The continued increase in rain-impermeable regions and extremely local severe rains encourage inland flooding resulting from rain runoff that exceeds rain drainage capability of cities in urban areas. Using the questionnaire survey method, this study revealed aspects of the interest and cognitive structure of residents related to urban flooding, and reliance upon administrative authorities. Administrative authorities are expected to provide public measures for relief of urban flood risk and damage. Nevertheless, self-help by residents themselves is also necessary. Therefore, this empirical analysis was conducted to explore normal factors for the promotion of self-help using covariance structure analysis. Results suggest that a series of constructive concepts by which promoting information about urban flooding raises the consciousness of residents in preparation for flood damage, enhances their independent disaster prevention behavior, and encourages self-help action.

In case of immense disaster, a variety of information is complicated, and makes related organizations impossible to own the right information jointly. Consequently, necessary actions will be delayed, and anxiety of people will increase. In order to solve this problem, a certain social model is proposed, as a method of gathering and delivering information at the disaster. The characteristic of the social model is that plural information systems and communication media are connected, and cooperate to each other, to help many related organizations to collaborate in coping with disaster.

The proposed system is composed of the followings. (1) Information gathering system, with which residents are familiar in usual time. (2) Establishment of “Disaster Information Center” for arrangement/transmission of the information, and participation of regional volunteers as a coordinator. (3) Cross-media communication using multi-communication media. (4) Wide-use information format to connect a variety of dispersion systems.

The system was applied to Fujisawa City, Kanagawa prefecture, and an experiment was conducted to proof the effectiveness of the system. It was pointed out that the information contributed to the system, with which the residents has become familiar, is likely to be trusted, and that the careful consideration was observed by coordinator from regional volunteer, in dealing with regional information at the “Disaster Information Center”. From these results, the system was considered to be effective.

An interview was conducted with “FM Pikkara”, Community FM Broadcasting Station of Kashiwazaki City, which had taken a role of gathering and delivery of information towards residents at the “The Niigataken Chuetsu-oki Earthquake in 2007”. The system proposed was very much encouraged by suggesting the possibility of realization, from the actual use point of view.

Recently, information of heavy rainfall disaster such as providing of warning of landslide disaster and changed easy names of water level of a river was expanded. However, it is feared that a lot of disaster information is not necessarily used effectively in municipalities and inhabitants because they are provided many times by authorities at the disaster and municipalities may not be able to treat all of them.

In this study, the questionnaire survey about the use of disaster information etc. in the heavy rain disaster by Typhoon No. 0709 was carried out to officials of municipalities. Moreover, residents were asked about understanding of disaster information. Then, problems about the use of disaster information were clarified and the ideal way of the effective use of disaster information was examined.

In this study, the survey of inhabitants' consciousness in Nemuro-city which was damaged by Bomb-Low from the 31st of March to the 1st of April in 2008 was conducted, the determination process of inhabitants' risk consciousness were analyzed. As a result, the things that many inhabitants hearing weather forecast were careful with the motion of the atmospheric low, however more than half of inhabitants didn't expect such a damage in spite of the weather forecast, were found out. The more the inhabitant recognized a crisis, the more they measured against a storm, so the importance that the expression of disaster information in order to remind the occurrence of damage before an approach of bomb-low was shown.

Japan Meteorological Agency (JMA) uses not the specific name such as “bomb-low” but the expression of “rapidly developed atmospheric low” or “atmospheric low accompanied violent wind” as the way to express a developed atmospheric low. The problems that the expression of “rapidly developed atmospheric low” had some effects of raising the inhabitants' risk consciousness, however inhabitants didn't remind of the occurrence of damage without the specific explanation for windstorm and snowfall were clarified.

We pointed out the effectiveness of (1) the use of specific name such as “bomb-low” according to development of atmospheric low, (2) the specific description of a windstorm and a snowfall, (3) phasing a development of atmospheric low and a weather warning.

Recently, in Japan, we promote the measures for tsunami as we keep local tsunami with strong shock in mind. But the measures for distant tsunami with weak or no shock are not enough. In such situation, the earthquake of the Chishima Islands occurred on November, 2006, and tsunami warning was issued. In this earthquake, there are many issues like distant tsunami. In correspondence of administrations, 1) the prior measures for tsunami are not enough in the areas that have't experienced a tsunami till now, 2) whether the prior measures for tsunami are carried out or not influence correspondence of inhabitants. In correspondence of inhabitants, 1) the evacuation rate of inhabitants was low in the areas that have experienced tsunami and was high in the areas that have't experienced tsunami till now, 2) these causes ware the size of shock of earthquake and the experience that tsunami didn't hit in spite of the issue of tsunami warning, 3) the evacuation rate of inhabitants fell remarkably by only once experience of false alarm of tsunami.

In this paper, we pointed out that promotion of disaster preventions for tsunami of the areas that they are not enough till now and promotion of the prior measures for disaster preventions for tsunami ware necessary, and improvement of inhabitant's tsunami information literacy that was higher than the literacy of local tsunami was necessary.

The purpose of this study is analysis of relationship between altitude perception and tsunami risk perception on past tsunami disaster area based on questionary survey. The survey was performed in Rikuzenatkata City, Iwate prefecture, and 521 residents completed the questionnaire form. 16.5% of respondents knew the altitude of their house correctly ("Correct"), on the other hand, 46.3% was no answer ("NA"). 13.2% of respondents knew more highly than the correct altitude of their house ("High"), and 24.0% knew more low than it ("Low"). "Correct" and "Low" thought that the place was more dangerous for tsunami disaster than "High" and "NA". In addition, "Correct" and "Low" had positive intention of evacuating for tsunami disaster. It is possible that tsunami risk perception of their residence area has a connection with perception of altitude. It is important to support that residents understand altitude of their residence area.

The paper discussed the Toga-gawa river disaster in Kobe on July 28, 2008. The disaster killed five people, who were at the river side garden, due to an abrupt rising of the river water. Both heavy rainfall and a geographical peculiarity of the river, characterized by a very steep bank slope, caused the disaster. The authors' field survey found that a river space, sandwiched by high river banks, is difficult to escape, and that a disaster site is more than 200 meters away from the closest stairs to escape up to a bank top. An interview with those concerned showed the three social characteristics of a local community around the river should be taken into consideration when analyzing the cause of the disaster, a history of the Great Hanshin Flood and a series of river reconstructions after the flood, the activities of a residents' group for better river environment, and the impact of the great Kobe Earthquake in 1995. It was suggested that the disaster should be examined from the viewpoint of a conflict between “society” and “nature” of the river space, and that risk communication to share small incidents prior to a major disaster is vital.

Both of historically and recently, assistance to affected countries and regions suffered from catastrophic natural disasters and complex emergencies are required severely. A large variety of actors engage in assistance. In order to coordinate a number of actors and facilitate information-sharing among them, assistance demands a certain type of mechanism. Considering these situations, an institution for coordination and information-sharing after natural and man-made disasters, called “Cluster Approach”, adopted in 2005. Cluster Approach is organized by the United Nations mainly. This institution was not constructed suddenly, but some institutions and organizations-settings have already been existed and these have been changed and developed gradually. Contrary to these international backgrounds, and in spite of the importance of information-sharing in international humanitarian emergency relief, it is hard to see related previous researches in Japanese academic areas. Therefore, this article aims to clarify how institutions have been changed and developed historically. Achieving the aim, this article reviews secondary materials and previous surveys regarding information-sharing institutions organized by the United Nations.