Resilience Assessment of Physical Urban Areas against Earthquake: The Case of old neighborhoods in Bushehr)

Introduction Communities around the world are increasingly affected by disasters caused by natural hazards, conflicts and humanitarian emergencies or man created disasters. These disasters often happen in unexpected forms, intensity and places which, in practice, makes any prevention impossible. Many people around the world lose their life because of the natural disasters, while the survivors will remember these bitter experiences. In this sense, our country is among the ten vulnerable countries in the world. During the past 90 years, 12,000 people in the country have lost their lives as a result of disasters and the highest number of casualties (76 percent) has been caused by earthquake. The old areas of the city are vulnerable places. On the one hand, in terms of environmental hazards, specially earthquake, and functional, environmental, social and economic abnormalities on the other hand; and requires detailed, comprehensive, informed and planned intervention to organize them.Increasing the Resilience of cities against natural disasters, especially earthquake, is effective in reducing losses and in the recovery period of the communities. Physical Resilience is one of the influencing factors in the resilience of communities, through which influencing physical and geographical features of societies can be evaluated during disasters. Bushehr is a seismic area, because it is located in the Zagros region, on the edge of Zagros; and also Zagros fault passes Bushehr and it is near to Borazjan. There are some faults which are active and sometimes cause damage. There are some areas in the old regions of Bushehr with high vulnerability against natural disasters (particularly earthquake) which lead to increased vulnerability of their residents when catastrophe occurs. Low quality of the buildings leads to little Resilience against natural disasters, which increases the vulnerability of these areas. In fact this question is posed: how are the physical sub-criteria in old areas of Bushehr? As the old areas of Bushehr are vulnerable, Resilience is a factor in risk reduction and enhancing capacity in these areas. This study aims to identify effective factors in physical Resilience, and to quantify and compare physical sub-criteria in Resilience factor in the old areas of Bushehr.
Material and Methods This study is a descriptive-analytic one and its data collection tool was a questionnaire. Here, first the conception of Resilience according to the library studies (articles and books) and then physical indicators are introduced. The characteristics of this study are: availability, Resilience, quality of the buildings, and outdoor areas. Cochran formula was used to determine the sample size. 381 questionnaires, consisting of general and specific Likert-scale questions, were handed out among the residents of these areas. The reliability was calculated by Cronbach’s alpha and it was .81 which is high. To analyze the information related to resiliency of old areas, structural equation modeling and statistical analysis methods were used. They were calculated by AMOS software. To get the required map, GIS software was applied.
The Scope of the Study Bushehr is in the south of Iran. Its neighboring provinces on the north are Khozestan and parts of Kuhgiloye & Buierahmad. It is a coastal city on the north and east of the Persian Gulf, and its eastern neighboring province is Fars. It has a 625 kilometer water border with the Persian Gulf. Its population in 1390 census was over 195,222 (General census of population and housing, 1390). The total area in legal lands is 8289 hectares, 1880 hectares of which is urban area. The rest of the land is for metropolis applications (City planning consulting engineers, 1383). Bushehr is about 25359 square kilometers which contains 5.1 percent of the country and is the seventeenth big province in our country. Its population includes people in old areas of Dehdashti, Kutis, Behbahanis, Shanbadi and old neighborhoods of Aliabad, and Jafari. In addition to local residents in the old areas, there are also Afghan refugees.
Results and Discussion To examine the hypothesis, the status of physical Resilience in old areas of Bushehr was investigated based on the results of structural equation modeling analysis. Regression analysis of most physical indicators showed a fairly appropriate significant level and also the ratio of critical point and standard error were low. It was shown that the quality of buildings had the most significant effect on physical Resilience against earthquake, among other physical indicators of old areas in Bushehr. According to the results, infrastructure Resilience indicator had the strongest effect on physical Resilience (75 percent). Therefore, the above mentioned hypothesis was rejected.
Conclusion Physical Resilience is one of the effective factors in the resilience of societies, through which the status of the societies in physical and geographical aspects can be evaluated during disasters. The method used in this study was descriptive analytic approach; therefore, library studies and field surveys were utilized. The population of this study was residents of old areas in Bushehr. 381 questionnaires were handed out in these areas and the variables were analyzed through SPSS and AMOS software. The required maps were obtained through GIS software. It was hypothesized that among the physical indicators of old areas in Bushehr, the quality of buildings has the greatest effect on physical Resilience against earthquake. However, the results showed that infrastructure Resilience indicator had the greatest effect (75 percent). The results showed that the status of the Resilience in old areas of Bushehr is not good in terms of physical indicators.
To increase the Resilience in these old areas, the following points are recommended: Identifying the scope and intensity of inherent challenges which make our city vulnerable to natural disasters Identifying a set of small pieces of lands in old areas in order to make parks, to increase the access to open areas Identifying some big parks in the city in order to create central rescue stations and to equip them Widening the narrow pathways to prevent increasing urban density along the narrow pathways Applying rules for retrofitting old buildings and increasing the safety of new buildings