The disaster information center of the prefectural government maintains a disaster prevention website, available in English at:
http://www-cds.osaka-bousai.net/en/pref/index.html.
Those who visit the site can register to receive email updates in English in case of emergency.
The international relations division of the prefectural government also provides the Osaka Information Service for Foreign Residents (OIS).
Inquiries are taken by phone or email, and may frequently asked questions are posted in English on the OIS website which can be accessed at:
http://www-cds.osaka-bousai.net/en/pref/index.html.