How can people be guided after a severe flood to understand that this is a trial from Allah and a future blessing, taking into consideration that environmental degradation (and not moral corruption) might play a role in these phenomena?

Everything that occurs in the universe happens by Allah's divine decree (Qada') and preordainment (Qadar) for a wisdom. Among these wisdoms are: testing His servants with patience or gratitude, serving as a lesson and reminder of Allah's power, acting as a warning and caution against sins, or as a punishment for them. What befalls a righteous believer purifies their sins and elevates their ranks. Floods and other such phenomena are not purely evil; rather, they contain much good. The environment's susceptibility to these phenomena does not deviate from what has been mentioned. Legal transgressions (violations of Islamic law) affect the environment. The greatest danger is if people do not learn lessons and repent to Allah.