- 総合都市研究 (ISSN:03863506)
- no.37, pp.p169-192, 1989-09
1987年12月17日に発生した千葉県東方沖地震での市町村の対応に関し、市町村の防災担当者らを対象にアンケート調査をおこなった。市町村の震度と地震後の対応について検討した結果、震度が低く測定され住家等の被害が少なくても、組織的な対応をおこなった市町村と、震度、被害ともに大きくても組織的対応をおこなわなかった市町村が存在した。災害対策本部の設置、避難勧告、応急給水活動などの対応は、おおむね震度4.5以上(気象庁震度V)で始まっており、地域防災計画等で計画化されている対応の基準とほぼ調和した。地震直後の被害情報の収集は多くの市町村でおこなわれたが、報道機関や県庁からが多く、近隣住民からの情報収集が少なかった結果、被害状況の把握に長時間を要した市町村が存在した。また住民への地震情報の伝達は、震度に関わらず沿岸部の市町村で活発におこなわれ、津波に対する警戒を目的としたものであった。市町村の対応で、長時間にわたりおこなわれたのは、ガス施設の復旧作業や今回の被害で特徴的であった、屋根瓦の被損した住家へのビニールシートなどの貸出しなどであった。Generally, disaster preperedness plans of municipality are supposed to that operate emergency countermesures in a case of earthquake with a seismic intencity V (I_JMA = 5, MSK;7^+ ~ 9^—) announced by neighboring observatory. However, the intensity of V has wide range from sligtly to rather severe damages. In addition, distributions of ovserbatory are not sufficient as compared with number of municipality which has not observatory in the jurisdiction, the person in charge of disaster prevention is apt to confuse to judge the seismic intensity of his region. Even if such the municipality which has observatory, there is difficult problem how he performs emergency operations and/or decides the extent of them. The 1987 CHIBAKEN TOHO-OKI Earthquake subjected moderate damage as result, and so post-earthquake countermesures of municipalities where implemented variously. The object of this study ; 1) estimating the proper seismic intensity of each municipality ; 2) inspecting and considering the actual response of all municipalities with the seismic intensities at their sites in Chiba prefecture ; 3) proporsing how to make the decision of optimum emergency countermesures for such a critical earthquake in future. The results of this investigation can be summarized as follows. 1) The relationship among the seismic intensities and various damages in each municipality as follows : Casualties and damage of houses occured in some municipalities where were estimated the intensity above 4.2. At the intensities above 5.0, the number of municipalities in which occured the damage of human, dwelling houses, public facilities (including life-line systems) and so on. increased remarkably. 2) Setting up the disaster countermeasure headquarters which is the 1st step of emergency operations by municipality goverment were begun at the intensities above 4.5, moreover, it became remarkably at above 4.8. But, there were some municipalities which did not set up the headquarters, nevertheless their seismic intensities were estimated more than 5.0. 3) Municipal response, such as the orders for evacuation to the residents for preventing to casualties due to landslides, were recognized at the intensity above 4.5. and the response, such as temporary water supply and rending many waterproof shirts to dwelling houses which damaged to their roofs, impremented in the areas of above 4.2, moreover, aforementioned operations incresed remarkably above 4.5. 4) Various kind of disaster information activities to the inhabitants were more quickly and actively carried out in the coastal municipalities than the hinter areas in the case of the same seismic intensities. Because, the former areas have the dangerous tsunami potentials and the various communication system for them.