Statistical population has problems of urban planning experts, among them 80 people were interviewed for targeted samples. Resiliency that includes four dimensions (economic, social, ecological, environmental and institutional). Was approved the validity of the index by 7 experts manage urban planning problems. For measuring reliability coefficient is calculated Cronbach's alpha equal to 0/79. For data analysis, the use of statistical analysis such as frequency, maximum and minimum, average and standard deviations, T-Test one sample test and Friedman nonparametric test
The results of the indicators of urban resiliency against natural hazards suggests that economic indicators 73/24 Average been determined and relatively low level, ie below the average level. Results of the test showed one sample T-Test is an indicator of economic status of urban resilience against natural hazards of poor utility. As well as the social, ecological, environmental and institutional (organizational) urban resilience against natural hazards associated with poor utility. Finally the 12 metropolitan Tehran metropolitan areautility resilience against natural hazards with respect to all dimensions were too weak. Friedman test results on the scoreboard indicators showed that the index of environmental sustainability (20/33) related to the ecology and environment in the first rank the importance of urban resilience and adaptability Index System (10/11) related to next institutional (organizational) is set as the least significant indicator. Also, significant chi-square statistic is calculated at a rate of 09/67 in three degrees of freedom at the level of 0.000. So, with a probability of 99% can be said that there is a significant difference between the performance rating of 80 specialist urban resilience dimensions (economic, social, ecological, environmental and organizational) against natural hazards, and not the distribution of the same rank.
This research been prepared with the aim of assessing the scale of urban resilience against natural hazards in District 12 of Tehran Metropolis. Results showed that social, environmental and institutional ecology and urban resilience against natural hazards associated with poor desirability. According to this result, it is concluded that the region as a whole is resilient against natural hazards. In this direction, the resilience approach guidance to managers and practitioners use of flexible decisions and concerted policy for urban management. Build resilience in this area to support programmes should invest in organizing access to both external and existing resources in a fair manner, with a coordinated governance structure, and to facilitate social solidarity and support as part of disaster response. The findings also stress the importance of taking an ecological approach to studying resilience to disasters. Many factors from individual, community, and societal levels seem to be important in shaping resilience perceptions of natural hazards survivors. Understanding this evidence will help to validate and further develop indicators of resilience. Our findings point out that, despite existing pre-disaster vulnerabilities, resilience can be fostered following disasters if community members perceive availability of aid and support and mobilize resources Hence, psychosocial support programmes should invest in organizing access to both external and existing resources in a fair manner, with a coordinated governance structure, and to facilitate social solidarity and support as part of disaster response. The findings also stress the importance of taking an ecological approach to studying resilience to disasters. Many factors from individual, community, and societal levels seem to be important in shaping resilience perceptions of natural hazards survivors. Future research should conduct multiple levels of analysis with an all-hazards perspective to reveal how they can be integrated to increase adaptive capacities. Future research should focus on the process of capacity building through informing action to better prepare for disasters. Finally, this research tells us that due to the resiliency of the city will be able to have knowledge of all relevant indicators in the resiliency and reduce the adverse effects of these risks in urban communities
This is of cognitive research that has been done for analytical and descriptive. All data is obtained in the manner of library and field. The library of available resources and work conducted the form of a questionnaire survey. Questionnaires have been used of type Likert spectrum (numerous, high, high, somewhat, relatively low, low and very low), and its completion is done by fieldwork. Statistical population has problems of urban planning experts, among them 80 people were interviewed for targeted samples. Resiliency that includes four dimensions (economic, social, ecological, environmental and institutional). Was approved the validity of the index by 7 experts manage urban planning problems. For measuring reliability coefficient is calculated Cronbach's alpha equal to 0/79. For data analysis, the use of statistical analysis such as frequency, maximum and minimum, average and standard deviations, T-Test one sample test and Friedman nonparametric test
The results of the indicators of urban resiliency against natural hazards suggests that economic indicators 73/24 Average been determined and relatively low level, ie below the average level. Results of the test showed one sample T-Test is an indicator of economic status of urban resilience against natural hazards of poor utility. As well as the social, ecological, environmental and institutional (organizational) urban resilience against natural hazards associated with poor utility. Finally the 12 metropolitan Tehran metropolitan areautility resilience against natural hazards with respect to all dimensions were too weak. Friedman test results on the scoreboard indicators showed that the index of environmental sustainability (20/33) related to the ecology and environment in the first rank the importance of urban resilience and adaptability Index System (10/11) related to next institutional (organizational) is set as the least significant indicator. Also, significant chi-square statistic is calculated at a rate of 09/67 in three degrees of freedom at the level of 0.000. So, with a probability of 99% can be said that there is a significant difference between the performance rating of 80 specialist urban resilience dimensions (economic, social, ecological, environmental and organizational) against natural hazards, and not the distribution of the same rank.
This research been prepared with the aim of assessing the scale of urban resilience against natural hazards in District 12 of Tehran Metropolis. Results showed that social, environmental and institutional ecology and urban resilience against natural hazards associated with poor desirability. According to this result, it is concluded that the region as a whole is resilient against natural hazards. In this direction, the resilience approach guidance to managers and practitioners use of flexible decisions and concerted policy for urban management. Build resilience in this area to support programmes should invest in organizing access to both external and existing resources in a fair manner, with a coordinated governance structure, and to facilitate social solidarity and support as part of disaster response. The findings also stress the importance of taking an ecological approach to studying resilience to disasters. Many factors from individual, community, and societal levels seem to be important in shaping resilience perceptions of natural hazards survivors. Understanding this evidence will help to validate and further develop indicators of resilience. Our findings point out that, despite existing pre-disaster vulnerabilities, resilience can be fostered following disasters if community members perceive availability of aid and support and mobilize resources Hence, psychosocial support programmes should invest in organizing access to both external and existing resources in a fair manner, with a coordinated governance structure, and to facilitate social solidarity and support as part of disaster response. The findings also stress the importance of taking an ecological approach to studying resilience to disasters. Many factors from individual, community, and societal levels seem to be important in shaping resilience perceptions of natural hazards survivors. Future research should conduct multiple levels of analysis with an all-hazards perspective to reveal how they can be integrated to increase adaptive capacities. Future research should focus on the process of capacity building through informing action to better prepare for disasters. Finally, this research tells us that due to the resiliency of the city will be able to have knowledge of all relevant indicators in the resiliency and reduce the adverse effects of these risks in urban communities
Jamileh Tavakolinia, Alireza Mehrabi, Ehsan Allahyari,
Volume 6, Issue 2 (9-2019)
Volume 6, Issue 2 (9-2019)
Abstract
Today, air strike on installations and urban areas, is normal. As such, vulnerability assessment cities and provide the right solution for harm reduction is essential. The purpose of this investigation was to identify factors causing damage in the district of twenty in Tehran. The research method is descriptive-analytic and Data collection is library and field. Data analysis is based on using Ahp and GIS. Results show, In the district twenty , There are three zones vulnerable. Including, The old Central, The high-density Dolatabad and sizdah aban neighborhood. These zones are 34 percent of the land. The reason of it is Poor physical structure. Statistical Society is Twenty district in Tehran. Sample size is 384 people of residents of the district. Because, in this area there are strategic factors, is An important part of the tehran city. in the end, are provided The right solution of Reducing vulnerability.
Dr Abolfazl Meshkini, Mr Ali Mohammad Mansourzadeh, Mr Zeynab Shahrokhy Far, ,
Volume 6, Issue 3 (9-2019)
Volume 6, Issue 3 (9-2019)
Abstract
Identifying spatial patterns in vulnerability involves a comprehensive look at vulnerable points. And provides analytical power to the authorities. Therefore, it is necessary to recognize patterns of vulnerability so as to minimize the amount of damage to them in the event of a crisis. The city of Tehran, as the political and administrative center of the country, is faced with a variety of risks due to demographic burden and physical development. In this research, we tried to analyze the spatial distribution pattern of urban vulnerability to natural hazards in social and physical dimensions in Tehran's 7th region. The method of this descriptive-analytic study and the model used for trigonometric fuzzy logic. The results indicate that: According to the z score, the positive values are 1.96 up, which form the clusters of hot spots in the southeastern region of the arena; It is a sign of more vulnerability in these areas. Also, negative values of 1.96 and less, which are statistically significant and blue, have formed cold spots, And it is interpreted that low vulnerability zones are clustered in space and are mainly located in the northwest. Therefore, the lower the color range in the red and blue areas was less statistically significant to the point where this positive net worth is 1.65 that in this situation, the spatial behavior of the vulnerability is considered to be non-significant in terms of hot or cold clusters with high and low values and spatial autocorrelation that the map is also displayed in yellow.
Aydin Moradi, Somaye Emadodin, Saleh Arekhi, Khalil Rezaei,
Volume 7, Issue 1 (5-2020)
Volume 7, Issue 1 (5-2020)
Abstract
Khabat Derafshi,
Volume 7, Issue 3 (11-2020)
Volume 7, Issue 3 (11-2020)
Abstract
In this study, the risk map as an index to define the said complexity was prepared in 5 categories of risk by combination of Tehran metropolis flood hazard and vulnerability maps. To analyze the risk varieties, the hydrological catchments of Tehran were extracted by Arc Hydro model and 12 catchments were selected. Using land use, roads network, and the percentage of residential floor area, bridges, altitude, slope and drainage density variables, the flood hazard map was calculated. Dilapidated urban blocks, population density, land use, bridges, slope and drainage density layers were used as variables which affecting the flood vulnerability. Covariance index was applied for matched variables and considering the locational coherence between the values of them. Based on the new raster layers, flood risk variability in Tehran metropolis as well as in each of the catchments were analyzed using stepwise regression model. Explanation of locational changes of risk between the catchments needs to calculate the weighted average risk and the independent variables in 12 catchments that obtained by zonal statistics. Based on these average values the factor analysis used to determine the varifactors or main components of the variability in flood risk between the catchments. Finally, fractal geometry models (perimeter-area and cumulative number-area) were used to demonstrate the chaos of the flood risk value in 5 categories of risk. According to the flood hazard zoning map of Tehran metropolitan area, the extent of high hazard zone is 129.6 square kilometers. High risk zone covers 28.6% of Tehranchr('39')s area, indicating that most of the citychr('39')s extents (174.4 square kilometers) are located in the high flood risk zone. After that, the moderate hazard zone is 28.5% of the city area. Very low zones with 3.53% of the total area are the smallest zones in the city, which are only 21.5 square kilometers. Overall, 78.3 percent of the total area of the city is located in the moderate to very high zones of flood hazard, reflecting Tehranchr('39')s challenge to flooding. The vulnerability map defines that 138 km2 of the Tehran city area is located in high and very high zones of the flood vulnerability. According to Tehran metropolitan flood risk zoning map, 163.1 km2 of Tehran city area is located in high risk zone which has the highest rate among flood risk categories in Tehran metropolis (26.9%).
Alireza Kazemi, Behnod Barmayehvar,
Volume 7, Issue 4 (2-2021)
Volume 7, Issue 4 (2-2021)
Abstract
Due to the insecurity of the construction industry, the purpose of this study is to evaluate safety management and investigate its impact on reducing accidents of sites in urban construction projects in the south of Tehran. Due to the nature and type of research, the present study is descriptive-correlational and practical research. The statistical population in this study is supervising engineers working in the field of urban construction in the south of Tehran (15, 16, 17, 18, 19, and 20 areas). Therefore, according to the latest statistical report published by the Tehran Engineering System Organization (5000 people) and based on the Morgan table, 351 acceptable answer sheets were collected.
In this research, data collection and information were performed using the library-documentary method and field method (with the help of observation tools, interviews, and especially questionnaires) and through a combined method (quantitative-qualitative) with quantitative nature and focus as well as survey strategy. Also in this research, in addition to utilizing the capacities of qualitative content analysis, the methods of quantitative analysis include descriptive statistics including frequency, average, and standard deviation, as well as inferential statistics including Kolmogorov-Smirnov, Friedman, Pearson, T-tests and regression analysis by SPSS 24 software, was used. Questionnaire questions were validated by reviewing previous research, consulting with experts, and validating with factor analysis and reliability using Cronbach's alpha method.
The results show that among the three effective factors in improving safety management and reducing site accidents in urban construction projects in the south of Tehran, the factors of “use of protective equipment”, “compilation of responsibilities” and “risk management” with averages of 4.0864, 4.0741, and 3.9812 are ranked the first, second, and the third rank, respectively. Besides, the average part of various site accidents is 4.0000.
According to the results of the research, from the total types of site accidents of “injuries to people due to non-use of personal protective equipment”, “damage to urban underground facilities during nailing operation”, “life and financial losses due to standard and unsafe construction site equipment”, “occurrence of silent death in workers' rooms due to unsafe gas appliances and lack of proper ventilation, “collapse of structural parts during welding”, “fall of workers, materials, and equipment from a height”, and “collapse of the walls of the pit and adjacent plaques due to lack of standard and standard excavation” are ranked first to seventh with an average of 5.7692, 4.8148, 3.8490, 3.7322, 3.7236, 3.1282, and 2.9829, respectively.
According to previous research, the “policy (compilation of responsibilities)” factor has the first impact on the safety of the construction industry, but in a case where the field of research is limited to construction projects and urban constructions (personalization) in which in such projects safety management is not generally systematic in the site, the prioritization between the factors affecting the safety management of the site has changed and the “policy (compilation of responsibilities)” factor is transferred to the second rank and the “use of protective equipment” factor is placed in the first rank. Therefore, builders and employers, and that project supervisors must be required to closely monitor this carefully formulate safety responsibilities in construction workshops.
Considering that, the factor of “non-use of personal protective equipment” is in the first place as the cause of site accidents and has already been ranked in the fifth place of safety hazards, so it can be concluded that since the last decade, the factor of “non-use of personal protective equipment” has risen from the fifth to the first rank. Therefore, it is necessary to pay more attention to the use of protective equipment in construction sites in Tehran, project supervisors should be stricter in this regard, and engineering organizations and municipalities should enact stricter rules and regulations.
According to the supervising engineers active in the field of research, “damage to urban underground facilities during nailing method” is in the second place in the classification of common types of site accidents in the field of urban construction of Tehran and nailing method for stabilization of deep urban ditches causes legal problems to enter the privacy of adjacent license plaques and obtain notarized consent from the owners of adjacent license plaques, in addition to the risk of damaging underground urban facilities and causing heavy damage to the project and it is necessary to use other modern methods of deep pit stabilization, including the “Top-Down” method.
In this study, “human and financial losses due to non-standard construction site equipment” is classified in the third rank of site accidents. Therefore, the municipalities and organizations of the engineering system must make the issuance of technical inspection certificates for site equipment mandatory and if the employer and the constructor do not provide the necessary documents in this regard or to prevent the continuation of executive operations.
Because accidents due to non-observance of safety issues in construction sites continue to occur for various reasons, it is necessary to establish stricter rules and regulations regarding non-compliance with safety issues in construction sites in the field of urban construction and the use of a safety officer in the site with relevant educational and professional backgrounds and qualifications is mandatory for all construction sites.
The results of this study show that increasing attention and accuracy in the areas of responsibility compilation, risk management, and use of protective equipment improves safety management and reduces accidents in construction sites in the field of urban construction of south of Tehran.
In this research, data collection and information were performed using the library-documentary method and field method (with the help of observation tools, interviews, and especially questionnaires) and through a combined method (quantitative-qualitative) with quantitative nature and focus as well as survey strategy. Also in this research, in addition to utilizing the capacities of qualitative content analysis, the methods of quantitative analysis include descriptive statistics including frequency, average, and standard deviation, as well as inferential statistics including Kolmogorov-Smirnov, Friedman, Pearson, T-tests and regression analysis by SPSS 24 software, was used. Questionnaire questions were validated by reviewing previous research, consulting with experts, and validating with factor analysis and reliability using Cronbach's alpha method.
The results show that among the three effective factors in improving safety management and reducing site accidents in urban construction projects in the south of Tehran, the factors of “use of protective equipment”, “compilation of responsibilities” and “risk management” with averages of 4.0864, 4.0741, and 3.9812 are ranked the first, second, and the third rank, respectively. Besides, the average part of various site accidents is 4.0000.
According to the results of the research, from the total types of site accidents of “injuries to people due to non-use of personal protective equipment”, “damage to urban underground facilities during nailing operation”, “life and financial losses due to standard and unsafe construction site equipment”, “occurrence of silent death in workers' rooms due to unsafe gas appliances and lack of proper ventilation, “collapse of structural parts during welding”, “fall of workers, materials, and equipment from a height”, and “collapse of the walls of the pit and adjacent plaques due to lack of standard and standard excavation” are ranked first to seventh with an average of 5.7692, 4.8148, 3.8490, 3.7322, 3.7236, 3.1282, and 2.9829, respectively.
According to previous research, the “policy (compilation of responsibilities)” factor has the first impact on the safety of the construction industry, but in a case where the field of research is limited to construction projects and urban constructions (personalization) in which in such projects safety management is not generally systematic in the site, the prioritization between the factors affecting the safety management of the site has changed and the “policy (compilation of responsibilities)” factor is transferred to the second rank and the “use of protective equipment” factor is placed in the first rank. Therefore, builders and employers, and that project supervisors must be required to closely monitor this carefully formulate safety responsibilities in construction workshops.
Considering that, the factor of “non-use of personal protective equipment” is in the first place as the cause of site accidents and has already been ranked in the fifth place of safety hazards, so it can be concluded that since the last decade, the factor of “non-use of personal protective equipment” has risen from the fifth to the first rank. Therefore, it is necessary to pay more attention to the use of protective equipment in construction sites in Tehran, project supervisors should be stricter in this regard, and engineering organizations and municipalities should enact stricter rules and regulations.
According to the supervising engineers active in the field of research, “damage to urban underground facilities during nailing method” is in the second place in the classification of common types of site accidents in the field of urban construction of Tehran and nailing method for stabilization of deep urban ditches causes legal problems to enter the privacy of adjacent license plaques and obtain notarized consent from the owners of adjacent license plaques, in addition to the risk of damaging underground urban facilities and causing heavy damage to the project and it is necessary to use other modern methods of deep pit stabilization, including the “Top-Down” method.
In this study, “human and financial losses due to non-standard construction site equipment” is classified in the third rank of site accidents. Therefore, the municipalities and organizations of the engineering system must make the issuance of technical inspection certificates for site equipment mandatory and if the employer and the constructor do not provide the necessary documents in this regard or to prevent the continuation of executive operations.
Because accidents due to non-observance of safety issues in construction sites continue to occur for various reasons, it is necessary to establish stricter rules and regulations regarding non-compliance with safety issues in construction sites in the field of urban construction and the use of a safety officer in the site with relevant educational and professional backgrounds and qualifications is mandatory for all construction sites.
The results of this study show that increasing attention and accuracy in the areas of responsibility compilation, risk management, and use of protective equipment improves safety management and reduces accidents in construction sites in the field of urban construction of south of Tehran.
Mohhamad Soleimani Mehranjani, Ali Movahhed, Ahmad Zanganeh, Zeinab Ahmadi,
Volume 8, Issue 1 (5-2021)
Volume 8, Issue 1 (5-2021)
Abstract
Explain the Processes of Modernization on the Spatial Mismatch in Urban Neighborhoods
(The case of, Region 4 of Tehran Municipality)
Modernization processes and modern urban planning policies have had significant effects and consequences on the spatial transforms of cities in the world and Iran. Among that processes, we can mention the growing gap between social groups and urban spaces based on a number of contexts and mechanisms that, from the late 1960s onwards, have been conceptualized and measured experimentally under what is called the “spatial mismatch hypothesis”. The basic methodology for estimating the state of spatial mismatch in cities or urban regions is based on the logic of “spatial segregation” between social groups and land uses simultaneously; Because based on the spatial mismatch hypothesis, it is not possible to explain the segregation mechanisms between social groups in the city without considering its relation with segregation mechanisms in urban spaces or land uses, and vice versa. Based on such methodological logic, the present paper has assessed the state of spatial (mis)match in Region 4 of Tehran Municipality. The method of data collection was in the form of libraries and data available in the Statistics Center (General Census of Population and Housing in 2016 and at the level of demographic blocks of the region), Road and Urban Development Organization, Municipality of Region 4. Variables used to analyze the spatial mismatch in the region
The level of education, employment in study abroad and inside the country, employment and unemployment status, level of housing infrastructure, type of housing ownership, changes in land use pattern and the amount of daily commutes in the study area.
Findings obtained based on the defined variables and techniques used in Segragation Analyzer and ArcGIS software show that the state of spatial mismatch in this urban region (like many other cases in cities around the world) is high, but its intensity is higher in terms of job and literacy of social groups in relation to the state of activity and residential land uses. Relying on such findings, some strategies and policies have been proposed to reduce the state of spatial mismatch in Region 4, and to contribute to a more even and equitable distribution of development in this region and hence reduce poverty among the lower classes.
Keyword:
Urban modernization, spatial mismatch hypothesis, socio-spatial segregation, Region 4 of Tehran Municipality
Mahmoud Ahmadi, Zahra Alibakhshi,
Volume 8, Issue 2 (9-2021)
Volume 8, Issue 2 (9-2021)
Abstract
Evaluation of hot spots changes in Tehran city and satellite based on land use and its role in urban heat hazards
Expanded abstract
Problem statement:
Urbanization and human activities affect the urban climate and clearly affect the air temperature close to the surface. In Tehran and its satellite, factors such as climatic region, season, time of day and wind regimes, topography, urban environments, population density, residents' activity, vegetation structure and urban physical form play an important role in the formation of urban heat islands. The purpose of this research is to determine the type of spatial distribution of heat islands of Tehran metropolis and satellite cities using land use and land cover. Replacing natural land cover with impervious surfaces due to urban development has negative environmental, social and economic impacts, in addition to beneficial aspects. Most of the albedo belong to the built areas and the bare land and the smallest of the Albedo belong to the aquatic areas and vegetation. In this research, the hypothesis is whether the suburbs may have higher temperatures than urban areas depending on the type of land use? In fact, it is examined the spatial distribution of the heat island of Tehran and its satellites, in which the use of land and land cover are analyzed as a factor contributing to the creation, intensification or reduction of the thermal island.
Methodology:
Extraction and preparation of imagery data through the Landsat 7 Satellite ETM + sensor over the years 2001-2015 and selection of June as the hottest month of the study area. These images were extracted from Route 164 and Row 35 of the USGS. An assessment was carried out through the accuracy of ground surface temperature data by Landsat satellite images and obtained temperatures from the weather stations in the area based on the Taylor diagram. In order to investigate the spatial structure of the cells obtained in each map, each containing surface temperature and heat island extraction, it used the methods of world spatial autocorrelation (high and low clustering, spatial correlation) and local (Cluster and Outlier analysis, hot spot analysis). The high and low clustering statistics show how the concentration of high or low values in the region. In the next step, the results of analysis of Anselin Local Moran and hot spots were compared in map format. Hot spots were analyzed in all studied regions and in all 7 cities. The area of hot spots was investigated over the course of 15 years and the results were presented in table and diagram form.
Land use was surveyed for every 7 county. In the last section were studied, the relationship between hot spots in each city and type and land use changes over 15 years.
Surface spatial analysis of the surface temperature of the area showed that the cells follow a cluster pattern and their trend towards clustering. Any kind of land cover and land use will create special features in a place that can be increased or decreased with a specific microclimate.
Explaining and results:
After selecting the years 2001, 2005, 2010, and 2015 as the sample and survey of the temperature of each land use in that year, it was determined that artifact, pasture, bare lands, forest, aquatic areas, agriculture and green spaces were respectively have the highest to the lowest temperature in the area. On the other hand, in the area of heat island in a region are Rabat Karim, Ray, Islamshahr, Tehran, Shahriar, Karaj and Shemiranat, respectively.
In spite of the reduction of aquatic areas and even bare lands, because of the large impact of green space or agricultural land was reduced the extent of heat islands during the statistical period, and on the contrary, the reduction of green space and agricultural land in places where even their forest areas have grown, has increased the levels of heat islands. This suggests that the dispersion and extent of green spaces has a more effective role in reducing the heat island compared with the creation of limited forest and planted surfaces in one place. Hence, in Tehran despite the significant growth of artifacts, due to the increasing growth of green space, the heat islands has been reduced compare with the Ray, Robatkarim and Islamshahr cities, which are exactly on its suburbs.
Keywords: Heat Island, hot spots, land use, Tehran, satellite cities.
Ms Mahsa Sepasian, Dr. Bohloul Alijani, Dr. Mohammad Salighe, Dr. Mehry Akbary,
Volume 8, Issue 4 (1-2021)
Volume 8, Issue 4 (1-2021)
Abstract
Tehran metropolitan with its large population, daily migrant workforce and many students, needs to planning and designing watch/warning system to reduce the climatic problems for human health.for this purpose, we need to study the climate accurately and Since the factors affecting the climate of warm and cold periods in Iran are different, in this study , the meteorological variables of Tehran warm period (May to September 2002) turned into 4 components in Temporal Synoptic Index (TSI) using PCA Method and using P-Array and Varimax rotation.By the scores of components for each day, the clustering method (in ward method) were used and, the warm days of the year was divided into two cluster named favorable and oppressive airmasses. The average maximum air temperature that is more effective in mortality, was 36.13 ° C. Days with temperatures above 34 ° C, less pressure, mild winds , dryness and more sunshine resulted in more adverse weather conditions, which resulted in a 34% increasing in mortality compare with favorable weather. The total number of deaths from cardiovascular disease during the study period was 154046 that about 67%of deaths have been simultaneous with oppressive airmass.The epidemiological study of mortality also confirms the results of previous research in this area and shows that the incidence of mortality is higher in older people as well as in men. It is clear that not all mortality can be attributed to the effects of climate, but results show that change in climatic conditions will affect on mortality and also for study the effect of climatic hazards on human health, it is better that we study the effect of all variables together on humans.
Nader Shohani, Lotfali Kozegar Kalj, Sajad Darabi, Said Yousefi Babadi,
Volume 9, Issue 1 (5-2022)
Volume 9, Issue 1 (5-2022)
Abstract
Pandemic Covid-19 (Corona); Tehran's resilience against it
Nader Shohani; Assistant Professor, Department of Geography and Urban Planning, Payame Noor University. Tehran Iran
Lotfali College Potter; Associate Professor, Department of Geography and Urban Planning, Shahid Beheshti University, Tehran, Iran
Sajjad Darabi; PhD Student, Department of Geography and Urban Planning, Shahid Beheshti University, Tehran, Iran
Saeed Yousefi Babadi; PhD student, Department of Geography and Urban Planning, Shahid Beheshti University, Tehran, Iran
Abstract
One of the dangers that has caused cities to face a serious crisis is the outbreak of Covid-19 disease. The corona pandemic has taken cities out of their normal routine. Therefore, cities seek to return to their past conditions and urban resilience as soon as possible. Research Method In this descriptive-analytical study, using field survey, four economic, social, managerial-institutional and infrastructural dimensions in the form of 29 items have examined the resilience of Tehran against Corona pandemic. In research, support and advocacy for affected businesses, insurance coverage, support for affected manufacturing sectors, are in the most unfavorable situation. The results obtained from the final table of Vikor technique show that the economic index with a score of 1 is the most important component of resilience against coronavirus, which is lower than other components of resilience. After that, the managerial-institutional component with a score of 0.94 and the infrastructure component with a score of 0.92 in the next ranks are the most important components of Tehran's resilience against coronavirus. The results show that the metropolis of Tehran is not in a favorable position in relation to the corona virus and is not resilient to selected indicators and the economic index has the most impact and the social index has the least impact on the resilience of Tehran.
Keywords: Urban Resilience, Covid 19, Pandemic, Tehran
Pandemic Covid-19 (Corona);
Tehran's resilience against it
Mr Seyed Kamyar Mortazavi-Asl, Dr. Navidsaeidirezvani Saeidirezvani, Dr. Mahmud Rezaei,
Volume 9, Issue 1 (5-2022)
Volume 9, Issue 1 (5-2022)
Abstract
Evaluation of the effect of particulate matter and vegetation on the formation of heat and cold islands in Tehran
Seyed Kamyar Mortazavi Asl: PhD Student in Urban Planning, Islamic Azad University, UAE
Dr. Navid Saeedi Rezvani: Assistant Professor, Department of Urban Planning, Faculty of Architecture and Urban Planning, Islamic Azad University, Qazvin, Iran
Dr. Mahmud Rezaei: Associate Professor, Department of Urban Planning, Faculty of Architecture and Urban Planning, Islamic Azad University, Tehran, Iran
Abstract:
Global warming and the heat islands of cities are one of the biggest challenges in the world today. Cold islands is a word that stands in front of heat islands and refers to areas of the city that have lower temperatures than the surrounding areas. In this study, in order to investigate the factors affecting the formation of cool and heat islands of the city, it was first obtained by using Landsat image processing and using the single-channel surface temperature algorithm. Then to investigate the parameters affecting the land surface temperature changes; Criteria for changes in particulate matter and changes in vegetation were considered. The NDVI index was used for vegetation and the algorithm proposed by Saraswat et al. was used for the amount of particulate matter. According to the results, the highest-ranking neighborhood for heat islands were in Bustan, Shahid Bagheri township and the airport, respectively, and the lowest amount of cool islands were in Baharan, Niavaran and Darband, respectively. Pearson coefficient obtained from the relationship between surface temperature and vegetation was -21.29%, which indicates the inverse relationship between temperature and vegetation, as well as the amount of vegetation index in hot and cold regions. Regarding the relationship between land surface temperature and air pollution, the correlation between these two parameters was equal to 19.31% and comparing the pollution index in areas with cold and warm islands showed that there is a significant relationship between reducing air pollutants and cold islands but the opposite is not true.
Keywords: Cool Islands, Tehran, LST, Air Pollution
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.
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.
Javad Sadidi, Hassan Ahmadi, . Ramin Rezae Shahabi, Amir Pishva, Omid Kheyri, Godratallah Nooraie,
Volume 10, Issue 3 (9-2023)
Volume 10, Issue 3 (9-2023)
Abstract
The pervasiveness of the concept of vulnerability in various dimensions has led to the emergence of the theory of vulnerability in the spatial sciences. According to the theory of vulnerability, in any given space, there is a coefficient of vulnerability, while the levels and amplitude of safety are not evenly distributed on the surface of that space. Residential use is one of the most important and main uses in the urban land use system, and safety management and attention to its defense requirements are very important due to the high population density in large cities. The present study is in the field of assessing the vulnerability of residential uses against external threats with a passive urban defense approach in District 10 of Tehran, which was conducted in the form of spatial studies and by implementing an analytical model in three steps. First, the principles and requirements of passive defense were identified and classified into three groups of structural, demographic and spatial parameters, and using the questionnaire and expert survey tools, the priorities of passive defense principles in relation to residential spaces were determined. Then, based on the network analysis process, the weight of each criterion was determined and the weight of the ANP model was applied to the spatial layers of the region in ArcGIS software. The results of the model showed that in terms of structural indicators, more than 78% of residential units in the region are in the group of structures with high vulnerability and in terms of demographic indicators, in 88% of residential units in case of external threats, the level of vulnerability is high. In terms of spatial indicators, more than 92% of residential spaces are adjacent to several incompatible uses and have the highest vulnerability. In general, the results of overlapping layers showed that more than 86% of residential units in the area are located in vulnerable zones and the vulnerability of residential units in these zones is very high.
Hossein Hataminejad, Alireza Sadeghi,
Volume 10, Issue 3 (9-2023)
Volume 10, Issue 3 (9-2023)
Abstract
Measuring urban resilience can help develop appropriate strategies and policies for cities facing unexpected shocks and their consequences. Since urban resilience is a complex concept and difficult to operationalize, developing a technique or method to actualize this concept is a major milestone in understanding the factors and interactions that help create and maintain resilience. Tehran's metropolis has a high concentration of industries, government organizations, services, and facilities, which makes its management very complicated when a natural disaster occurs. Previous conditions or inherent socio-economic characteristics show that Tehran is not immune from flood forces. In fact, it is important to measure resilience against urban disasters for areas located on rivers in Tehran due to its inherent characteristics and spatial-temporal changes of floods in the region. This research focuses on measuring the resilience of the areas located on the rivers of Tehran. The measurement approach is based on creating a composite index based on six dimensions of social, economic, institutional, infrastructure, social capital, and environmental resilience against floods. This research has been done by developing a mixed multi-criteria decision-making method. The AHP model has been used for prioritizing the selected indicators and the TOPSIS model has been used to rank the areas located on the rivers of Tehran city based on their resilience levels. The results show that region 22 is the most resilient region, while regions 4, 5, and 14 have the lowest resilience levels. The findings of this research can help urban planning organizations such as Tehran Research Planning Center to integrate disaster resilience in urban planning and change from reactive plans to preventive urban adaptive strategies such as risk-sensitive urban land use planning.
Tajdin Karami, Ali Shamaei, Fateme Mohebi,
Volume 10, Issue 4 (12-2023)
Volume 10, Issue 4 (12-2023)
Abstract
Abstract
Ecological resilience is a concept that implies the reversibility of ecological structures and functions against the shocks experienced. The northern zone of Tehran, as the most important ecological support of this city, has undergone many land-use changes in recent decades. The present study has analyzed the role of land-use change in the ecological resilience of green infrastructure (as one of the pillars of ecological structure) in District 1 of Tehran Municipality. This study is an applied one in terms of purpose and is considered a descriptive-analytical one in terms of the method used. In this study Landsat satellite data (1976-2021) were used to detect the changes of interest, and landscape metrics were used to analyze the ecological resilience conditions. Based on the results of this study period, the Number of Patches (NP) has significantly increased and the Class Area (CA) has decreased during the period covered by this study. These changes indicate the fragmentation process and loss of structural cohesion of the green patches. The measurement results for the connectivity metrics (ENN and GYRATE) also showed a small connectivity between the green patches in the area. In addition, the results for CONTAG (Contagion Landscape metrics) measure indicated that, due to low connectivity, the transmission rate is low. Therefore, it can be said that the green infrastructure of the region has lost its structural cohesion in the face of land-use change, and as a result, the expected ecological functions and services have also failed. According to the results, the green infrastructure of the study area is vulnerable to land-use changes and their ecological resilience has been significantly reduced.
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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