Description may include, but is not limited to,

geophysical (e.g., earthquake, volcanic eruption, avalanche, subsidence)
hydro-meteorological (e.g., flood, drought, wildfire, weather, climate)
biological (e.g., epidemic, insect infestation, invasive species, animal stampede)

technological (e.g., engineering failure, transport disasters, environmental disasters)
sociological (e.g., criminal acts, riots, war)
effects of agricultural practices
point- and nonpoint-source pollution.

Process/Skill Questions:

How can a natural disaster be simultaneously a positive and a negative event?
What are examples of significant catastrophes caused by humans?
What are some adaptations of forests that help deal with natural disasters (e.g., forest fires)?
How could one formulate a plan to improve the water quality of a lake being contaminated by an identified source?
What invasive species have been introduced in Virginia? How have they affected ecosystems into which they were introduced?