droughts disease
Drought and derecho are two natural disasters that start with "D."
A drought is considered a natural disaster. Disease could also be considered a natural disaster.
An ice storm can be a natural disaster.
A natural disaster that starts with "H" is -Hurricane & -Heat Wave
landslide
Tornado
not that I know of. sorry. :(
monsoon flood, mudslide
Yasi
A disaster, like a calamity is a hugely problematic turn of events.
Yes: forest fire, flood.
That word would be disaster.