Verification of Recovery Process Under the Great Hanshin-Awaji Earthquake Disaster Based on the Recovery Index (Ri)
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13th World Conference on Earthquake Engineering Vancouver, B.C., Canada August 1-6, 2004 Paper No. 1381 VERIFICATION OF RECOVERY PROCESS UNDER THE GREAT HANSHIN-AWAJI EARTHQUAKE DISASTER BASED ON THE RECOVERY INDEX (RI) Yuka KARATANI1, Haruo HAYASHI2 SUMMARY This paper provides Kobe citizen's life recovery process during the seven years after the Great Hanshin- Awaji Earthquake Disaster using RI (Recovery Index). In this research, there are two steps to clarify long- term life recovery process. First, RI database is created based on various kinds of official socioeconomic statistics of Kobe and Japan. Secondly, time phase during recovery process for seven years is examined using a cluster analysis based on RI database. Finally, it is clarified that there are three time phases in the recovery process, Jan.95 - Sep.95, Oct.95 - Sep.98, and Oct.98 - Jan.02, and the life recovery situation in each time phase is examined. As a result, it is found out that the recovery trend in the latest phase seems to stabilize. INTRODUCTION Remaining tasks in Hanshin-Awaji earthquake disaster recovery policy More than eight years have passed since the earthquake occurred. In less than two years until the end of the fiscal year 2004, that is, the end of Hanshin Awaji Earthquake Recovery Plan Period, we are required to achieve the remaining tasks, and to carry the mechanism created and extended during the earthquake recovery process forward to the mature society of the 21st century. In December 2002, the Administration of Hyogo Prefecture, the area affected by the disaster, formulated "Hanshin-Awaji Earthquake Recovery Plan Final Three-Year Promotion Program" as it faced with the last stage of the target period for the recovery [1]. This program defines and summarizes the basic concept and tasks for the remaining three years, the direction of measures for achieving the remaining tasks and the projects to be carried out mainly by the prefecture in three years. The important task, it points out, is to deliberate on the direction of measures that should be carried forward from the "recovery plan" to the "general plan". For example, in the Hyogo Prefecture "Latter Five-Year Promotion Program" [2], projects which had been considered as recovery measures have been narrowed down to be addressed as general measures (top priority measures: 288 projects, estimated project cost for three years: approx. 730 billion yen). Kobe city, aiming recovery in 10 years after the disaster, will also implement “Recovery Roundup and Verification (tentative title)” from this fiscal year on. In this program, the main subject, again, is to objectively grasp the recovery status of 1 Research Associate, Graduate School of Engineering, Kyoto University, Japan 2 Professor, Disaster Prevention Research Institute, Kyoto University, Japan the disaster-stricken area, to define the general idea of recovery measures, to narrow them down and to carry them on as general measures. Viewpoints required for grasping the recovery status To analyze the recovery issues as we have discussed so far, we are required, first of all, to grasp the recovery status of the disaster-stricken area in multifaceted and objective manner. In “Kobe City Earthquake Disaster Recovery Roundup and Verification” [3], [4], which was implemented in 2000, "the Sector of Life Reconstruction", points out the necessity to define the concept of life reconstruction, and to proceed with verification, it discusses the specific theme: "what is life reconstruction?" in the first place. It explains the basic structure of life reconstruction during the recovery process in the following manner: "Life reconstruction" has a complex structure intertwining in with many other areas taken up in "Kobe City Earthquake Disaster Recovery Roundup and Verification". The basic structure is shown in Figure 1. The figure shows that the structure has recovery of infrastructure, the very basic issue in the process of recovery from the disaster, as the bottom layer, then reconstruction of individual houses and the city, revitalization of economy and measures to support medium and small-sized enterprises, all of which influence the reconstruction of the victims’ life. In addition, the victims’ life itself creates a specific problem associated with life reconstruction, which adds further complexity to the structure of "life reconstruction." The sector points out that, for this reason, it is difficult to define "life reconstruction" in short, and that it could not be easily grasped so far. It also makes it clear that seven factors of life reconstruction, i.e., "housing", "social network", "livelihood", "mind and body", "disaster preparedness", "government response", and "land use management" constitute the items to be verified regarding this difficult-to-define theme of “life reconstruction.” Accordingly, in grasping the life reconstruction status, it is considered important that we take a multifaceted approach. Life rehabilitation of victims Measures to Revitalization support medium Reconstruction City planning of economy and small-sized of houses enterprises Recovery of infrastructure Figure 1 Basic Structure of Life Reconstruction [3], [4] Source: Kobe City Earthquake Disaster Recovery Roundup and Verification: Sector of Life Reconstruction Attempt of quantification with indices to indicate the life reconstruction status Karatani et al. (2000) [5] proposed the Recovery Index (RI) that can take the aspects as mentioned above into consideration, applying the concept of People's Life Indicators (PLI). And we tried to grasp the recovery process of Kobe city during the four years after the earthquake, using 120 types of socioeconomic statistics. As a result, the influence of the Hanshin-Awaji Earthquake Disaster in Kobe city could be roughly classified into 6 types of recovery and restoration status according to two factors: the size of drop immediately after the disaster and the extent of recovery afterwards. We also examined the recovery process in view of the nineteen items such as construction, transportation and export and import, included in the six recovery patterns. In examining the recovery status, however, there remain the following two questions: 1) By using RI, they only classified them into two groups: those that drop immediately after the earthquake, but return to the level before the earthquake (winner group), and those that did not return to the level before the earthquake (loser group). But what kind of situation do they regard as “recovery”? 2) In either group, the indices tend to stabilize with time whether it is a winner group or not (i.e., returning to the level before the earthquake or not). Is a similar stable trend still observed even when the latest data is added? Accordingly, in this paper, we used the RI database added with the latest data in the three years until January 2002 to verify the recovery process in Kobe city during the 7 years after the disaster. By clarifying the transition of recovery process patterns with time after the earthquake, we examine the concept of recovery as the tenth year of recovery after the disaster draws near. OUTLINE OF METHOD TO ESTIMATE RECOVERY INDEX (RI) Viewpoint for grasping the “life” Generally, published socioeconomic statistic values differ in unit or range of variation, so the correlation of indices cannot be compared easily. Accordingly, to standardize various indices, we adopted the concept of People's Life Indicators (PLI) proposed by the Social Policy Bureau of the Economic Planning Agency [6]. PLI was developed with a view to grasping the various aspects of people’s life in detail as well as the actual living conditions and characteristics of the local communities and to contributing to the improvement of the nation’s quality of life. The indices are used as a reference in discussing the question: “what is affluence in a real sense?” To be more precise, it classifies various socioeconomic statistics that show the nation’s living conditions are objectively and systematically into 8 areas of life activities: "dwelling", "spending", "working", "bringing up (children)", "healing", "playing", "learning", "socializing", and expresses them quantitatively by standardizing each index. We considered that this concept of PLI is similar to the seven factors of life reconstruction that were made clear in Kobe city in that they grasp the living conditions in a multifaceted and quantitative manner. Accordingly, in this paper, we employed the method proposed by PLI for standardizing respective socioeconomic statistics. Calculation method of standardized index The standardized index is the value obtained by standardizing the rate of conversion so that the average of the absolute value of the rate of conversion in each month during the period of the survey equals 1, and by processing the rate of conversion of each month cumulatively, assuming the level of the reference month (here, December 1994) as 100. The method to standardize each index is as explained below. a) Calculation of centered rate of conversion Ci(t) Firstly, classify the method of calculation into two types based on the characteristics of respective indices Di(t), and calculate the centered rate of conversion Ci(t). The centered rate of conversion stands for the rate of conversion centered with regard to each index Di(t). ・CASE 1: when the index is an ordinary index or indicates the actual level itself Di(t) − Di(t − 1) Ci(t) = ×100 Di(t) + Di(t − 1) [1-a] 2 where Di(t): each index, i: index number, t: time, Ci(t): centered rate of conversion. ・CASE 2: when the index is a ratio or 0 value or negative value Ci(t) = Di(t)-Di(t-1) [1-b] b) Calculation of standardization factor (Ai) N ∑ Ci(t) t=2 Ai = [2] N −1 where N: Number of time points during the standardization period. In this paper, the period of standardization is the period of 81 months from April 1992 to December 1998, hence N=81, Ai: standardization factor (weighted average of absolute value of rate of conversion).