عنوان مقاله [English]
Natural disasters are a phenomenon that neglect will cause irreparable damage. Extreme levels of flood danger were announced in at least three places. Baqershahr, as one of the important cities of Rey city, due to the location of several active faults and seasonal and permanent rivers around and inside it, as well as the existence of Behesht Zahra Grand High School, has a high vulnerability to natural and physical hazards, high population density. Also, the existence of the main fault of Rey Garmsar and rivers in the north of Tehran, the existence of aqueducts and high worn-out texture, is the main necessity and purpose of this realization. First, the research findings include the criteria of the natural index, which include sub-criteria of faults, slopes, rivers and aqueducts and physical criteria with sub-criteria of worn-out texture, urban thoroughfares, density of building units and special location, all of which are determined by urban planning experts. Urban and civil planning is measured in ANP network decision making software, pairwise comparison, and then interdependence between standard and sub-criteria. Finally, fuzzy maps are output in the software of Geographic Information Systems (GIS) software so that the map can be mapped. Operations of production and to assess and analyze the vulnerability of housing in Anj Be. With the produced maps, the danger points in the area of Baghershahr city are shown. Finally, it analyzes physical and natural indicators and how to manage the crisis in Baqershahr city. By obtaining the impact factor, the valued maps and zoning of critical factors are determined. The final result shows that the high-risk area in the west and southwest of Baqer Shahra is located in the path of fault, slope, worn texture and river. Maps are considered risk a.nd management zoning factors.
Iran with usually mountain topography, constructional land activity and more seismicity, different climate and geological conditions having major physical conditions for create rang to vast of landslide. The Iran realm in terms of special geographical situation (climatic and geomorphologic structure )to be exposed different natural accident such as earthquake, flood, tornado and drought. In the case of contraction accident from social-economical and natural endanger factors ,create great disaster to national economic structure of country.
From the beginning of twenty century so far occurred 20 earthquake as great as in Richter scale in Iran realm areas, that mean so in average each 7 years occur a great destructive earthquake crisis management is new topic in theme of confronting with unexpected accidents consequences and crisis originates from that. Crisis outbreak in data era that have characteristic like speed transformation and data communication with complicated data and in changing significant effects have on lead to outbreak of different damages and threat in different organization, national and transnational areas.
Problem that outbreak when crisis show is not being organization coordinated and sometimes people groups intervention in crisis control. So, elimination this problem and create a unity of procedure and when find more important that knowing Iran is a part of ten country of accident country. This lack of coordination in the crisis time caused outbreak complications that usually more of originate danger, persons and property in front of with problem and waste danger. So the searching method in management and command (unity crisis management) had vital important, by the way to suitable leadership and lead target. As the human take action for better life election and the best choice of factor for promote own life started planning but we should point out that human meet with the most common own life reality, mean environment crisis to face with a neglect and according to suffer human and economical damage and harm. With attention to unexpected of natural disaster and necessity of adopt to correct and speed decision and operation perform created main and theoretical foundation, a knowledge called a set of activity that do before, after and when occur crisis for reduce effects of danger and reduce vulnerability. This subject has special relation with urban planning and urban management and geography subject with use of element and roles of urban planning and making clear concept in this knowledge such as urban form, texture and structure, urban land use ,passage network and urban amenity can reduce more effect and consequence from natural disaster.
One of the important cities in Tehran state that in front of other cities with environmental crisis is Bagershahr city. In term of geographical situation, this city located in south of Tehran and from north and north east until south to be confined to Qamsar aqueduct and from east, south and north limited by Kahrizak fault and Rey, from east north limited by Behesht-e-zahra and finally in west with oil refinery that needs survey for urban physical development and run down texture in crisis time. So ,with attention to existence of physical and environmental disasters in Baghershahr. So ,this question to be mentioned that how can zoning of disaster showed set and control of danger factors?
In this research, the method of analysis is quality analysis (comparison) that known as descriptive analysis method. The goal of this research، at first step is gain parameter of vulnerability amount assessment against natural disaster with study precedent and refer to scientific and reliable references and then in second step determine main priority in relation with urban housing vulnerability in Baghershaher city with questionnaire in 100 number of experts that work in housing and town planning organization at unexpected events staff and also municipality. In third step, determine distinction each criteria with use of ANP model and Super Decision software for comparison both. Especial weight to be achieved from ANP model to use place layers. In other step ,this weight applied in Arcgis software and to each layers at criteria and to be accomplish with putting together layers. Then the result final map in raster form in GIS. Interaction and feedback between criteria is bilateral .Evolution is in both comparison on 9to1 from (odd number) and on priority one criteria on other criteria.
Discussion and Results:
The first and most dangers event in Baghershaher is earthquake. In Baghershaher, the main threatening faults are Kahrizak ,Rey and Garmsar faults ,with attention to gained weight ,both comparison in ANP model assigned more priority to own between another faults index because city occupied from three side by faults, the duty of crisis management in this section is equipped west south section that have most danger and then reinforcement housing units from west side to centre and then east ,earthquake is less danger. In the city as much as is close to 0 fault the earthquake danger is more and as much as is close to 255 ,danger is less.
The gradient of case study region is variable from 0 to 20. Indeed gradient in region is important factor that in occurring time of landslide danger can to be effective. In ANP model the gradient priority is between another three priority index , and their index is 0/11100 in construction and population density and desirable region gradient is closer, so vulnerability of crisis factor is less. Crisis management with study to be able prevention from flood, supplying and subsided.
One of the disaster in the region is permanent and seasonal rivers. Baghershaher city limited by water channel and Kan river that overflow from west of Tehran and move to west of the Baghershaher. Indeed the river show that area of the this region exposed to flood danger and so in during of tectonical movement in front with rote displacement of this river and stream. In ANP model nearness and distance priority to river between other index is second priority and index is 0/21014 and nevertheless area that near to river have high danger. Indeed crisis management can have flood index and minimum radius for permitted and unauthorized constructing with use of map that until prevent before and doing needing actions.
The other natural disaster in Baghershaher is aqueduct in the east of the city. Aqueduct have too landslide danger and too digging danger in housing that should correct canalize and separation from this subject is close to oil and gas refinery. So, there is pollution danger of aqueduct. The gained weight of this danger in ANP model is 0/09750.The region that is close to aqueduct valuation is low and dangerous and region that is far have valuation high and less danger. Crisis management should be for specified before readiness ,periodically visit and to arm aqueduct to concrete.
One of the main element in crisis management is necessity of passage network, tributary and main access. The passage network of Baghershaher is composed of old sector and narrow allay that is a main problem for services. Indeed, passage network because of region old texture have not favorable situation and high way communication network is a little favorable and in north section have better quality. Network passage weight in ANP model assigned 0/03169.As much as closer to this access passage is less vulnerability and action after earthquake will be favorable. Existence of especial lands and open space is favorable characteristic of the region and is considered of main basis in settling, but in Baghershaher installation and amenity in oil refinery is one of the most pollution and dangerous place that height of area in the east is most dangerous. The weight in ANP model with attention to other index assigned 0/08331 that from vulnerability have relatively important hazard.
Run down texture is one of the places that can be more vulnerability and if would be more in the city to be counted one of the crisis in that region. Unfortunately Baghershaher city have a lot of run down texture that the rate of this area is enormously. In other criteria ,run down texture gained in the city assigned 0/08539 valuation. The duty of crisis management is empowerment of this texture and equip forces in this texture. The effect of run down texture and their destruction and vulnerability to other texture show that most effect in on the city centre.
Parts area and units density is very important so, units between 120-200 to high to be consider for main density criteria that density with exact identification and valuation can determine amount of damage and management. Indeed degree of density damage known as a main damage centers and it is not basis of damage but is part of vulnerability. In ANP model the gained weight in this criteria is 0/04071 and ratio to other criteria assigned less priority.
In theoretical foundation and background of research show more important and necessity of damage subject from natural factor in world and especially in Iran. In recent years comment that to be mentioned show some flexibility to crisis management in cities. In this theme, rapid grow of urbanization and unbroken process of urban in developing country, necessary to forgive improvement of management and urban planning. In this regard ,manager and urban planner follow election set of suitable policy and coordinated in strategic regards that not only can lead available resource effectively to response in urban increasing needs but also reduce being risky some of environmental accidents. In this research, survey factors for crisis management improvement in general and gained for each physical and natural factor in Baghershaher city as fuzzy maps with danger radius for survey model compatibility with use of expert opinions in three groups civil (structure) urban planning and geography and urban planning in weight lifting to criteria in ANP model and evaluation their opinions. In this section, can wrap up that with crisis management effects in Baghershaher submit application output that can said important factors in Baghershaher and very much vulnerability degree indeed is natural index that in fault factor the weight is obtained 0.34and gradient factor with weight 0.11 and aqueduct factor with weight 0.97 and river factor in this index with weight0.21created problems in north and west and centre sections of Baghershaher and from physical index, run down texture with weight 0.085 and then building units density with weight 0.04 ,urban passages with 0.03 and final factor in this index especial place , oil refinery with 0.02 in centre and east and finally whole city being undesirable situation but natural index is extraordinary danger. For survey accuracy and correct of results in gathering data need to use consideration and region vulnerability analyzes in with using criteria so detail in region with several visits that to be accomplished case study region and from several city section visit for data accuracy and all of the case lead to executive maps and determine danger situation in the city that in time of crisis occurrence management system with use of maps do rapid and suitable response.