In cases where a disaster involving an area of a prefecture has occurred, when a municipality is unable to perform all or the majority of its affairs because of the occurrence of the disaster, the prefectural governor must implement on behalf of the mayor of a municipality all or a part of the emergency measures to be implemented by the mayor of a municipality pursuant to the provisions of Article 63, paragraph (1), Article 64, paragraphs (1) and (2), and Article 65, paragraph (1).
When the prefectural governor has begun or completed the implementation of affairs on behalf of the mayor of a municipality pursuant to the provisions of the preceding paragraph, the governor must make a public notice to that effect.
都道府県知事は、前項の規定により市町村長の事務の代行を開始し、又は終了したときは、その旨を公示しなければならない。
Necessary matters related to the prefectural governor in acting on behalf of the mayor of a municipality under paragraph (1) are prescribed by Cabinet Order.
第一項の規定による都道府県知事の代行に関し必要な事項は、政令で定める。
Read this with the articles around it
disastermachine translation
「災害」
Damage caused by a storm, tornado, heavy rain or snow, flood, slope failure, debris flow, storm surge, earthquake, tsunami, soil liquefaction, volcanic eruption, landslide or other abnormal natural phenomenon, or by a large fire or explosion or another cause that a Cabinet Order (政令) specifies as causing damage on a similar scale.
Defined inArticle 2, paragraph (1), item (i)· applies throughout the law
emergency measures
「応急措置」
Fire-fighting, flood fighting, rescue and other emergency measures needed to fend off a disaster or stop it from spreading.
Short name set inArticle 62, paragraph (1)