When landslides occur in snow-covered areas, the presence of snow may cause a secondary hazard. In the Tatsunokuchi area of Tsunan-machi, Niigata Prefecture, Japan, a large landslide was induced by the seismic motion resulting from the North Nagano Prefecture earthquake (magnitude of 6.7) on March 12, 2011, which caused a snow avalanche at the same time. In this study, a ground penetrating radar (GPR) survey was applied to find areas of buried snow and ice underground in the landslide area. We first conducted experimental field surveys of artificially buried snow and ice to verify the effectiveness of the GPR survey in terms of investigating ice and snow within collapsed land. The results of the experiments successfully detected strong radar reflections from areas of ice and snow. When the ice and snow began to melt, the survey data showed both multiple reflections and the attenuation of reflections by meltwater. Then, we investigated the presence of buried snow in the landslide area of Tatsunokuchi using GPR surveys. A GPR survey conducted in August 2011, five months after the landslide event, showed a clear response indicating the presence of a snowpack underlying the sediment. A response related to an underground snowpack was also observed in November 2012, about one year after the first GPR study. An excavation was conducted and the underground snowpack was ascertained. The snowpack was found to be compressed into an ice-like state that may be appropriate for long-term storage underground. The survey results of the buried snowpack in the landslide area at Tatsunokuchi were consistent with the results of the experimental surveys. Snowmelt water may cause the ground to loosen, which can increase the risk of secondary hazards such as subsidence and sediment discharge by heavy rains. The results of our study indicate that GPR surveys are useful for examining buried snowpacks in landslide areas, as well identifying the potential areas where secondary hazards can be caused by the melting of snow and ice within the landslide area.

抄録全体を表示

This article proposes a multi-agent simulation model to examine how different operational environments and incentive mechanisms affect the collective performance of complex humanitarian response systems. Using the UN Humanitarian Response Depot (UNHRD) system as an example, a stylized model of one service provider, two member organizations and multiple humanitarian crises is developed to illustrate the changing uses of four alternative relief goods sourcing options, namely: i) own storage for own items ii) UN storage for own items iii) stock-swaps and iv) white stock uses. Under the plausible assumption that the past success of sourcing options influences member organizations’ future resource allocation, the model indicates that the additional buffer stock capacity offered by horizontal cooperation induces undesirable system dependency: while it gives member organizations more flexibility to meet highly stochastic demands under uncertainty, it also encourages them to store less of their own relief goods as a result. This tendency was particularly notable under a flexible budgeting regime, highlighting the further need to understand and evaluate the details of the decision-making heuristics of individual member organizations.

抄録全体を表示

Relief supplies stored at shelters may be the only available supplies if shelters become temporarily isolated and inaccessible from outside after a disaster. These supplies become absolutely essential and thus the types and quantities require careful consideration, especially in places that are at high risk of becoming isolated. This issue becomes even more important when vulnerable people are in the isolated shelters. It is a duty of society to take care of victims of disaster. On the other hand, when the number of evacuees in the isolated shelter is more than expected or when the isolation period is extended, a proper management plan is required. The plan should consider how the other shelters and/or municipalities can help when a municipality has lost its functionality after a disaster. It seems that collaboration between municipalities on a small scale operated well during the aftermath of the 2011 Great East Japan Earthquake; however, there is still a need to extend the scale to cover the entire country to increase the efficiency. This paper provides a discussion of the above issues based on current Japanese practice, which can be adapted to other countries as well.

抄録全体を表示

Food security has become increasingly discussed as a matter of concern in some developed countries, including Japan. Immediately after the Great East Japan Earthquake, many people had to spend several days without any food and water due to the slow delivery. This delay can be interpreted as a failure of the food security policy in Japan. In order to meet the needs of the times, the food security policy should be changing like in Britain and other Western countries. Japan realized this fact after the failure of the Great East Japan Earthquake at last, and recognized the importance of humanitarian logistics. However, the most difficult part of humanitarian logistics is the local “last mile.” It is still unknown whether food assistance could reach remote rural areas smoothly. We studied Typhoon Haiyan as a case study of this “last mile” problem. The results confirmed that there was severe food and water shortage immediately after the typhoon struck, but at the same time, the results indicated the resilience of rural areas. These findings can serve as useful basic information for further food security in Japan and other countries.

抄録全体を表示