basin vs swale

basin

noun
  • A rock formation scooped out by water erosion. 

  • An area of land from which water drains into a common outlet; drainage basin. 

  • A wide bowl for washing, sometimes affixed to a wall. 

  • A depression, natural or artificial, containing water. 

verb
  • To serve as or become a basin. 

  • To shelter or enclose in a basin. 

  • To create a concavity or depression in. 

swale

noun
  • A shallow troughlike depression that's created to carry water during rainstorms or snow melts; a drainage ditch. 

  • A long narrow and shallow trough between ridges on a beach, running parallel to the coastline. 

  • Bioswale, a shallow trough dug into the land on contour (horizontally with no slope), whose purpose is to allow water time to percolate into the soil. 

  • A shallow, usually grassy depression sloping downward from a plains upland meadow or level vegetated ridgetop. 

  • A gutter in a candle. 

  • A low tract of moist or marshy land. 

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