Japan Geoscience Union Meeting 2022

Presentation information

[J] Poster

H (Human Geosciences ) » H-DS Disaster geosciences

[H-DS09] Human environment and disaster risk

Mon. May 30, 2022 11:00 AM - 1:00 PM Online Poster Zoom Room (14) (Ch.14)

convener:Hiroshi, P. Sato(College of Humanities and Sciences, Nihon University), convener:Takayuki Nakano(Geospatial Information Authority of Japan), Chairperson:Hiroshi, P. Sato(College of Humanities and Sciences, Nihon University), Takayuki Nakano(Geospatial Information Authority of Japan)

11:00 AM - 1:00 PM

[HDS09-P03] Survey on the amount of work done by volunteers in earthquake disasters

*Yoshinobu Mizui1,2, Hiroyuki Fujiwara1,2 (1.University of Tsukuba, 2.NationalResearch Institute for Earth Science and Disaster Resilience)

Keywords:Self-help, mutual aid, disaster volunteers, Mashiki Town, Hirakata City

1. Introduction
Since the Great East Japan Earthquake on March 11, 2011, we have been involved in the operation of disaster volunteer centers in various places, but we found it difficult to adjust the actual amount of work and the number of victims in the disaster area. To solve this problem, it is important to understand the amount of work required for self-help and mutual support and the total number of activists, and to clarify the breakdown of the total number of mutual supports.
In this study, we investigated the number and content of disaster volunteers in Mashiki Town during the 2016 Kumamoto Earthquake and Hirakata City during the 2018 Northern Osaka Earthquake, and examined differences in disaster scale and between urban and suburban areas. In Mashiki Town, we used the damage classification of houses based on the "Investigation of building damages caused by the 2016 kumamoto earthquake utilizing aerial photographic interpretation" by Naito et al. (2018) to compare the characteristics.

2. Survey method
The total amount of work done by disaster volunteers will be ascertained by utilizing the work management data of the disaster volunteer center implemented after a disaster occurs. Estimate the amount of breakdown for each type of work. In the Kumamoto earthquake, aerial photographs were used to decipher the damage to buildings. The amount of work and the content of work for each damage category were visualized in a graph for the entire period from the opening to the closing of the disaster volunteer center, using a one-week period as the unit. In terms of the scale of the disaster, Mashiki Town, which experienced two consecutive intensity 7 earthquakes, and Hirakata City, which experienced a relatively minor earthquake with an intensity of just under 6 on the Japanese scale, are distinctive.
In terms of regional characteristics, Mashiki Town, a suburban town adjacent to Kumamoto City, and Hirakata City, a town along a major railroad line in Osaka Prefecture, are two examples.
We examined these characteristics and the differences in work volume, content, and work time. Since Hirakata City is composed of urban areas, Mashiki Town will also be compared by cutting out the data of urban areas.
Damage classification of buildings by aerial photographic interpretation is based on Naito et al. (2018).
LEVEL1: No damage according to aerial readings.
LEVEL2: roof tiles partially collapsed or blue sheets covering less than half the roof area.
LEVEL3: Most of the roof tiles have collapsed, walls have fallen, or blue sheets cover more than half of the roof area.
LEVEL4: Buildings can be seen to be tilted or twisted, or their height has changed by more than 3 meters before or after the main shock.
LEVEL 0 indicates that the house cannot be compared before and after the reading photo, or that the building is too small to be legible.

3. result
As a result of comparing the two cities and towns in the graphs created, the following characteristics were discovered.
In Mashiki Town, Kumamoto Pref.
(1) LEVEL 0 and 1 are mainly support at evacuation centers and town halls.
(2) LEVEL2 and 3 are mainly outdoor repair work.
(3) LEVEL3 is continuing to generate work until April 2017.
(4) LEVEL 4 is less indoor cleaning and tidying work.
(5) There is work to remove valuables.

In Hirakata City, Osaka Pref.
(1) In the second week after the opening of the Disaster Volunteer Center, Mashiki Town received about 80 needs and Hirakata City received about 120 needs, with Hirakata City receiving more needs per week during the peak period.
(2) Some needs are so simple that they can be completed by responding to inquiries by phone.
(3) The ratio of outdoor work tends to be higher than indoor work.

We would like to express our sincere gratitude to the social welfare councils of Mashiki Town and Hirakata City and their supporters for preparing the work management data for the disaster volunteers.