Monitoring the Condition of Our Nation’s Streams and Rivers: From the Mountains to the Coasts.

The article focuses on the U.S. Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP). In the early 1990s, EMAP began testing statistically robust approaches for regional and national scale assessment of aquatic resources of the United States. EMAP's research on streams, lakes and coastal zones advanced the use of probability-based survey designs to yield statistically valid statements of the ecological conditions of these resources. The ability to infer conditions for the entire population of a resource sets the EMAP approach apart from site-specific approaches of other assessment programs.