Center for Earth and Environmental Science
Indiana University ~ Purdue University, Indianapolis

WATERSHEDS

Why Watershed?
Bob Barr

The watershed can then be viewed as a natural landscape unit, integrated by the streams flowing through the system. Changes within a streams watershed will therefore impact the physical, chemical and biological processes occurring within a stream corridor. Stream systems normally maintain a dynamic equilibrium with regards to water flow, sediment movement, temperature and other variables. This dynamic equilibrium can be lost if some of the streams variables go beyond normal ranges. When this dynamic equilibrium is lost many of the functions of the stream and riparian corridor can be lost until the stream is able to adjust to the new conditions. Frequently the riparian system will be degraded and lose functions as a result of the adjustment. The Lilly ARBOR Project that you will be working at is a site where we are studying how to reverse the degradation of riparian systems and how to best restore their critical functions.

• Synonyms -- drainage basin, catchment
• An area of land that drains into a central axial channel, or a lake or wetland
• The area of a drainage basin is proportional to both the length and the mean annual discharge of the river into which its waters drain
• Separated from other watersheds by drainage divides

An outline and note sheet has been provided in your packet

Background information on Watersheds

Topographic maps on the web

• Topozone (http://www.topozone.com/)
• USGS Geographic Names Information System

Center for Earth and Environmental Science
 School of Science
 Indiana University~Purdue University, Indianapolis
 723 West Michigan Street, SL118
 Indianapolis, IN 46202
 www.cees.iupui.edu
 cees@iupui.edu