Esmaeil Aliakbari; Mostafa Taleshi; Mohammadreza Karami; Kioumars Maleki
Abstract
Introduction
On average, an earthquake with the force of 6 magnitude of the Richter scale hits Iran every year and a 7.0 earthquake strikes the country every ten years. The fact that urban areas face serious damages due to these natural disasters makes it clear ...
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Introduction
On average, an earthquake with the force of 6 magnitude of the Richter scale hits Iran every year and a 7.0 earthquake strikes the country every ten years. The fact that urban areas face serious damages due to these natural disasters makes it clear that a crisis plan is quite necessary. City is a multi-layered structure consisting of closely related physical and non-physical components (functional, spatial, and social) with two levels of interaction among them. Providing a clear understanding of the consequences of hazards and evaluating vulnerable urban areas seem to be a necessary step toward decreased vulnerability to natural hazards. This will be definitely reached through policy making, making the right decisions and taking the right actions. The present study seeks to analyze zoning and vulnerability of Kermanshah metropolis in regard to possible earthquakes. Findings of the present study can be used to prepare an appropriate plan for the future of this city. The present study also explains physical, social and natural components, and uses a combination of these components to prepare different quantitative models and the necessary indicators (basic studies). It also attempts to provide methods of implementing these models and indicators (operational methods). And finally it seeks to prepare a hazard map to facilitate the identification of critical areas and impenetrable residential zones in Kermanshah metropolis, while determining optimal directions for future physical-spatial development of Kermanshah based on seismic risk zone. This is achieved through a new approach using Analytic hierarchy process.
Methodology
GIS and multi-criteria decision making methods are used in the present study for seismic zoning of natural, physical, social, and economic dimensions of Kermanshah. To reach this end, statistical, non-statistical and online sources were used and necessary maps were collected from relevant organizations and departments. In general, 1, 25000 topographic maps (AutoCAD Versions), Parcel maps of the 2016 census, land use maps showing the present situation (AutoCAD Versions), and etc. were used in the present study. Except for parcel map which was prepared in Shapefile (a well-known format prepared in ARCGIS software) and thus ready for GIS analysis, other layers were prepared in CAD format and had to be edited, revised, and then converted to Coverage format and Shapefile for final editing in GIS models. It is noteworthy that many of these maps were completed and edited by the authors. Then, maps required for each cluster were standardized using the classification method. Related weights and pairwise comparison matrix were defined for each cluster using scientific resources.
Results and Discussion
Due to the large number of sub-indicators used in the present study, each indicator was rated and graded separately. Results indicate that Kermanshah metropolitan area enjoys a desirable status regarding the economic indicator since69.6% of the city lies in the low vulnerability range of this indicator. Regarding the social indicator, the city is in an unfavorable status since56.6% of its area lies in a very high vulnerability range and only a small percentage of the city area (1.5%) lies in the low vulnerability range. Regarding the physical indicator, 57% of the city lies in the medium vulnerability range and 33.2% in the low vulnerability range. Regarding the natural indicator, 55.4% of the city lies in the medium vulnerability range, 36.5% in the high vulnerability range, 1.8% in the very high vulnerability range, and 6.3% in the low vulnerability range. The unfavorable status of the social indicator is due to the presence of areas facing high or very high levels of vulnerability. Findings of the economic indicator imply the distribution of an economic class with an average income in the city. Regarding the physical indicator, about 30% of the city area is covered by old vulnerable settlements constructed with unsustainable materials in direct contrast with urban planning rules. These areas require improvement, reconstruction, and renovation. Regarding the natural indicator, Kermanshah and its neighboring cities are built on earthquake fault lines. Dealing with this situation requires strengthening and modernization of old urban contexts, increasing permeability of arterial roads, development of non-physical spaces, making a greater use of empty spaces, and building new residential spaces (brownfield lands). Findings indicate the significant role of natural factors (including proximity to earthquake fault lines), physical factors (old contexts, inefficient materials, and etc.), and above all, lack of engineering supervision in the present constructions of the city. Land uses facing earthquake hazards in Kermanshah include residential (about 16% located in the very high vulnerability range), road network (about 15% located in the very high vulnerability), and emergency operation, military and medical centers. This will definitely jeopardize any rescue operation in possible future earthquakes.
Conclusion
Earthquake and its related devastating mechanism constitute a very complex process in which various factors play a role. These factors can reduce destructive effects of earthquakes on urban settlements. High population density, patterns of spatial distribution, vast man-made environment and different characteristics and conditions of its constructions have made analyzing the situation if not impossible (without computer and advanced software), quite difficult. The present study has analyzed different indicators and sub-indicators, and introduced inappropriate status of physical elements, inefficient road network, overcrowded and worn-out urban fabric in the city center, high density, and inappropriate distribution of open and green spaces in the city as the key factors resulting in increased vulnerability of land uses in the current zoning of the city. Due to the close relationship between damages of an earthquake and proximity to earthquake fault lines, development of a physical-spatial model in Kermanshah metropolis before the occurrence of future earthquakes seems necessary. Results indicate that in case rules and principles of urban planning are followed, endogenous and horizontal development of the city toward southern and northwestern direction seem to be logical. Furthermore, considering factors such as slope, slope direction and the east-west direction of faults, development of the city toward west or east is not recommended unless principles of urban planning and reinforcing is completely followed. Rough and rugged topography of the northern and northeastern parts of the city is also another obstacle to the physical development of the city in these directions. Therefore, physical-spatial development in the southern and southwestern direction, along with infill and endogenous development according to the potential of the city are recommended
Reza Borna
Abstract
Extended Abstract
Introduction
Dust is one of the atmospheric and climatic disasters whose occurrence causes environmental damages, respiratory and heart diseases, land and air traffic, tourist and agricultural problems, etc. Considering the great damages of this phenomenon and the possibility ...
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Extended Abstract
Introduction
Dust is one of the atmospheric and climatic disasters whose occurrence causes environmental damages, respiratory and heart diseases, land and air traffic, tourist and agricultural problems, etc. Considering the great damages of this phenomenon and the possibility of an increase in its occurrence in the coming years, the attention of the government and the implementation of appropriate solutions are essential in this regard. It is obvious that, before implementing the operational plans, the appropriate ways of dealing with this phenomenon can be found by having sufficient information and knowledge about it and the way and causes of its occurrence. To this end, it is essential to use the experiences and findings of other countries in this field in order to take a substantial step in this way by applying the right and principled methods. Some of the most important objectives of this research are to identify the factors affecting the dust phenomenon in Khuzestan province, to identify the methods of preventing the effects of dust in Khuzestan province, to use the AHP model for ranking the methods of preventing the effects of dust using the Analytic Hierarchy Process (AHP) in the study area.
Materials & Methods
The methodology of this research is analytical-descriptive, and the research is of applied type. In this research, the meteorological statistics of 12 meteorological synoptic stations of Khuzestan province were used during the period 0f 2001-2014 and, the map of the dispersion of dust storms in Khuzestan province was prepared. Considering the experts’ opinions, the major criteria which include the criteria of individual factors, extraterritorial factors and State factors were determined and then, the sub-criteria were determined for each criterion. After determining the criteria, the hierarchical graph of the criteria was created. Then, the criteria were compared with each other in the pairwise comparison matrices and the weight of each criterion relative to another one was assigned to that criterion in terms of the priority value. After the completion of the paired comparison matrices, the tree of criteria was created in EC2000 software, then, the applied scores were entered into the EC2000 software and the relative weight of each criterion resulted from the sum of the product of the significance of criteria and sub-criteria was obtained. The analysis of the inconsistency rate value is performed by EC2000 software during the pairwise comparison for each set.
Discussion & Results
Based on the yearly frequency of the occurrence of days with dust phenomenon during the 13 year statistical period (2001-2014), a total of 592.7 dusty days has been reported for the province of Khuzestan at the meteorological stations under study. The study of the data of all stations indicated that the highest frequency of dusty days was related to the Omidieh station with 125 days, then Dezful with 84.8 days and the lowest frequency was related to the Behbahan station with 22 days. The criteria studied in the dust phenomenon and the ranking of the methods for preventing its effects in Khuzestan, are diverse and complicated. Effective criteria in the ranking of the methods for preventing the effects of dust phenomenon are individual factors, extraterritorial factors and State factors that, each one of the main criteria has sub-criteria. In order to rank the methods of preventing the effects of dust phenomenon in Khuzestan province, observing the hygiene of houses and residential areas, keeping to personal hygiene (using masks and washing the mouth and nose), forming joint regional working groups (countries affected by dust), utilizing international facilities, adhering to regional and international commitments, Soil conservation programs, conservation and revival of wetlands and water resources, mulching, constructing windbreaks, sprinkling pebble, growing vegetation, providing medical equipment and informing people about the dangers of dust were selected, and using the Analytical Hierarchy Process ( AHP) model and Expert Choice software were evaluated.
Conclusions
The results of the calculations obtained from the application of Expert Choice software show that among the criteria studied, the State factors are the most influential index in ranking the methods of preventing the effects of dust phenomenon in Khuzestan, among other criteria. Considering the analysis of the sensitivity based on efficiency, the State factors criterion is more important than other criteria. In the analysis of sensitivity, individual factors, extraterritorial factors and State factors account for 29.7%, 16.3% and 54% of the total weight, respectively. Among the sub-criteria of individual factors, personal hygiene (using masks and washing the mouth and nose) with a weight of 0.750, accounts for the highest weight in ranking the methods of preventing the effects of dust phenomenon. Observing hygiene in houses and residential areas is at the next priority with a weight of 0.250. Among the sub-criteria of the extraterritorial factors, the formation of regional joint working groups of regional (countries affected by dust) with a weight of 0.540, adherence to the regional obligations has the highest role in the ranking of the methods of preventing the effects of dust phenomenon. The international sub-criterion with a weight of 0.297 and utilizing international facilities within the weight range of 0.163, have the subsequent priorities in the ranking of the methods of preventing the effects of dust phenomenon. Among the sub-criteria of the State factors, informing people about the dangers of dust with the weight of 0.263, soil conservation programs within the weight range of 0.155, providing medical equipment with the weight of 0.147, Conservation and revival of wetlands and water resources with the weight of 0.127 and creation of vegetation with the weight of 0.124 have the highest role in the methods of preventing the effects of dust phenomenon, respectively.
