v, 18 pages : illustrations (some color), color maps ; 28 cm
OCLC
ocm56513066
Includes bibliographical references (page 18).
Also available on the Internet at the USGS web site. Address as of 10/26/04: http://water.usgs.gov/pubs/sir/2004/5094/pdf/sir2004-5094.pdf; current access available via PURL.