National Synthesis teams synthesize the
results of all the NAWQA study-unit investigations
with information from other programs, agencies, and researchers.
These national syntheses are possible because each NAWQA study-unit
investigation adheres to a nationally consistent study design and
uniform methods of data collection and analysis. National syntheses
provide an understanding of how and why water quality varies regionally
and nationally.
National Synthesis results help to answer the following types
of questions:
- What water-quality issues occur only in isolated areas, and
what issues are pervasive across the nation?
- How do the effects on water quality of human activities, such
as pesticide applications, and natural factors, such as soil permeability,
differ across different environmental settings?
National Synthesis addresses priority water-quality issues:
Models are critical tools in National Synthesis:
SPARROW (Spatially
Referenced Regression on Watershed attributes), a national water-quality
model developed by the USGS
National Synthesis results include data and publications:
NAWQA
data warehouse
The Quality
of Our Nation's Waters-Nutrients and Pesticides, USGS Circular
1225 (1999)
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