Earthquake Vulnerability and Resilience Assessment of Razan city

Introduction
Rapid population growth, lack of resources and mismanagement have made natural hazards increasingly a major threat to human societies [1]. Among natural disasters, earthquakes are more frequent and are considered one of the most destructive natural hazards in the world and generally lead to many human and financial losses. Cities have complex and interdependent systems; Hence, they are more vulnerable to various threats, including earthquakes [2]. The main factors in increasing the damage during the earthquake are including increase in urban population, the location of the city next to active faults and also the lack of warning systems [3, 4 and 5], extensive construction, non-implementation of necessary standards in construction and city expansion without urban planning [6 and 7]. Vulnerability is the threshold of a society's response to disasters and environmental hazards [8]. Earthquake risk analysis, estimating its risks for different places and assessing the vulnerability of buildings, urban infrastructure at the time of the earthquake are among the initial measures that are implemented in urban planning [9]. Iran is one of the countries that has a very high vulnerability to earthquakes. Historical data show that every two to three years there is a significant earthquake in Iran. In twentieth century, in more than 20 earthquakes in Iran, between one hundred and forty thousand people have lost their lives, while many villages and towns have been destroyed. This led extensive economic damages. Hamedan province is also one of the provinces has a high seismic potential due to its location in the seismic zones of Iran, especially in the vicinity of active faults such as Avaj fault with a length of 167 km and northwest-southeast direction. The most important earthquake in this region occurred in 2002 with a magnitude of 6.5, which caused damage to rural areas of the city, which left cracks in the old city. Therefore, conducting studies on the vulnerability and resilience of the city and exploiting the results of these studies by land planners and decision makers in planning and preparing the city for hazardous events such as earthquakes can effectively and widely address the risks to decrease and increase urban resilience. In addition to the need to investigate the vulnerability of cities to environmental hazards such as earthquakes, the assessment of urban resilience is also a very high priority in urban planning, especially in the crisis management cycle.
Methodology
In this study, 15 sub-criteria and information layers were used to assess the vulnerability of Razan city, which include age of the building, structure of the building, number of floors, quality of the building ,law enforcement centers, width of roads, green space, seismic epicenter, fault, hazardous facilities, river, fire, and population density. The weight of each criteria and sub-criteria of the study area was determined using ANP method using super decision software. The selected layers were weighted and fuzzified using the weights obtained from ANP method in ArcGIS and then combined with each other to prepare a vulnerability map of Razan city. In order to assess the resilience of Razan city against earthquake risk, a questionnaire including 32 questions in social, economic, managerial, and institutional as well as environmental areas was designed. The opinion of city residents was evaluated by random sampling from all six neighborhoods.
Result and Discussion
Razan city vulnerability zoning shows most of Razan neighborhoods are close to 55% in high and very high-risk range, while only 24.2% of Razan neighborhoods are exposed to low and very low vulnerability. This indicates that city is vulnerable to earthquakes. These results confirm that Razan city is in a sensitive situation in terms of earthquake risk. In addition, more codified planning to reduce the vulnerability of this neighborhood seems to be necessary due to the dense population of Razan city, especially in the fifth neighborhood and its higher vulnerability than other urban areas. According to the research questions on measuring the resilience of Razan city, and according to the answers, all neighborhoods of Razan city are in a moderate situation in terms of resilience. It has a kind of downward average situation, except the neighborhood Six, which is moderately better tolerated than other neighborhoods. However, the third neighborhood has less resilience than other neighborhoods in the city and is also at a moderate level in terms of vulnerability. So, this neighborhood needs more attention in urban planning to reduce vulnerability and also increase resilience.
Conclusion
The location of Razan neighborhoods is exposed to earthquakes due to its proximity to several faults, especially Avaj fault. According to the geological characteristics, if the intensity and magnitude of the earthquake is high, the city is vulnerable. This research used a fuzzy hierarchical process, which presented a suitable classification of the vulnerability of the city to earthquake. In addition, the simultaneous assessment of the city's preparedness and resilience to earthquake risk, which can be extended to some other risks, was able to provide a proper assessment of the city's vulnerability and resilience to this event for decision makers in the field of management. The crisis of this city needs appropriate planning to reduce the effects of this devastating event in the city through well-planned planning and in the context of short-term and long-term plans. However, if all aspects of resilience are taken into account, the severity of these injuries can be reduced and, in other words, residents can be made more flexible in the face of crisis, especially the occurrence of a possible earthquake. According to the analysis of the questionnaire, the most important weaknesses of Razan city is insufficient knowledge by the residents of the city about the risk of earthquakes. Knowledge weaknesses in the relevant organizations about the necessary training in the field of crisis preparedness, and economic problems have reduced the resilience and vulnerability of Razan city to earthquakes.