- 東京大学地震研究所彙報 (ISSN:00408972)
- vol.58, no.1, pp.p207-242, 1983
- 2 or 0
北海道浦河町および浜中町で,津波予報に対する自治体や住民の対応行動の実態を明らかにするため,防災担当者からの実情聴取,住民へのアンケート調査を実施した.昭和57年3月浦河沖地震で,地震災害を受けた浦河町では,地震に対する処理で津波が念頭になかった人が約16%あり,また停電によって情報を得るのに大へん困った人も9.7%という結果が出た.また過去に大きな津波によって,家屋に被災した体験者が過半を占める浜中町では,津波に対する不安感が強く,津波防災意識が高いことがアンケート結果にあらわれている.避難に要する最少限度の時間は,数分乃至10分という結果で,これは津波が100~200m水深の地点から海岸へ到達する時間に見合っている.警報下の船舶の取扱いについては,船のトン数によってかなりはっきりわかれ,小舟は陸へ上げ,大きい船は港外へ避難するという結果が得られている.津波警報は船舶関係老を含めて一般に十分信用して受入れられ,たとえ小津波でも発令することが支持されている.しかし一面では従来の体験をふまえて,各自の判断を加えて行動する自助の意識も強くあらわれている結果となった.In order to investigate the social responses to the tsunami warnings, we conducted letter questionnaires in the towns of Urakawa and Hamanaka in Hokkaido and interviewed officials of the local administrative organs. The results of the questionnaires are as given below. In Urakawa, which was damaged by the 1982 Urakawa-Oki earthquake, about 16 percent of the respondents were so busy settling their damaged houses and furniture that they could not be concerned about the danger of the tsunami. A total of 9.7 percent of the people did not get the news owing to an electrical failure. These results suggest that should a great tsunami immediately follow an earthquake, it might hit the community inhabitants before they can take refuge on the hilltops. In Hamanaka, the majority of the people replied that their houses had suffered some damage from the great tsunamis in the past, while in Urakawa only one percent of the respondents mentioned this. So the people of Hamanaka felt more uneasy about being hit by the tsunami and were more eager about tsunami disaster prevention. But as for the tsunami warnings, the residents of both towns trust them and hope that the Meteorological Agency announces tsunami predictions even though their scale is estimated to be small. They also desire proper measures to make warnings more useful to the local residents. The respondents replied that it takes them five to ten minutes to arrive at the refuge. This is about the same amount of time it takes a tsunami to reach the shore from a point 100 to 200 meters deep after the earthquake occurs. Therefore, it is suggested that if a tsunami off the shore is observed with the tele-meter, we can know in advance when it will hit the shore and quickly work out some countermeasure for it. There are two ways to deal with ships when the tsunami warnings are issued; ships less than 3 tons will be beached, and larger ships will leave the harbor. Our surveys make the fact clear that the inhabitants in general behave properly based on tsunami warnings and their past tsunami experiences.