عنوان مقاله [English]
Since the beginning of the creation of man on earth, natural disasters have always been impressed the living conditions and human settlements. During the twentieth century, more than 1,100 destructive earthquakes occurred in different parts of the Earth. In these earthquakes, more than 1,500,000 people was died.
Based on studies, the majority of deaths occurred due to lack of proper planning and ineffective management of the city at before of the earthquake. Review, explanation and analysis of the crisis such as an earthquake could have great significance in the issues of spatial analysis and reducing the risk. The Earthquake Vulnerability Analysis of citizens is one of the most effective Proceedings to reduce the effects of earthquakes. The location of services equipment, including hospitals, police stations, fire station, the Red Crescent and others, have a major role in disaster management and vulnerability reduction coefficient of citizens. For example, in the BAM earthquake, more than 80 percent of the city was destroyed and about 50,000 people have died. While in the earthquake occurred within 4 days after the bam earthquake in San Robles, California, which has the same scale of the bam earthquake, only two people died. Iran has about 1% of the world population, While the death of earthquake is due to situation in alp- Himalayas belt is about 6 percent of all deaths in the world.
Vulnerability evaluation of citizens is the first step in the crisis management of earthquake. GORGAN city as the study area of this research is due to, crossing the main fault of the Alborz from the city center, considerable area of historical and ancient texture, fragile and soft soil structure, the high slope of the land in parts of the city, the population growth and increasing of floor due to environmental and agricultural Restriction, heavy traffic on some of the axes at many hours of the day, high contrast height between the highest and lowest parts of the city and high age of service building, Virtually have the high potential risk from earthquakes.
This paper due to target, is practical and developmental, due to doing method is descriptive and analytical and due to information gathering method is documental and surveying and User defined weight is used for weighting method. Weighting method is FAHP and to perform the targets of research 9 criterion including: the vulnerability coefficient of citizens on the basis of the distribution of fire stations, hospitals and police centers, access to the city network, age of buildings, slope, type and age of building materials, access to free and empty spaces and obstruction of network have been used.
Result and Discussion
According to the results, significant parts of the City in southern limit and northern and eastern rim, will be a great challenge in field of access to the fire station service. In addition, the central areas of the city, that mainly in accordance with the old and ancient textures are also in the field of access to the fire service will experience problems. Revision to the arrangement of existing stations or adding some station to the existing stations can greatly reduce the vulnerability of citizens. The vast majority of citizens that living in the southern and northern of the city have difficult to access to the hospital. Central and eastern areas of the city are in next level. Despite the establishment of the hospital in the northern areas of the southern part of the city due to the small width of street against to their height, practically falling the debris of building disrupt the vehicle to access network. After running the algorithm, in different parts of the city no matching the free space and population structure has been observed. Lack of space allocation to some of the blocks and high cost of transport vector for moving the population from residential area to free spaces confirmed this claim. 1006 city block with a population equal to 221.847 people, haven’t secure access to the free spaces.
On the other hand, the average distance between the population and server spaces is equal to 939 meters, this distance for moving the vulnerable population that caused by the earthquake will be unreasonable. in the city of GORGAN, 13.31% of the buildings made from materials such as mud and brick. This subject confirms the vulnerability of this class in times of crisis.
The highest percentage of materials class with a frequency of 44.48% Has allocated to cement and bricks class and mostly related to one or two floor buildings with age of 20 to 30 years. after the earthquake crisis, 18.35 percent of urban roads will be blocked completely. 18.24% of the roads will also experience an approximate obstruction and 63.4% of the road will be retained the operation of commuter vehicles. Given the current structure of the urban network, likely more than 35 percent of the Gorgan cities road, during the earthquake lose the necessary performance to move the vehicle. This could cause a lack of efficiency of the machine service process and in some parts of city such as ancient texture, gorganjadid, janbazan and dokhaniyat districts will be touch intensively.
According to the distribution of free public spaces, actually 65% of GORGAN population haven’t any necessary access to free spaces and temporary housing. lack of these spaces, especially in the congested areas is more than the other parts.
According to the results, 33% of the population with 120675 people, are located in low to very low risk areas. 44% of the population with population of 160900 people are located in area with moderate risk and 23% of the population, with population of 84107 people are located in high and very high areas.
Vulnerability, Earthquake, Metaheuristic Algorithm, FAHP, GIS