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Ali Eshghei, Hossein Nazmfar, Ata Gafari,
Volume 7, Issue 2 (8-2020)
Volume 7, Issue 2 (8-2020)
Abstract
Spatial analysis physical resiliency City Earthquake Model Condorcet Case study: ten districts of the region one of Tehran Abstract Earthquake as one of the most devastating and destructive natural hazards; especially in developing countries, it has been a long time ago With the collapse of buildings and urban infrastructure, Imports a lot of damage to property and assets in urban areas and around them. In response to this, international organizations' strategies to mitigate disasters have made their societies resilient to natural disasters. And considers it within the framework of the Higgo for the years 2005-2015. In fact, the goal of this approach is to reduce the vulnerability of cities and to strengthen citizens' abilities to deal with the dangers of threats such as natural disasters. Considering that the area of a Tehran city due to its proximity to faults such as Mashaa fault, North Tehran fault Also, the effects of faults in and around the region such as Niavaran fault, Mahmoodieh fault and Darabad fault (Banamieh) are located in a region with a high seismic hazard. Assessment of resilience of the region to earthquake risk and resilience of the region In order to reduce the risks of earthquakes in this area is very important. Accordingly, the present study was conducted with the aim of assessing the resilience situation of the 10th district of Tehran municipality district against earthquake. The method of this research is descriptive-analytical with a purposeful purpose. The research area of the 10th Region is a municipality of Tehran. The raw data used by the Tehran Municipality Information Technology Organization has been obtained. To determine the relative importance of each component used in research According to experts from the Urban Planning Area, the Network Analysis Process (ANP) has been used in the form of Super Decisions software. Then, to rank 10 areas of a Tehran municipality district against earthquake, Multi-criteria decision making models (MCDMs) including TOPSIS, VIKOR, HAW and SAW models have been used. Considering that different methods have been used to rank the areas Different results have been achieved, to overcome the contradictions between the various ratings of the regions in each of the models, and a single result has been used to rank the areas of the congregation's integrated model. Finally, in order to speak, the results of the model used in the ArcGIS environment were mapped. In this research, for the spatial analysis of the resilience of the 10 district areas of a Tehran municipality from the results four models (TOPSIS, VIKOR, HAW and SAW) were used. Based on the results of the TOPSIS technique, areas 8, 3 and 2 of resilience are large, areas 7 and 4 of the moderate resilience, Areas 5, 1, 6 and 10 have low resilience and area 9 has very little resilience against the earthquake. Based on the results of the VIKOR model, areas 3 and 4 of the resilience, regions 2, 7, 5, 9, 8, 6 and 10 of the moderate resilience Medium and area one have low resilience against earthquake. Based on the results of the HAW model, area 3 of the high resilience, regions 2, 7, 8 and 4 of the moderate resilience and areas 10, 1, 6 and 9 are of low resilience. In this model, no area has been found to be very resilient. Based on the results of the SAW model, regions 3, 2, 8, and 7 are in the range of many resiliences, regions 5 and 4 in the moderate resilience range, Area 9 is in the low resilience range and areas 10, 6 and 1 are in the low resilience range against earthquakes. In this study, we evaluated the resilience situation in the districts of Tehran municipality district in an earthquake Multi-criteria decision-making methods including TOPSIS, VIKOR, HAW and SAW were used, Then a CONDORCET integrated model was used to achieve a single result of these analyzes. The results of the Canadian model, which is the result of a combination of the final results of the models (Tapis, VIKOR, HAW and SAW), show that Areas 2, 4, 5, and 3 are of high resilience, areas 7, 8 and 1 of the moderate resilience, 10 and 6 of the resilience, and area 9 of the resilience is very low against earthquakes. Which should be prioritized in future plans. Although it is possible to assess the vulnerability of urban areas by using different models and mapping them in the region's resilience to the earthquake crisis, a significant part of post-crisis casualties fell but this will not be achieved until the authorities are seriously determined. Keywords: Resilience, Earthquake, Multi-criteria Decision Making Methods, Tehran Municipality Area
Fateme Emadoddin, Dr Ali Ahmadabadi, Seyed Morovat Eftekhari, Masumeh Asadi Gandomani,
Volume 10, Issue 3 (9-2023)
Volume 10, Issue 3 (9-2023)
Abstract
Introduction: Land subsidence is one of the environmental hazards that threatens most countries today, including the majority of Iran's plains (Ranjabr and Jafari, 2010). Damages caused by subsidence can be direct or indirect. Infrastructural effects are direct and indirect effects of subsidence, but economic, social and environmental effects are indirect effects of subsidence (Bucx, et al., 2015). The environmental effects of subsidence are related to other effects of subsidence, including the infrastructural, economic and social effects of subsidence. The southwest plain of Tehran is considered one of the most important plains of Iran due to its large areas of residential, agricultural and industrial lands from various aspects, especially economic, political and social. The subsidence of the Tehran plain was first noticed by the measurements of the country's mapping organization in the 1370s. Since 2004, the responsibility of investigating this phenomenon in the plains of Tehran was entrusted to the Organization of Geology and Mineral Explorations of the country. Although several researches have been done in the field of subsidence factors, amount and zoning. In the field of estimation of subsidence and changes in water level, spatial correlation of subsidence with changes in water level and estimation of vulnerability due to subsidence according to the density of population, settlements and facilities in the southwestern plain of Tehran has not been done.
Methodology: In the current research, we will analyze and estimate the spatial regression of the subsidence phenomenon by InSAR technique with water level changes from 2005 to 2017, as well as the environmental effects of subsidence in the southwest plain of Tehran by using Quadratic analysis method (O’Sullivan and Unwin, 2010). The criteria map of the current research is overlapped using the ANP method (Ahmedabadi and Ghasemi, 2015) weighting and finally with the SAW method (Emaduddin et al., 2014) in the Arc GIS 10.8 software, and the vulnerability map due to land subsidence in the study area is prepared.
Results: The average subsidence in 12 years is about 9.9 cm per year. Average subsidence has occurred in four main zones. Maximum and minimum subsidence have been observed in B (near the Sabashahr) and D (in east of plain) zones respectively. The results of the interpolation of the depth of the underground water in the study area indicate that the general trend of increasing the depth from the south (10 meter) to the north (more than 90 meter) of the plain. The results of spatial correlation showed that there is a significant direct relationship between the spatial layer of the average subsidence rate of Tehran Plain and the spatial data of the underground water level, and the R value is equal to 0.61. The distribution map of the underground water depth of the study area in the form of Quadrat analysis shows that in the main part of the plain, the depth of underground water is at an average level. The general trend of changes in the level of underground water is decreasing from northwest to southeast and is in 5 levels. The distribution of the networks shows that the rivers have three linear trends from north and northwest to south; their dispersion is mostly in the center of the study area. The flood rate is higher in the central plain networks. In study area, there are important arterial roads such as Tehran-Qom highway, Tehran-Saveh highway and Tehran Azadegan highway. The southern and northeastern areas of the study area are urban settlements such as Islamshahr, the 18th and 19th districts of Tehran Municipality and other residential areas such as Sabashahr. The major part of the region has fertile soil and the occurrence of subsidence can have negative effects on the fertility and texture of the soil in the study area. The results of vulnerability analysis due to subsidence show that there are 5 vulnerability classes in the study area including very low, low, medium, high and very high.
Conclusions: All in all most of the study areas (central, northern and western networks) are in medium, high and very high vulnerability. About 14,600 hectares of the study area are in medium vulnerability. Which is continuous from the west to the east of the study area. Most of the urban infrastructures are moderately vulnerable to subsidence. About 17,000 hectares of the southwestern plain of Tehran are very vulnerable. That more than half of the area of this area is covered by settlements and urban infrastructures. Therefore, the phenomenon of subsidence causes irreparable damage to the settlements and infrastructures in the southwest plain.
Methodology: In the current research, we will analyze and estimate the spatial regression of the subsidence phenomenon by InSAR technique with water level changes from 2005 to 2017, as well as the environmental effects of subsidence in the southwest plain of Tehran by using Quadratic analysis method (O’Sullivan and Unwin, 2010). The criteria map of the current research is overlapped using the ANP method (Ahmedabadi and Ghasemi, 2015) weighting and finally with the SAW method (Emaduddin et al., 2014) in the Arc GIS 10.8 software, and the vulnerability map due to land subsidence in the study area is prepared.
Results: The average subsidence in 12 years is about 9.9 cm per year. Average subsidence has occurred in four main zones. Maximum and minimum subsidence have been observed in B (near the Sabashahr) and D (in east of plain) zones respectively. The results of the interpolation of the depth of the underground water in the study area indicate that the general trend of increasing the depth from the south (10 meter) to the north (more than 90 meter) of the plain. The results of spatial correlation showed that there is a significant direct relationship between the spatial layer of the average subsidence rate of Tehran Plain and the spatial data of the underground water level, and the R value is equal to 0.61. The distribution map of the underground water depth of the study area in the form of Quadrat analysis shows that in the main part of the plain, the depth of underground water is at an average level. The general trend of changes in the level of underground water is decreasing from northwest to southeast and is in 5 levels. The distribution of the networks shows that the rivers have three linear trends from north and northwest to south; their dispersion is mostly in the center of the study area. The flood rate is higher in the central plain networks. In study area, there are important arterial roads such as Tehran-Qom highway, Tehran-Saveh highway and Tehran Azadegan highway. The southern and northeastern areas of the study area are urban settlements such as Islamshahr, the 18th and 19th districts of Tehran Municipality and other residential areas such as Sabashahr. The major part of the region has fertile soil and the occurrence of subsidence can have negative effects on the fertility and texture of the soil in the study area. The results of vulnerability analysis due to subsidence show that there are 5 vulnerability classes in the study area including very low, low, medium, high and very high.
Conclusions: All in all most of the study areas (central, northern and western networks) are in medium, high and very high vulnerability. About 14,600 hectares of the study area are in medium vulnerability. Which is continuous from the west to the east of the study area. Most of the urban infrastructures are moderately vulnerable to subsidence. About 17,000 hectares of the southwestern plain of Tehran are very vulnerable. That more than half of the area of this area is covered by settlements and urban infrastructures. Therefore, the phenomenon of subsidence causes irreparable damage to the settlements and infrastructures in the southwest plain.
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