inundation vs landflood

inundation

noun
  • The act of inundating; an overflow; a flood; a rising and spreading of water over grounds. 

  • The state of being inundated; flooding 

  • An overflowing or superfluous abundance; a flood; a great influx 

landflood

noun
  • An overflowing of land by river; an inundation or freshet. 

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