Why did the Dust Bowl of the 1930s increase migration in the U.S.?

Responses

It was a sudden-onset event that led to voluntary migration.

It was a slow-onset change that led to forced migration.

It was a sudden-onset event that led to forced migration.

It was a slow-onset change that led to voluntary migration.

The Dust Bowl of the 1930s was a slow-onset change that led to forced migration.