DEIM Forum 2014 P3-5

Analyzing Dissemination Processes ofMail-based Disaster Information Systems-A Case Study of Typhoon Man-yi in 2013Kota TOMOYASU† , Yuanyuan WANG† , Reo KIMURA†† , and Kazutoshi SUMIYA††† Graduate School of Human Science and Environment, University of Hyogo
1–1–12 Shinzaike–honcho, Himeji, Hyogo, 670-0092 Japan†† School of Human Science and Environment, University of Hyogo
1–1–12 Shinzaike–honcho, Himeji, Hyogo, 670-0092 Japan
E-mail: †{nd13y015,ne11u001}@stshse.u-hyogo.ac.jp, ††{rkimura,sumiya}@shse.u-hyogo.ac.jp
Abstract Japan’s recent disaster response management planning eﬀorts have focused on non-structural measures.
Many local governments often disseminate evacuation information through mail-based disaster information systems.
Local governments make evacuation announcements based on their best judgment, and after that, they disseminate
these announcements further using e-mails. However, there are no format of mail-based disaster information systems, and it has proven diﬃcult to disseminate the appropriate evacuation information at the right time. Further,
there are no current studies focused on developing a more suitable and eﬀective management of mail-based disaster
information system. We intend to analyze problems associated with current disaster information systems?with theobjective of being able to recommend improvements?by focusing on actual evacuation information dissemination
processes of mail-based disaster information systems. We begin with a survey of the actual content and timing oftext messages issued by local governments. In this way, we are able to identify diﬀerences between text messages
and time delays in the dissemination of evacuation information by local governments. Our case study is based on asurvey of the evacuation information dissemination processes used in the case of Typhoon Man-yi (2013).
Key words disaster response, evacuation information, dissemination processes, e-maila necessary component of disaster management measures.

1. Introduction

However, there are no guidelines outlining how a mail-based

Japan’s recent disaster response management planning ef-

evacuation information system should operate. As a result,Many lo-mail-based evacuation information systems are managed dif-

cal governments often disseminate evacuation information

ferently in each local government. To date there has not

through mail-based disaster information systems, and lo-even been any discussion about what the components of ancal governments are responsible for helping residents de-appropriate evacuation information system would be, andcide whether to evacuate [1]. The communication of evac-

consequently most local governments do not manage theiruation information is a stepwise process, made up of phases.

mail-based evacuation information systems very well.

forts have focused on nonstructural measures.

These phases are implemented according to the severity of

The objective of this paper is to break down the problems

the disaster; speciﬁcally, local governments implement dif-associated with these information systems, so that we canferent phases as needed, to keep residents informed of theunderstand them better, and suggest improvements. We be-severity and potential dangers of the unfolding disaster. As

gin by analyzing existing mail-based evacuation information

depicted in Figure 1, there are three phases: ﬁrst, dissem-

dissemination processes. We survey the case of Typhoon

inate evacuation preparation information; second, issue an

Man-yi 2013 ﬁrst. Using our survey results, we analyze theevacuation advisory; and third, issue an evacuation order.

evacuation information systems that were used, focusing on

Many local governments issue their evacuation information

the timing of dissemination and the contents of the text mes-

using e-mails. Currently, many residents use mobile devices,

sages sent.

so they can receive information wherever they are.

For

While some studies have focused on evacuation informa-that reason, optimal dissemination processes have becometion systems, no studies have been based on surveys and anal-

Disaster Severity
Evacuation
Preparation
Information

Evacuation
Advisory

governments had disseminated and when.
Evacuation
Order

We concluded that the local governments that had provided us with their evacuation information dissemination
dates quickly and correctly were the governments most ca-

Figure 1 Evacuation information phasepable of disseminating evacuation information. Other local governments did not provide their dates, and did notyses of actual evacuation dissemination processes. Tauben-summarize their evacuation response records as requested.

bock developed the evacuation information system for early

Even worse, one local government tampered with its data.

warning [2], Gunaman and Watanabe developed the system

It was apparent that evacuation information disseminationfor evacuation guidance [3] [4]. The roles of these systems areproblems existed even among otherwise capable local gov-

diﬀerent from mail-based disaster information systemes. The

ernments.

role of mail-based systems are dissemination.Kodama examined the eﬀectiveness of evacuation information phases andfound them to be eﬀective [5]. Yabe examined appropriate

3. Analysis of the Evacuation Information
Dissemination Processes

evacuation information related to the speciﬁc characteristics

In this study, we analyzed evacuation information dissem-of regional ﬂooding [6]. Katada analyzed residents’intentions

ination processes with a focus on their timing and message

to acquire disaster information in the event of ﬂooding [7].

contents. Timing of the dissemination allowed us to judge

Ushiyama analyzed undeerstanding of intarnet users for havy

whether residents obtained information quickly and so were

rainfall disaster information [8].

Ohta investigated heavy

better able to decide when to begin evacuating; message con-rainfall disaster information provided by local governments

tent allowed us to assess whether residents were able to assessthat did not focus on mail-based systems [9].

their levels of risk accurately. By analyzing the data we had

In the next section, we summarize our survey of existing
mail-based evacuation information dissemination processes.
Section 2 explains how we analyzed these processes by focusing on the timing of the dissemination and the contents

collected, we were able to document on-going problems withthe dissemination processes.
3. 1 Timing of Evacuation Information Disseminationof the text messages sent. Section 3 suggests improvements

The ﬁrst point to be discussed is whether local gov-

to the mail-based evacuation information systems. Finally,

ernments disseminated evacuation and weather information

Section 4 concludes this paper with suggestions for future

within suitable time frames. As depicted in Figures 3 and 4,

research.

we used the results of our survey to summarize the evacua-

2. Survey Overview
We surveyed the case of Typhoon Man-yi that formed

tion information dissemination processes of each local government. Weather information consisted of JMA announcements that had been used by local governments to decide

on September 13, 2013, and struck Japan on September

whether to issue evacuation notices [11].

16 (see Figure 2). Several regions suﬀered serious damage

nouncements that had been disseminated and were subse-

from this typhoon. It resulted in 6 deaths, 1 missing per-quently cancelled were entered into the timetable, if theson, and the destruction of 11,739 residences. Kyoto Pre-

information had been disseminated by e-mail. Evacuation

fecture, Shiga Prefecture, and Fukui Prefecture announced

information consisted of local governments’announcements

heavy rain Emergency Warnings. Emergency Warnings areproviding on weather information and the actual conditions

weather bulletins issued by the Japan Meteorological Agency

in each region. As with the JMA announcements, local gov-

(JMA) [10], to alert people to the signiﬁcant likelihood ofernment announcements that had been subsequently can-catastrophes associated with natural phenomena of extraor-celled were entered into the timetable if the information had

dinary magnitude.

been disseminated by e-mail. Mail dissemination consisted

Evacuation an-

We collected three types of disaster response data fromof local governments’distribution of information, mainly witheach of the three local governments, and studied the contents

regard to evacuation. The arrows in the ﬁgures reﬂect theof text messages sent from Kyoto and Shiga Prefectures. The

paths linking disaster response activities. There are three

three types of data collected were: what weather information

path patterns. The blue paths represent weather informa-

had been announced and when (the JMA announces weather

tion being transmitted into evacuation information, and re-information to help local governments judge whether theyﬂect the time lapse between timing of the issuance of weather

should issue evacuation notices [10]); what evacuation infor-

information and the issuance of corresponding evacuation

mation had been issued and when; and what mailings local

notices. The black paths represent the transformation of

Fukuchiyama

Ayabe
Yasu

Figure 2 Tracks of Typhoon Man-yi in 2013

evacuation information (whether evacuation preparation no-

were lengthy delays with regard to some disaster responses.

tices, advisories, or orders) to mail communication, and show

This indicates that weather information is not an absolutethe time delays between the issuance of evacuation bulletins

trigger for issuing evacuation advisories. This response wasand their dissemination by mail. The green paths represent

common in other cases.

the time between the issuance of weather information to the

The slopes of the paths from issuance of the evacuation

time this information was disseminated by mail, and they

advisory to mail dissemination of that advisory were very

show the delays between the time the weather information

small, that is, there was virtually no delay between the two

was announced to the time the corresponding mailings wereactivities. Based on this fact, Fukuchiyama disseminateddisseminated. The relative slopes of the diﬀerent paths rep-

evacuation advisory mailings very quickly. Their dissemi-

resent the relative time delays between the various activities;

nation coincided with the decision to issue the evacuationthat is, as the slopes increased, the delays were greater.

advisory.

3. 1. 1 Case 1: Fukuchiyama

Contrary to the path slopes describing a path from the

Fukuchiyama is a city in Kyoto Prefecture (see Figure 2)

issuance of evacuation advisories to mail dissemination, thewhere evacuation information dissemination followed all ofpath slopes from weather information to mail dissemination

the patterns described. The path slopes from receiving thewere very large. The JMA called oﬀ a heavy rain emergency

weather information to issuing this information as evacuation

warning at 9:55 (JST) on September 16, and Fukuchiyama

advisories or orders were not large on average, which suggests

disseminated a mailing of this information at 22:15 (JST)that Fukuchiyama’s evacuation dissemination processes wereon the same day, 12 hours and 20 minutes later. In con-timely. However, some large diﬀerences were noted. For

trast, a heavy rain warning was called oﬀ at 19:15 (JST) on

example, JMA announced a Level 3 ﬂood forecast that trig-

September 15, and Fukuchiyama disseminated the mailinggered an evacuation advisory at 2:15 (JST) on September 16,of this information at 19:45 (JST) on the 15th. The delay

and Fukuchiyama announced an evacuation advisory at 2:20

in this case, was small. It is evident from these data that no(JST) on the same day. In contrast, a Level 2 ﬂood forecast

mail-based information management system had been estab-that should have triggered an evacuation preparation advi-lished, and this lack of consistent management practices led

sory was announced at 23:50 (JST) on September 15, but

to problems.

the corresponding evacuation preparation advisory was not

3. 1. 2 Case 2: Ayabe

announced until 1:10 (JST) on September 16. Thus, there

Ayabe is a city in Kyoto Prefecture (see Figure 2) that

issued both evacuation preparation notices and evacuation
advisories. The slopes of the paths representing the issuanceation is•Continued updates on evacuation information as newof evacuation preparation notices to their dissemination by

information becomes available

mail are small, meaning that the delays were short. However,

These additional points are important because it is necessary

there are some comparisons to be made with Fukuchiyama.

to communicate how much the hazard is increasing (or de-

The short delays were always of the same length?roughly 10

creasing), and for people to understand the meaning of theminutes. This tendency is characteristic of Ayabe . The

evacuation information being provided, in order to perceive

delays in disseminating mail were an obvious problem, com-the risks correctly. Especially with regard to evacuation in-

pared to the delays in issuing evacuation notices. It is notformation, many residents do not understand the diﬀerent

necessarily appropriate to suggest that the issuance of evacu-

meanings inherent in each of the three evacuation informa-ation notices was delayed by the timing of the announcementtion phases [11]. In Japanese, evacuation advisories are calledof weather information. Issuing evacuation notices is based

Hinan (evacuation), Kankoku (advisory), and evacua-

not only on weather information, but also on each region’stion orders are called Hinan (evacuation) Shiji (order).

actual situation. However, mailings should be disseminatedResidents ﬁnd Kankoku more compelling than Shiji, which

without delay, following the issuance of evacuation notices.

is one of the reasons that residents do not understand the

Although the delays were not great, when disaster severity

diﬀerent evacuation information phases. However, there wasis known early, delays in issuing evacuation information, no-nothing that explained these two matters in the data we col-tices, or advisories can lead to serious damage.

lected.

Disaster responses diﬀer among local governments, de-Now, we would like to examine actual text messages. Fig-

pending on the delays between issuing evacuation prepara-ures 5 and 6 show excerpts from actual text messages dissem-tion information, notices or advisories, and the time at whichinated by local governments, i.e., Fukuchiyama and Ayabe.

this information is disseminated by mail. Local governments

3. 2. 1 Case 1: Fukuchiyama

have no format of mail-based evacuation information dissem-

Fukuchiyama disseminated all types of evacuation infor-

ination process, nor does such a process exist. Moreover, inmation. In all of its messages, the evacuation information

Fukuchiyama the local government’s approach to mail dis-

was explained, including who should evacuate, as in the fol-semination of weather information is inconsistent. There islowing example: “This siren announced evacuation prepara-no national or local government format for managing thistion information to the Yura river valley area.” Nevertheless,information.

apparent inconsistencies in the evacuation information were

3. 2 Contents of Text Messages

not explained. In brief, the messages providing evacuation

The following discussion regards the evacuation prepara-

information were not easy to understand. Moreover, it wastion information, notices, and advisories sent by text mes-

unclear when the evacuation preparation information had

saging. We analyzed the contents of the disseminated text

been announced. “This siren” indicated that Fukuchiyama

messages for suitability. “The Guidelines for Producing arang the siren when they announced the evacuation prepa-

Decision and Dissemination Manual for Evacuation Advi-ration information. Thus, the residents who had not heard

sories and Orders” [1] itemizes the information that should

the siren did not know the exact time of the announcement.

be provided to residents as follows:

Local governments should show exactly when the siren had•

Time of the announcement

been sounded. Without understanding what was meant by•

Who is sending the announcement

the diﬀerent types of evacuation information, residents could•

Who should evacuate

not respond appropriately, even after they had received ex-•

Why they are being asked to evacuate

planations regarding the speciﬁc evacuation information be-•

How dangerous the situation is

ing announced.

•

In what order the evacuation will be conducted•

When the evacuation will commencewith its evacuation information dissemination process. For•

Where the evacuation areas are locatedexample, one evacuation advisory message stated, “A disas-•

What the evacuation route is

ter may occur.”, while on the other hand, in a subsequent•

Required behavior of evacuees

message about the evacuation advisory, it was stated that “A•

Person in charge of dissemination

serious disaster may occur.”. Risks were emphasized in the

However, Fukuchiyama explained the risks more clearly,

In addition to this information, we consider that the follow-

evacuation order message. We concluded that these types ofing information must also be provided:

messages promoted accurate risk perceptions.

•Continued updates regarding how hazardous the situ-

Additionally, hazard levels at the time were highlighted

Figure 3 Timetable of Fukuchiyama

in all messages as the reasons to evacuate. For instance,

ferences in hazard conditions were not explained. In ad-“The water level has exceeded 4m, and it may continue todition, there were particular problems in the case of Yasu.

rise.” However, implications of the hazard conditions were

Yasu notiﬁed residents as the situation moved from one evac-

not explained. In brief, messages mentioned the current haz-uation phase to another, for example, “The evacuation orderard conditions, but did not mention how the conditions had

was shifted to an evacuation advisory at 12:10.”.

changed, or what the conditions implied in terms of risk. It

Diﬀerences between diﬀerent types of evacuation informa-

was diﬃcult for residents to understand the seriousness oftion were mentioned, but what the diﬀerences meant was

the risks when they were told only what the speciﬁc hazard

not clariﬁed. Therefore, without understanding the evac-

conditions were, such as “The water level has exceeded 4m.”

uation information they had received, residents could notor “The water level has exceeded 5m.”.

understand the information they had been given regarding

3. 2. 2 Case 2: Yasu

the diﬀerences between the three evacuation phases. Even

Yasu is a city in Shiga Prefecture (see Figure 2). Yasu

further complicating matters, Yasu did not disseminate any

disseminated evacuation preparation information, and thenissued an evacuation order, which was later replaced by anevacuation advisory. In common with Fukuchiyama, the dif-messages regarding its evacuation order.

Figure 4 Timetable of Ayabe

4. Suggested Improvements
based Systems Operation

of

Mail-

lish criteria that must be met in order to ensure the timely
announcement and dissemination of evacuation information.
It should be noted that relaxing the criteria for announce-

The results of our analysis clearly show that there are aments would not be an eﬀective strategy. Relaxing the cri-

mail-based sys-teria would lead to declining public trust in the evacuation

tems operation. We would like to propose a number of im-

information provided, because of an increase in the num-

provements from two points of view, namely, the timing of

ber of cases in which a serious disaster did not occur, eventhe dissemination of evacuation information, and the content

though evacuation information announced the possibility ofof the evacuation-related text messages. We show the pro-a disaster. For example, one criterion for announcing evacu-

posal format of the mails for improvement(see Figure 7) andation preparation information occurs when a heavy rain ad-

discussed in detail below.

visory is issued, but heavy rain advisories are announced fre-number of problems in local governments

4. 1 Timing of Dissemination

quently, even when heavy rains do not lead to serious disas-

In circumstances of disaster, the timing of evacuation in-ters. Therefore, in most cases using relaxed criteria, residents

formation announcements and mail dissemination can have

do not suﬀer any damage even though evacuation prepara-signiﬁcant implications. Therefore, it is necessary to estab-tion information has been announced. This confusion leads

Evacuation Preparation Infoamation(9/16 1:10)
This is the Fukuchiyama disaster watch headquarters.
This siren indicate the need for evacuation preparation information in the Yura rivervalley area.
The water level has exceed 4m and may continue to rise.
Residents－in areas at risk of flood and sediment disaster－who may find it difficult totravel, such as the elderly and those who are ill should evacuate to a nearby shelter.
Please bring essential items to the shelters: food, water, and medicines.
Prepare to evaluate from there and keep abreast of the situation.
The Fukuchiyama disaster watch headquarters disseminates evacuation preparation
information.
Evacuation Advisory(9/16 2:10)

This is the Fukuchiyama disaster watch headquarters.
The present siren announced evacuation advisory to the Yura river valley area.
The water level exceed 5m and it may go up from now.
A disaster may occur.
Those living in regions at risk of flood and sediment disaster need to evacuate to a
nearby shelter.

＜Timing＞＜Announcement Time＞＜Dissemination Time＞＜Delay＞＜Contents of evacuation information＞＜Difference from Previous Mail＞＜Hazard Progression＞＜Evacuation Phase＞＜Objective Region＞
e.g.)

Evacuation Order(9/16 5:40)

This is the Fukuchiyama disaster response headquarters.
This siren present indicates the evacuation order for the Fukuchiyama whole region.
Now, the heavy rain emergency warning is announced.
A serious disaster may occur.
The water level of Yura river has exceed 7m -- the water level exceed 7m and continue
to rise. It is unsurprising whenever a serious disaster occur. Residents in regions at risk
should complete evacuation immediately.
However, when you take evacuation, be fully careful.
Conduct the evacuation carefully: do not use force; take the minimum action required
to protect your life, such as moving to safe place as quickly as possible.

Figure 5 Text Message of Fukuchiyama

Figure 7 Proposal format

4. 2 Contents of Text Messages
As mentioned above, we consider that the particularly important aspects of text message contents are information
on changing conditions and what the implications of thosechanges are. However, in our analysis, these points were not

Evacuation Preparation Infoamation(9/16 10:41)

Since the water level of the Yasu river crossed the flood cautions water level at 9:17
a.m. today, evacuation preparation information was announced.
The elderly and children need instructions for evacuatioin.
The object region is as follows.
Mikami school district: Omifuji, Shichikenjo, and the evacuation shelter is Commucen
Mikami.
Yasu school district :evacuation shelter is Commucen Yasu.
Kitano school district: Ichimiyake, Takejo school district , and the evacuation shelter is
Commucen Kitano.
From Yasu Life safety division

Evacuaon Order → Evacuaon Advisory(9/16 12:53)

mentioned in all messages. With regard to weather information, residents may not understand the speed at which thehazard is progressing. We propose to explain and highlightthe changing hazard levels and their meanings. For example:“The water level exceeds 5m. It has risen 1m since the previous mail was disseminated. Its speed is very dangerous.”
Messages like this can help residents understand the details

Omifuji, Shichikenjo of the Mikami school district, the Yasu school district, Ohata, Yasu,
the Kitano school district, Ichimiyake, Takejo, and Takegaoka cancelled evacuation
preparation information announced in these regions at 12:10.
Moreover, the Shinohara school district, Irimachi, Takagi, Nagashima, Kominami, andfront of Shinohara Station, the evacuation order was revised as evacuation advisory at
12:10.
Since the water level of Hino River is high, since it is high, cautions are before required
enough.
From Yasu Life safety divisionof hazardous conditions. Similarly, concerning evacuation in-

Figure 6 Text Message of Yasu

ration to evacuation advisory.” This additional information

formation, many residents may not understand the context
of evacuation information messages without some explanation. We propose to provide information explaining whether
evacuation phases are progressing or receding, for example,“The evacuation phase has advanced from evacuation prepawill help residents understand the increasing or decreasing

residents to think that they are not in danger, even thoughlevels of risk they face.Moreover, it is consideredthat show-

evacuation information has been announced. Therefore, it ising objective region of evacuation information is eﬀective.

important not to relax the criteria too readily.

Finally, we consider that it is important to express the risks

Moreover, if there are delays in mail dissemination, local

emphatically, as in the case of Fukuchiyama, because thisgovernments should tell residents what the length of the de-lets the residents know that the situation is unusual. Whenlay will be, because it is possible that residents will not re-disasters occur, people often have mistaken perceptions be-

alize that the disseminated announcement has been delayed.

cause of normalcy bias [12] [13]. Normalcy bias leads to an

In these cases, residents may make mistakes in the timing

underestimation of risk, which in turn tends to cause peopleof their evacuations. For example, a message such as “an-to consider that conditions are normal. Thus, expressing thenouncement time 19:15; dissemination time 19:45; delay isrisks emphatically will cause people to understand them bet-

30 minutes” would help residents judge the timing of theirter, and will help to eliminate normalcy bias [14]. For that

evacuations because they clearly know of the delay. residents

reason, we propose to add emphatic expressions of the level

judge the timing of their evacuations because they clearlyof risk in messages, as does Fukuchiyama.

perceived the delay.

5. Conclusions and Future Works
In this paper, we analyzed evacuation information dissemination processes by focusing on their timing and content,
using cases from Typhoon Man-yi in 2013.

We clariﬁed

the problems that we had identiﬁed by analyzing our data.
Moreover, we identiﬁed necessary improvements using ouranalyses. Concerning the timing of evacuation information
dissemination, we concluded that it is important to establish
criteria for announcing and disseminating evacuation information, and to clearly explain long delays in dissemination.
Furthermore, concerning the contents of text massages, weconcluded that it is important to provide explanations concerning the changing weather conditions, and to clarify what
the evacuation information means for the recipients, including the meanings of terms used in the message. The clariﬁcation of risk should also be improved.
In future research, we will study the eﬀectiveness of the improvements that we have proposed, and examine the timing
delays in more detail. Several factors may contribute to thedelays. For instance, there is the relationship between the
delay in announcing evacuation information and the evacuation information phase. The more diﬃcult the decision to
make an announcement is, the more serious the evacuation
information phase becomes. Delays in making evacuation information announcements may occur as a result. It will also
be necessary to perform quantitative analysis on more cases,in order to clarify the factors related to delays. Conducting
a survey with local governments will be important.

Acknowledgment
The data for this investigation were provided by local
governments in Aiso, Ayabe, Fukuchiyama, Hikone, Kyoto,
Omihachiman, Oyamazaki, Uzi, and Yasu.

References[1] Cabinet Oﬃce Government of Japan, “Guidelines for Producing a Decision and Dissemination Manual for Evacuation
Advisories and Orders” , 2005
[2] H. Taubenbock, N. Goseberg, N. Setiadi, G. Lammel, F.
Moder, M. Oczipka, H. Klupfel, R. Wahl, T. Schlurmann,
G. Strunz, J. Birkmann, K. Nagel, F. Siegert, F. Lehmann,
S. Dech, A. Gress, and R. Klein, ““Last-Mile” Preparation
for a Potential Disaster-Interdisciplinary Approach Towards
Tsunami Early Warning and an Evacuation Infomation System for the Coastal City of Panding, Indonesia”, Natural Hazards and Earth System Sciences (NHESS), Vol.9,
pp.1509-1528, 2009[3] L. Gunawan, S. Fitrianie, Z. Yang, W. Brinkman and M.
Neerincx, “TravelThrough: a Participatory-Based Guidance System for Traveling Through Disaster Areas”, Proceedings of CHI’12 Extended Abstracts on Human Factors
in Computing Systems, pp.241-250, 2012[4] H. Watanabe, Y. Narita, K. Oyama, K. Tadashi, A.
Takeuchi and T. Takenaka “Development of Disaster Evacuation System for Finding Shortest Routes with Mobile
Devices”, The Information Processing Society of Japan,
Vol.53, No.7, 2012[5] M. Kodama, T. Kinoshita and T. Katada, “Study on Characteristics of lnhabitams’ Acceptance of Phased Evacuationlnfbnnation”, Japan Society for Disaster Information Studies, Vol.6, pp. 51-60, 2008
[6] H. Yabe, “Study on Providing Evacuation Information
Based on Flood Characteristics”, Japan Society for Nutural
Disaster Science, Vol.19, No.1, pp. 111-120, 2000
[7] T. Katada, M. Kodama and Y. Oikawa, “Study on Resident’s Intention to Acquire Disaster Information in The
Process of The Flood Disaster”, Proc. of JSCE, Vol.786,
pp. 77-88, 2005[8] M. Ushiyama, A. Yoshida and W. Kokubu, “An Analysis ofUnderstanding of Internet Users for Heavy Rainfall Disaster
Information”, Committee on Hydroscience and HydraulicEngineering, Vol.52, pp. 445-450, 2008[9] Y. Ohta and M. Ushiyama, “Problems with the Use of
Heavy Rainfall Disaster Information by Municipality Oﬃces
Based on Questionnaire Survey in 2008”, Japan Society for
Nutural Disaster Science, Vol.30, No.1, pp. 81-91, 2011[10] Japan Meteorological Agency:
http://www.jma.go.jp/jma/indexe.html[11] Central Disaster Management Council, “Examination Subject of Evacuation in Disaster Period -Clarifying View of
Evacuation-” , 2012[12] H. Omer and N. Aion, “The Continuity Principle: A Uniﬁed Approach to Disaster and Trauma”, American Journalof Community Psychology, Vol.22, No.2, pp. 273-287, 1994
[13] K. Yamori, “Revisiting the Concept of Normalcy Bias”,
Japanese Journal of Experimental Social Psychology,
Vol.48, No.2, pp. 137-149, 2009[14] K. Tanaka and T. Kato,“Perceived Danger can be Inﬂuenced by How the Emergency Information is Expressed”,
The Japanese Journal of Cognitive Psychology, Vol.9, No.1,
pp. 1-7, 2011