district vs orography

district

noun
  • An area or region marked by some distinguishing feature. 

  • the Soho district of London 

  • An administrative division of an area. 

  • An administrative division of a county without the status of a borough. 

verb
  • To divide into administrative or other districts. 

orography

noun
  • the orographic features of a region 

  • the scientific study, or a physical description of mountains 

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