Damage, Information Acquisition Route, and Reconstruction Under the Great East Japan Earthquake-The 1st Survey of Nuclear Disaster Evacuees from Futaba, Fukushima, Summary of Results 2013　|ニッセイ基礎研究所

1――Basic Information

Surveys on the damage, living environment and reconstruction under the Great East Japan Earthquake have been conducted via a research project called the "International comparison of reconstruction of living infrastructure from disasters" (Yasuyuki Sawada, Professor, Graduate School of Economics, The University of Tokyo; Keiko Iwasaki, Researcher, NLI Research Institute) of the University of Tokyo since 2013. The surveys target all household heads of Futaba in Fukushima prefecture, where all residents were forced to evacuate due to the nuclear power plant accident caused by the Great East Japan Earthquake that occurred in 2011. Surveys were conducted in July 2013, December 2014, July 2016, December 2017 and July 2019. This paper reports the summary of results of the first survey conducted in July 2013.¹

The survey includes questions about basic attributes such as age and gender, as well as questions related to connections with others (social capital) and health conditions (see the appendix at the end of this report for all the questions included in the survey). The questionnaires were distributed to all households of Futaba (about 2,900 households) that receive the regular town mail from Futaba. We received responses from 585 Futaba residents who had evacuated nationwide (the response rate was about 20%).

The survey targeted heads of households and Figures 1 and 2 show the distribution of age and gender of the respondents. As we can see from these figures, compared to the age and gender distribution reported in the national census, the age distribution of the respondents is left-skewed, with the majority of respondents in their 60s. The gender distribution shows that the majority of respondents are male. In addition, since the survey was conducted after the tremendous disaster, it is possible that the distributions of the respondents' characteristics are significantly different from those of general questionnaire surveys. Therefore, it should be noted that the results of this survey do not necessarily indicate the general trend of Futaba residents.

Figure 1: Age Distribution of Respondents/Figure 2: Gender distribution of Respondents

¹ This research was supported by the following research grants.
　Grant-in-Aid for Scientific Research (15 J09313, 26220502, LZ003), Research Grants of the Japan Center for Economic Research.
　This study is approved by the Ethics Committee of the University of Tokyo (19 -73).

2――Change in Social Capital

Social capital refers to trusting relationships and networks, and is sometimes referred to as "kizuna" in Japanese. Social capital is getting attention as a key notion to achieve successful disaster recovery and has been one of the major focuses of our study. The survey results show that social capital might have been weakened by the disaster among Futaba residents.

There are several indicators that are commonly used to measure social capital, but we focused on three items which are the level of "generalized trust", "frequency of mutual assistance with neighbors" and "participation in hobby activities". As shown in Figure 3 to 5, all of these three indicators show that social capital has weakened because of the disaster. In addition, our further analysis show that the frequency of mutual help and participations in hobby activities decreased especially among those who do not have many neighbors from Futaba at the evacuation destinations.

Figure 4: Frequency of Mutual Assistance with Neighbors

Figure 5: Participation in Hobby Activities

3――Health Condition

We included a question asking changes in health condition compared to pre-disaster status. As shown in Figure 6, many respondents rated their own health condition as worse than that of their pre-disaster status.

Figure 6. Change in Subjective Health Status

As for mental health, the distribution of K6 score, a clinically validated index for diagnosing the overall stress state, shown in Figure 7 indicates that K6 scores of Futaba residents are much higher compared to those for Japan. (K6 is an internationally used measurement for general mental health status that consists of six questions. The higher the total score, the more likely the respondent is stressed.)

Figure 7: Distribution of K6 Score for Futaba and Japan

K6 score distributions have been reported in disaster affected areas other than Futaba by the Government and local governments as well. As shown in Figure 8, K6 scores of Futaba residents tend to be higher than those of residents in other disaster affected areas, such as Ogatsu and Ojika area of Ishinomaki and Yamada where the damages caused by the tsunami were tremendous. We believe that manmade disaster could have more serious and longterm impacts on victims’ mental health status.

Figure 8: Distribution of K6 Score for Futaba and Other Disaster Affected Areas

However, the results of this survey do not necessarily apply to all residents of Futaba, and a high K6 score does not necessarily mean that one has a mental disorder. Please note that the purpose of our survey is to provide policy implications to the Government or other administrative agencies.

Moreover, with further analysis, we found that those who could keep good subjective health status after the disaster, those who have high income after the disaster and those who could keep high level of generalized trust tend to keep good mental health status after the disaster.

In addition, hearing from some Futaba residents about their psychological distress caused by the substantial deduction of their living space at evacuation destinations compared to homes they used to live in Futaba, we tested if the deduction of living space led psychological distress among Futaba residents using our dataset. As a result, even after controlling for age, gender and income level, we found that those who used to live in larger homes in Futaba tend to have higher K6 scores after the disaster. In other words, those who used to live in larger homes before the disaster tend to be under higher stress after the disaster. The result empiricaly supports the opinions of Futaba residents that the deduction of living space caused by the disaster led psychological distress among Futaba residents.

We intend to continue our analysis and contribute to the improvement of disaster preparation/rehabilitation policies.

Our survey results are based on aggregates and analyses of responses from approximately 20% of the households of Futaba and do not represent all Futaba residents. Since the survey was conducted after a major disaster, the characteristics of respondents may be very different from general surveys and there is a possibility of an overestimation in our results due to the deterioration of physical and mental health conditions. Therefore, special caution is required in interpreting the results, and any definitive judgments based solely on these findings should be avoided.

Damage, Information Acquisition Route, and Reconstruction Under the Great East Japan Earthquake-The 1st Survey of Nuclear Disaster Evacuees from Futaba, Fukushima, Summary of Results 2013 | ニッセイ基礎研究所