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April 18, 2016

This week’s EarthWord sounds like what the British might call an outhouse...


A map of the Chesapeake Bay Watershed, showing various land-covers and land-uses. Credit: USGS

EarthWords is an on-going series in which we shed some light on the complicated, often difficult-to-pronounce language of science. Think of us as your terminology tour-guides, and meet us back here every week for a new word!

The EarthWord: Watershed


  • Although it looks like an alternate name for an outhouse, a watershed is the area of land where all of the water that falls in it and drains off of it goes into the same place. For instance, the Chesapeake Bay Watershed is made of all of the land and rivers that send water into the Chesapeake Bay.

Use/Significance in the Earth Science Community:

  • Watersheds are key landscape-level ecosystems, because they predict water availability (both for human and ecosystem use), demonstrate erosion pathways, and can even illustrate the spread of chemicals and nutrients throughout a region.


  • USGS researches watersheds extensively. Using Landsat and other remote-sensing tools, USGS scientists track landscape-level changes to watersheds, such as the conversion of grasslands to croplands. In addition, USGS scientists in Water Science Centers follow streams and creeks into larger rivers to track the spread of nutrients like nitrogen from fertilizers or chemicals like pharmaceuticals.

Next EarthWord: Think our bad jokes for EarthWords are drying up? Think again...

Hungry for some science, but you don’t have time for a full-course research plate? Then check out USGS Science Snippets, our snack-sized science series that focuses on the fun, weird, and fascinating stories of USGS science.