Answer:
Lowering the land, is the right answer.
Step-by-step explanation:
The Dust Bowl was a period of time in which relentless dust storms that considerably ruined the agriculture and ecology of the prairies of the U.S. and Canada throughout the 1930's; relentless drought and a breakdown to practice dry-land farming techniques to check the aeolian methods (wind erosion) generated the event.
The Dust Bowl hit Iowa by blowing strong wind towards West/Central Iowa. It led to the emergence of food shortages and due to this many farmers to began to flee their homes and moving to the west.