flooding vs natural disaster

flooding

noun
  • An act of flooding; a flood or gush. 

  • A form of therapy that treats a phobia by suddenly exposing the patient to the object of the phobia, instead of approaching it gradually. 

  • Emotional overwhelm sometimes leading to a primal state of rage or panic. 

natural disaster

noun
  • The emergency situation that is the consequence of such an event. 

  • Any natural phenomenon that causes great damage and loss of life. 

How often have the words flooding and natural disaster occurred in a corpus of books? (source: Google Ngram Viewer )