Journal of Natural Disaster Science, Volume 30, Number 1, 2008, pp13-23

13Bottleneck Analysis of Disaster Risk Communication Problems
Based on Post-disaster Field Surveys--- Case Studies of Two Typhoon Disasters in Japan

Chao ZHANG1, Norio OKADA1, Muneta YOKOMATSU1 and Yoko MATSUDA2
1
Disaster Prevention Research Institute, Kyoto University;
Graduate School of Urban Management Engineering, Kyoto University
2(NPO) Rescue Stockyard, Nagoya(Received for 28 Feb., 2007 and in revised from 19 Sep., 2008)

ABSTRACT
Identifying and overcoming various bottlenecks of disaster risk communication is considered an essential problem for the betterment of disaster early warning and quick response. In this paper, a systematic method of formalizing and analyzing these bottlenecks is proposed. Two typhoon disasters are focused on and field surveys are
conducted. Several conceptual models have been proposed. The C-E-D model can be used to analyze the bottlenecks of information processing within one agent. It can also be extended to analyze inter-organizational information problems among different agents and organizations. To explicitly examine information-sharing devices forthe different agents involved, the proposed hierarchical and sharing model can be used. The three-layer risk communication model associated with the pagoda model helps us position the level of bottlenecks in disaster risk communication. Policy implications are also derived from the proposed approach. Our methodological approach (iffurther improved) will also serve to systematically guide field investigations during and after a particular disaster
if we intend to analyze a diverse spectrum of disaster risk communication problems.

1. INTRODUCTION
Japan is one of the countries severely affected by typhoon disasters. Sometimes, a typhoon will cause huge property loss andhuman injury. To reduce life and economic losses due to typhoon
disasters, the importance of the role of an effective early warning
system and evacuation action is obvious. But from the viewpoint ofcoping with typhoon disasters in recent years in Japan, there appear
to be many issues that need to be addressed to improve early warning information and communication for effective evacuation.
Based on the method of questionnaire investigation, theresearchers have made many findings on early warning and evacuation (Hiroi et al., 2005; Katada et al., 2003; Takeuchi et al., 2006).
In this paper, these issues are examined first from the viewpoint of disaster risk communication. We focus on the communication of risk in the period of disaster early warning and quick
response. By examination and evaluation of various failures or
obstacles in the risk communication system in the real situation andthe various natural, technical, and social factors behind them, conceptual risk communication models are proposed as a framework toformalize and analyze them. In this respect, the uniqueness of thisresearch lies in proposing a framework for discussing (as well as
formalizing and designing) comprehensive post-disaster social surveys. This point is extremely important since to our best knowledge, such a systematic framework has not been well addressed or

proposed. Therefore, it is yet a missing research theme to be
explored, even though there have already been numerous field surveys and investigations conducted for specific disaster-stricken
areas in Japan as well as for other countries.
We also attempt to set up a method to systemize the lessons orbottlenecks of early warning and evacuation actions exercisedunder different real contexts. The proposed approach is intended tohelp us better understand the complex process of disaster early
warning and evacuation action systematically. We also note thatthe findings of this paper are expected to provide a preliminary
basis for designing and conducting both adaptive investigation andfollow-up research by continuous monitoring and verification to be
carried out in the same and in other survey fields.
Case studies have been conducted for two disaster-damaged
fields. One is the northern region of Kyoto Prefecture, which suffered heavy rainfall and flood disaster from Typhoon No. 23 in
October 2004 (Ministry of Land, Infrastructure and Transport
Kinki Regional Development Bureau, 2004). The other is a part of
the Kyushu region, which suffered flood disaster from Typhoon
No. 14 in September 2005 (Cabinet Office Government of Japan,2005). Case studies have been conducted by first analyzing thedata and information available on the official websites of the central and local governments, local newspapers (Kyoto Shinbun;
Miyazaki NichiShinbun), etc. Thereafter, field surveys were conducted by the authors. The locations of the field surveys are shown

KEY WORDS: bottleneck analysis, disaster risk communication, field survey, typhoon disaster, case studies

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C. ZHANG, N. OKADA, M. YOKOMATSU AND Y. MATSUDA

in Fig. 1. The town offices, local households, and some enterprisesin the affected areas were interviewed. For Typhoon No. 23, wevisited the town of Oe Cho (it has now been combined with the cityof Fukuchiyama) in the north of Kyoto Prefecture. A field survey
was conducted on November 29, 2005. For Typhoon No. 14, fieldsurveys were conducted twice in the town of Kitakata Cho and
Hinokage Cho (now amalgamated into Nobeoka City) in the northof Miyazaki Prefecture. The dates of the field survey were
November 10 - 11 (2005) and January 12 - 13 (2006), respectively.
In the field surveys, questions on the following aspects wereasked of the interviewees:(1) The circumstances of information dissemination of early warning and evacuation action(2) The personal risk perception and evacuation behavior of theindividual interviewed(3) Past disaster experience and lessons in the same area
(4) The role played by the local disaster prevention organization in
the evacuation action
2. INVESTIGATION RESULTS REVEALEDFROM THE FIELD SURVEYS
2.1 Basic facts
The basic facts of the two case studies are given in the following table. It is added that the two case study areas (Oe Cho in
Kyoto Pref. and Kitakata Cho in Miyazaki Pref. ) are located very
distant from each other but both have common characteristics. For
example they are similar in the size of population (Oe Cho having
a population of c.a. 5600, and Kitakata Cho, c.a. 5000 as of year2004). The former town (c.a. 200 km2) is twice as large as the latter (c.a. 100 km2) in the area of jurisdiction. Both towns are mountainous communities and suffering from rural decline and excessive aging.
In Japan, there are three natural disaster warning modes disseminated from the town office to the local residents according to
the degree of emergency: voluntary evacuation, advice to evacuate,
and instructions to evacuate. Compared with the case of Oe Cho in
Typhoon No. 23, in the case of Kitakata Cho in Typhoon No. 14,

the local residents who live in a region frequently revisited bytyphoons (such as the 2004 Typhoon 15) tend to have more experience of coping with typhoon disasters and are liable to conduct voluntary evacuation.
2.2 Findings
There are several problems (or bottlenecks) regarding disasterrisk communication revealed from the case studies. They will be
discussed from the following viewpoints:(1) Town office inundated (Source: interviews and newspaper
reports)
Some town offices that were assumed to serve as emergency
management headquarters were inundated during the flood. In thecase of Oe Cho, the room of bousaimusen (a kind of tone-alert
radio system) on the ground floor of the town office building wasinundated. Electric power was shut down. Communication facilities failed to receive related information from other agencies. It
was also impossible to send out an evacuation message to the local
residents. In the case of Kitakata Cho, although the bousaimusensystem installed on the second floor still worked, dissemination ofevacuation instructions was delayed because the facilities of thedisaster information-processing system on the ground floor wereinundated and could not be used to receive and analyze meteorological and hydrological data.
(2) Information-receiving procedure for local residents(Source: interviews)
In the case of Oe Cho, five villages were isolated by the floodor landslide. Roads and electricity were cut off. Hinokage Cho
experienced a similar situation. Three villages were isolated bylandslide. Telecommunications and electric lines connected to theoutside were damaged. The on-site condition could only beobtained on foot. Under these circumstances, usually local residents must depend on their own knowledge and judgment to survive and evacuate. In the survey of Kitakata Cho, the complaint ofsome households of forgetting to put the battery in was found.
In normal periods, some residents took out the battery from thebousaimusen receiver, forgetting to return it during emergency
periods, so they could not receive related disaster information via
this device.

Fig. 1 Location of field surveys
A: Oe Cho (in Kyoto Pref.)
B: Kitakata Cho & Hinokage Cho (inMiyazaki Pref.)BOTTLENECK ANALYSIS OF DISASTER RISK COMMUNICATION PROBLEMS BASED ON POST-DISASTER FIELD SURVEYS

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Table 1 Basic information on the two case studies

Fig. 2 Gaps in risk perception between town office and local residents(3) The understandability of risk information (Source: interviews)
By a field survey, some gaps in risk perception between local
residents and persons of the town office were identified. In the
town office of Kitakata Cho beside the Gokase river, disseminationof early warning and evacuation information from the town office
is conducted via bousaimusen. The content of information is, forexample, Now the runoff from the Hoshiyama dam is xxxx
ton/sec. Please conduct voluntary evacuation, etc. The
Hoshiyama dam is located upstream of the town, as shown in Fig.
2. But our field survey including interviews with local residents
has shown that from the viewpoint of the local residents, this kindof information is considered too technical. From only a message
like this, it is difficult for the local residents to judge to what extent
their home is at risk. So, how the information affects the evacuation behavior of local residents will not be as expected by the town

office. It would be easier for the local residents to understand therisk situation by receiving information disseminated to them like
this: The liquor shop is now flooding. Please evacuate. Here,the liquor shop is located near their home. They are familiar with
it and would prefer to use it as a reference.
(4) Decision to take evacuation action (Source: reports of newspapers and other researchers)
In the case of Oe Cho, although there were different kinds ofevacuation information disseminated from the town office, notmore than just 20 percent of local residents followed the instructions to evacuate. A similar situation happened in the other floodaffected region in Kyoto Prefecture, as shown in Table 2. In addition, through the field survey, local residents were found to choose
the second floor of their house in preference to official designatedschools as shelter.
In the case of Kitakata Cho, the situation was different; most

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Table 2 Percentage of residents under different warning modes in Typhoon No. 23, 2004
(Source: Committee of Typhoon Disaster Prevention in Kyoto Prefecture)

Fig. 3 Communication with agent of the environment

local residents conducted voluntary evacuation to designated shelters. For designated shelters in eleven districts in this town, all 217
refugees adopted voluntary evacuation. Through the field survey,
various factors were found to affect the decision regarding evacuation behavior, as shown through the following narratives frominterviewees:i) I am old, and should evacuate sooner.
ii) Even if the flood enters my room, I can stay on the second
floor temporarily, so I do not need to worry.
iii) Some valuable articles are still on the first floor, and after
taking them up to the second floor, I will evacuate.
The local residents did not usually follow the evacuation
instructions instantly; they usually considered their own situation.
There were many factors affecting their decision.
(5) Information exchange between organizations (Source:
reports of newspapers and other researchers)
There were bottlenecks in this aspect. Here, two examples are
given. In the context of Typhoon No. 23, too much information,
without its priority of importance being considered, was sent out tothe receivers via fax during the period of emergency. This confused the receivers, causing them to spend a lot of time checking.
Another example is where a sightseeing bus was trapped in theflood in Typhoon No. 23. On the road to the destination at night,
this bus was trapped and stopped by the flood from the Yura river.
Thirty-seven passengers had to spend a terrible night on the roof ofthe bus. From this accident, the issue of ineffective information
sharing between traffic and river agencies can be identified.
(6) Designated refugee shelters (Source: the field survey andreports of newspapers)
In the case of Typhoon No. 23, 2004 (in Oe Cho), there werecomplaints about some designated refugee shelters by the local residents that they were inundated, too far away, or the door

had not been opened yet, etc. There were similar circumstances
in Typhoon No. 14. In Hinokage Cho, one primary school specified as an official refugee shelter had not been inundated by theriver under its foot, but over its head, a severe landslide occurred.
The shelter was nearly destroyed.
For the above problems or bottlenecks, it is not enough to only
list and record them in a report; it is necessary to analyze them andset up some kind of theory to formalize them. This kind of theory
would be useful for decision making in the future. For this purpose
we will now turn to conceptualization and modeling.
3. CONCEPTUAL DISASTER RISK COMMUNICATION MODELS
Here, two agent models are proposed for disaster risk communication at the stage of early warning and quick response. One is a
special type: communication with agents of the environment. The
other type is communication with other agents.
3.1 Communication with agents of the environment
Through instinct, as well as common sense and experienceobtained in daily life, human beings are considered to have thecapability to communicate with agents of the environment. As natural hazards happen, through their own observation, past experience, and knowledge, some human beings can make correct judgments, such as which place is in danger and which place is safe andsecure. For this process from information received to action taken,
the so-called C-E-D model can be used to describe it, as shown in
Fig. 3. The C-E-D model was first proposed by Yoshida (1990) to
describe the information process within one agent. Okada (2005)
applied the C-E-D model to the field of disaster information dissemination.

BOTTLENECK ANALYSIS OF DISASTER RISK COMMUNICATION PROBLEMS BASED ON POST-DISASTER FIELD SURVEYS

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Fig. 4 Communication with other agents

Fig. 5 Three key symbols used in modelingFig. 6 Hierarchical model

The agent (here corresponding to the local resident) senses
signals from the environment. Through the process of cognition,
evaluation, and direction (the so-called C-E-D process), the person
makes a decision. In the cognition process, the agent needs to recognize the facts. Then, in the evaluation process, the agent makes
a value judgment. In the process of direction, the agent makes acorresponding decision. For the evaluation that a person (agent)
makes, such as evaluating how severe a condition is and when
he/she must start evacuation, his/her past experience and knowledge gained from routine life play an important role.
3.2 Communication with other agents
Compared with the former case ( communication with theenvironment ), communication with agents is more common.
Here, the agents would be the staff of the town office or the neighbors of local residents, as shown in Fig. 4. In this figure, sinkmeans the destination (recipient) of the information flow being
processed through the agent. This time, the C-E-D process is stillvalid within each agent. The information source of local residents
is not only the direct environment, but also other agents such as the
town office. For example, local residents receive information fromthe town office such as advice to evacuate, combine it with theirown observation of the environment, and judge whether or not toevacuate. Once the decision is made, they will go to a safe place,such as an officially designated shelter. This kind of information
flow between the town office and local residents is obviously notunidirectional. Sometimes, local residents will give some usefulon-site information to the town office.
3.3 Information flow between different agents
As far as the actual context of the risk communication process

Fig. 7 Sharing model

is concerned, not only various spatial and temporal factors but also
the characteristics of the behavior of agents need to be considered.
In order to promote participation in terms of information, knowledge, and action sharing, two organizational patterns of disasterrisk communication can be identified. They can be generalized as
the hierarchical model and the sharing model, respectively. The
former can be applied to early warning and quick response retroactive situations, especially command and control situations. The latter can be applied to collaborative and collection situations.
In order to denote these models figuratively, three basic elements are introduced here as shown in Fig. 5. They are node,
directed arc, and loop, denoting agent, information flow, and information sharing, respectively.
(1) Hierarchical model
In this case, the information flow is commonly one way.
Graph (a) in Fig. 6 gives its basic form, and in actual situations,complex variations of it can be observed, as Graphs (b) and (c) in
Fig. 6 show. Information flows among administrative agencies areillustrated by these graphs. The dissemination of meteorologicalinformation from the meteorological agency to related governmental agencies is illustrated by Graph (b). Disaster-related information received by the town office from different sources is illustrated
by Graph (c). Here A, B, C in Figs. 6 and 7 exemplify any possible three agents (administrative agencies) symbolically modeled as
nodes.
(2) Sharing model
As Fig. 7 shows, here, related agents share their information.
The loop serves as an information platform. Information flows
from different sources are integrated and properly matched on thisplatform. In the context of early warning and evacuation, twotypes of sharing model can be identified. One is the external

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dependent type. The information-broadcasting system on the platform of the Internet illustrates this type. It serves as a common
platform to provide external dependent information to the public.
The other is the self-reliance type. In the context of community,
the evacuation behavior of local residents can be described by thisgraph. Local residents mutually exchange information or knowledge received from the mass media or related NGOs. Their decision is then made.
4. BOTTLENECK ANALYSIS
Case 1: Town office inundated. The town office lost the capability to receive and disseminate information. Because of inundation, its facilities were physically damaged. Its headquarter functions were paralyzed. Communication between the town office andlocal residents was blocked. The positions at which bottlenecks
occurred are illustrated in Fig. 8 (a).
Case 2: Isolation of the local community. Here, three types ofisolation can be identified. One type is physical isolation, whichmeans that the community is not physically accessible. Lifelines
and roads were shut off from the outside. The second type is communicative isolation. Communication bottlenecks between residents and the town office were one-way or two-way. A one-way
bottleneck was where some households could receive information
by bousaimusen, but it was difficult for them to send out information to let the town office know that they were isolated. This is
illustrated in Fig. 8 (b). A two-way bottleneck was where households were totally isolated from the outside. They could neither
receive information from the outside, nor send out information tothe outside for help. The third type is transportation and lifeline

supply isolation. In this case, although there was no problem withthe communication of the local community with the outside, transportation and lifeline supply were still not functional. Food supply
still depended on the outside by helicopter.
Case 3: The contents of bousaimusen. From the message,
Now the runoff from the Hoshiyama dam is xxxx ton/sec. Please
conduct voluntary evacuation, it was difficult for the local residents to evaluate the risk situation. A decision on whether or notevacuation should begin could not be made. As Fig. 8 (c) shows,
this time in the information process of C-E-D, a bottleneckoccurred in the process of E, so the process of D after thatwas not active.
Case 4: Problem of self-judgment. Through field surveys,
some local residents were found to take action depending more on
their own judgment. For them, the messages from the town office
were only one information source for reference. In this case, if thisjudgment comes from past disaster experience, it is reasonable.
But if it only comes from self-confidence or taking certain circumstances for granted, it is very dangerous. Bottlenecks could happen
in any process of C-E-D, as shown in Fig. 8 (d). The following
three cases, as examples, have been identified from the field surveys.
Local residents may recognize the facts through observation.
But sometimes, the scope limitation of their information acquisition and past experience will prevent local residents from making
correct factual judgments. So, a bottleneck will occur in theprocess of C.
Priority is another factor that needs to be pointed out. It isnecessary to evacuate to a safe place for people s lives, but theirproperty is also important. When they decide to adopt a certain

Fig. 8 Various bottlenecks in disaster risk communication

BOTTLENECK ANALYSIS OF DISASTER RISK COMMUNICATION PROBLEMS BASED ON POST-DISASTER FIELD SURVEYS

action, they must strike a balance between them. It is one pointthat needs to be considered not only by local residents, but also byenterprises. This is one of the differences between a flood and anearthquake which is also a common hazard in Japan although it is
not discussed in this paper. In a flood, people still have some time
to take action. In this case, bottlenecks will happen in the processof E. If their evaluation is not correct, the wrong decision is theninevitably made.
Incidentally, people with disabilities or elderly people cannot
take action themselves easily for immediate evacuation. In the disaster of Typhoon No. 23, among the 96 persons killed, there were
54 persons over 65 years old (Ushiyama, 2005). Although theymight have heard the warning message, they would have been
unable to make a quick evacuation by themselves. In this situation,
the bottleneck can be categorized as happening in the process ofD.
Case 5: Information exchange among agencies. Here agencies
mean government agencies such as main and branch offices of different level of local governments which are responsible for information exchange for disaster management. As far as the fax problem is concerned, the bottleneck can be ascribed to the one-directional information flow. There is one weakness in sending messages only via fax, as it is not guaranteed that the message will bereceived in time and understood completely by the receiver. In
addition, staff (in a particular agency) who receive a large numberof fax sheets from related agencies are sometimes unclear as towhich is more important than the others. The multiple (and nonclassified) contents of the fax confused the recipients (Okada,2005). In the accident of the sightseeing bus, the bottleneck can be
ascribed to the lack of an information-sharing system. To solve
this problem, only depending on information from one or two
agents is insufficient.
Case 6: Designated shelters. Official specified shelters are
assumed to be safe enough for one kind of disaster, but sometimes
face high risk in other kinds of disaster. The reason for this is lackof sufficient knowledge of the local community.
5. FORMALIZATION OF BOTTLENECKS
5.1 Types of disaster risk communication bottleneck
From the above analysis, for disaster risk communication at
the stage of early warning and evacuation, two types of bottleneck19

can be identified, as shown in Fig. 9. Here, each triangle represents each agent, and intra-agent information processing isassumed to be conducted within each triangle (the upper or lowerone) as represented by its respective horizontal row. One type ofbottleneck (symbolized by small black triangle blocks within therow) is called an inter-agent bottleneck, and the other is an intraagent bottleneck (symbolized by small black triangle blocks
between Agent i and j). Inter-agent bottlenecks occur when two
agents engage in communication between different organizations.
Intra-agent bottlenecks happen in the C-E-D process within eachagent.
5.2 Three-layer disaster risk communication agent model
In order to better understand disaster risk communication bottlenecks, from the viewpoint of integrated disaster risk management, especially considering the activities conducted by the agent
who is positioned in a city or region, a three-layer conceptual disaster risk communication agent model is proposed, as shown in
Fig. 10. The agent model (right-hand triangle) shows that eachagent conducts activities based on the regional/social system. Thisregional/social system can also be modeled as our common temporal/spatial system as represented by the pagoda model (left-handtriangle) first proposed by Okada (2000).
Let us first look at the agent model. From the bottom up, thefirst layer (OL) is the organizational layer to which agents are related. It represents the organizational structure and framework thatgoverns information flow among the same and/or different organizations (governmental and non-governmental agencies and local
residents in the neighborhood community). The second layer (CL)is the cognitive layer. It addresses the risk perception characteristics of different cognitive agents such as local residents and government agencies. The top layer (AL) is the action layer. It is concerned with actions (which may interpretatively include revealed
behaviors) taken by different agents as a result of the informationprocessing process structured by the above-explained C-E-D prototype model. In other words, the second and third (top) layers correspond to the C-E-D prototype model, and the first layer is considered to refer to the relevant organizational framework that provides
a platform for information processing by related agents.
Importantly, a fundamental set of the three-layer subsystemneeds to be positioned in a common spatial/temporal setting that
we call the regional/social system. For instance, the developmentlevels of infrastructural facilities in the regional/social system

Fig. 9 Intra- and Inter-agent bottlenecks

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C. ZHANG, N. OKADA, M. YOKOMATSU AND Y. MATSUDA

together set the conditions for the three-layer subsystem to makeearly warning and evacuation messages accessible and useful tothose responsible for this task as well as potential end-victims(local residents, schools, hospitals, companies, etc.) We propose to
apply Okada s pagoda model to systematically characterize theregional/social systems. The large pyramid picture on the left in
Fig. 10 illustrates the pagoda system. The top level of this pagoda
model, which refers to life in the community, is interpreted ascorresponding to the three-layer system. (See the small pyramid on
the right in Fig. 10.) This perspective may also be used to position
the levels of disaster risk communication bottlenecks.
This layer may be the most complicated, and concerns thekinds of physical, social, or psychological factors that determine
whether or not a person adopts the correct action in a disasteremergency. The above three layers are based on a specified
regional and social system. The roles played by these layers in disaster risk communication during emergency and quick response
periods are highly dependent on the characteristics of this regional/social system. Okada (2004) set up a theoretical model (pagoda
model) to describe it, and regards it as a five-story vital system.
Basically, the top-level layer (LC) in the pagoda model corresponds to the action, cognitive, and organizational layers in theagent model. The layers (LB) to (NE) in the pagoda model correspond to the regional/social system in the agent model. These relationships between the three-layer disaster risk communication
model and the pagoda model are shown by the dotted lines in Fig.
10. These models can be used together to classify different disasterrisk communication bottlenecks positioned in spatial/temporal systems.
In fact, bottlenecks of disaster risk communication in the realworld can occur from different aspects. According to the above
conceptual model, the different bottlenecks analyzed in Section 4
are classified in Table 3.
6. POLICY ANALYSES
Next, some of the conceptual models proposed above will be

used to discuss solutions to various risk communication bottlenecks regarding the early warning and evacuation mentioned in
Chapter 4. Table 3 is also used for this purpose.
6.1 Basic policy issues as a complementary discussion(1) Layer (I)-(LB)-AL policy issues: An example of preventing
the town office from being inundated (Case 1 in Table 3)
These policy issues are basically concerned with aspects ofLayer (I)-(LB)-AL, all of which are defined as somewhat physical,
location specific, and actionable. So a set of countermeasures may
well be selected from this category.
As the center of disaster information receiving and dissemination, the town office plays an important role. Its disaster prevention capability is vital for the whole system of disaster early warning and quick response. Its location should be far from flood-prone
areas. If possible, the disaster prevention facility should be backed
up. For flood-vulnerable town offices, relocation or setting up atemporary center in the flood season would be an alternative solution. To avoid information cut off in a remote town from the outside, a corresponding wireless or satellite communication systemshould be set up in the local municipal office (or assumed alternative headquarter building) .
(2) Layer CL policy issues: An example of producing andsending readily comprehensible messages through bousaimusen to the public (Case 3 in Table 3)
These policy issues are basically concerned with aspects ofLayer CL, which is non-physical and totally cognitive.
So that local residents clearly understand the information frombousaimusen, it is necessary to avoid using too many technicalterms. Concerning the effectiveness of early warning, the numberof broadcasts should be controlled. A standard for different evacuation modes should be set up.
(3) Issues of cooperation among agencies
Let us take the example of Case 5 in Table 3. This is the
problem of faxed messages confusingly neglected caused bysimultaneously transferring various kinds of information via fax. It
is categorized as an inter-agent problem relevant to CL (cognitiveFig. 10 Three-layer disaster risk communication agent model corresponding to life in the community in the pagoda model by Okada (2004)

BOTTLENECK ANALYSIS OF DISASTER RISK COMMUNICATION PROBLEMS BASED ON POST-DISASTER FIELD SURVEYS

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Table 3 Bottleneck taxonomy of different cases

Fig. 11 Some countermeasures against bottlenecks

level). Although it looks relatively simple, definitions have to be
examined in a comprehensive manner. Application of Fig. 11 may
well serve this purpose.
To solve the problem of faxed messages confusingly neglected, a certain feedback mechanism should be set up, as Graph (1)in Fig. 11 shows. Although it may not always be necessary,
upgrading the reliability of the whole communication system will
be very effective. It is necessary to set up some kind of feedback
mechanism from local residents to the town office in the early
warning system. For the communication network, multi-routes arenecessary. When disasters occur, some communication routes thatwork well in normal times are found to fail. So, in this context,
improvisatory management should be conducted. Temporaryroutes of communication should be set up or used as a tentative
method of transferring information, as shown by Graph (2) in Fig.
11. This kind of temporary (and contingent) management should
be involved in routine disaster training programs.
To avoid the accident of the sightseeing bus mentioned above,a platform of information sharing is needed. On this platform,
related real-time information from different agencies can bebrowsed and modified, and can be utilized by other agencies, as
shown by Graph (3) in Fig. 11.
(4) Issues of participation
Related to the issues of cooperation, we need to discuss issuesof participation. A good example is a combination of Cases 4 and
6 (and quite likely also Cases 1, 2, and 3 in Table 3). In the issueof shelters, whether a shelter is safe or not should not be determined only by one agent, e.g., the town office. Participatory risk
communication is needed among government, NGOs, and local
residents. After all, local residents are the victims of natural disasters. Their capability of risk perception of natural disasters shouldbe improved under the help of government and NGOs. So, in normal times, residents, governments, and NGOs should work together, strengthening participatory risk communication among them.
Overcoming the bottleneck of self-judgment depends on disastereducation through disaster participation activities among local residents, government, and NGOs.
(5) Issues of span of time
The bottleneck of disaster risk communication needs to be
examined not only from the viewpoint of agents or organizational

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structure, but also from the temporal aspect, that is, span of time.
This viewpoint is sometimes easily omitted, but is in fact very
important, considering the disaster management cycle. There are
two stages to be focused on along the time axis as shown in Fig.
12. Here, Time 1 denotes the period from the moment at whicha hazard is observed to happen to the moment at which the residents manage to find a safe place. Time 2 denotes the long period until a hazard happens again. Katada et al. (2003) noted that for
local residents, evacuation and action to protect household goods
against inundation arise from the recognition that it is a time ofcalamity. And these actions have a tendency to be suspended until
the recognition becomes certain. This process of recognition basedon gathering disaster information corresponds to Time 1 here.
For floods, Time 1 is very limited, especially for flash floods.
The decision to evacuate must be made within a limited span oftime. But a flood sometimes comes very quickly, and people haveno time to respond. From this viewpoint, Time 1 can be regarded as a special kind of bottleneck in disaster risk communication.
In addition, it is unreasonable to regard Time 2 as unlimited.
So, in normal times, residents, governments, and NGOs should
hurry, work together, and strengthen participatory risk communication among them. Otherwise, when disaster strikes, early warning
will be found not to work. Okada and Matsuda (2005) proposed arisk communication strategy for community-based disaster preparedness. Without this successful communication process in routine life, it is difficult to achieve the goal of eliminating various
bottlenecks in disaster risk communication in the process of early
warning and evacuation.
6.2 Limiting factors for overall policy assessment
If the above basic proposals are examined in the context of
concrete communities, some limiting factors related to localities
will be found. This paper has shown this only in the limited contexts of the study areas selected. Moreover for overall policy
assessment, there are many other factors to be examined such as
economic costs, aging society, fewer young people in rural areas,interest conflict between different social groups, land use policy,
etc. They can appear at different levels in the pagoda model.
These factors will adversely affect an effective solution to various
disaster risk communication bottlenecks being found. If various
disaster risk communication bottlenecks are likened to the leaves ofa tree, these limiting factors would then be the roots. How to eliminate them is the task not only of disaster prevention managers, butalso of regional development planners. This leads us to our claimthat a more integrated disaster risk management is needed.
7. CONCLUSIONS
The various bottlenecks of disaster risk communication are
significant problems in disaster early warning and quick response.
In this paper, a systematic method of formalizing and analyzingthese bottlenecks is proposed. For this purpose, several conceptualmodels are presented. The C-E-D model can be used to analyze
bottlenecks of information processing within one agent. Its application can be extended to analyze inter-agent information problems
among different agents and organizations. To explicitly examine
information-sharing devices of the different agents involved, theproposed hierarchical and sharing model can be used. The threelayer risk communication model associated with the pagoda model
helps us position the level of bottlenecks in disaster risk communication. In this way, we can closely examine the whole picture ofbottlenecks from the viewpoint of integrated risk management.
Policy implications may also be effectively derived from thisapproach. Our methodological approach to proposing a framework(if further improved) will serve to systematically guide field investigations during and after a particular disaster if we intend to analyze, evaluate, and solve a diverse spectrum of integrated disasterrisk management issues, particularly focusing on disaster risk communication problems.
Of course, the current study has limitations and further examination needs to be conducted. Admittedly, more extensive investigation should be carried out to follow up on the tentatively foundresults and implications. In the same fields as well as other fields,
adaptive research should be further conducted. Continuous monitoring and verification are essential to improving the applicabilityof our approach. In fact, we are now conducting a similar study tosystematically analyze two recent flood disasters in China.
Additionally, continuing work will be performed in the same area
in Japan and continuous monitoring conducted to examine the viability of the formalized knowledge and models.

Fig. 12 Limited span of time − another kind of bottleneck

BOTTLENECK ANALYSIS OF DISASTER RISK COMMUNICATION PROBLEMS BASED ON POST-DISASTER FIELD SURVEYSACKNOWLEDGEMENTS
This study was supported by the Japanese Ministry of
Education, Culture, Sports, Science and Technology 21st COE
Program, awarded to the DPRI, Kyoto University. We would liketo thank Dr. Yukiko Takeuchi and students of the Research Center
for Disaster Reduction Systems, Disaster Prevention ResearchInstitute, Kyoto University for their kind advice and help.
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