Answer (example: flood):
Reasons: very heavy and continuous rainfall, cloudburst, sudden release of water from dams, blocked drains and encroachment on river banks, and deforestation.
Effects: loss of human and animal life; damage to houses, roads, railways and crops; disruption of transport and power supply; spread of waterborne diseases.
Remedial measures: early warning and evacuation of people to safe places; relief camps with food, clean water and medicines; rescue teams (NDRF); keeping drains clear, building embankments, afforestation and planned release of water from dams.