disaster occurrence; outbreak of a disaster
Refers to the event of a disaster happening or striking. Often used in news reports and official announcements.
There are concerns about the occurrence of disasters due to the typhoon.
When a disaster occurs, first ensure your own safety.
災害 means 'disaster' itself, while 災害発生 refers specifically to the occurrence or outbreak of a disaster.
発生 is a general term for 'occurrence' or 'outbreak', used with many nouns (e.g., 事故発生, 問題発生). 災害発生 is a specific compound for disaster occurrence.
Compound of 災害 (disaster) and 発生 (occurrence). The kanji 災 means 'calamity', 害 means 'harm', 発 means 'departure/emit', and 生 means 'life/birth'. The reading はっせい is a standard rendaku-influenced reading of 発生.