Key definitions
http://water.usgs.gov/wsc/glossary.html

Introduction to Hydrology
http://www.michigan.gov/deq/0,1607,7-135-3313_3684_3724-9352--,00.html
http://www.nws.noaa.gov/oh/hrl/dmip/intro.html

Mountain hydrology of the semi-arid western US
http://www.cuahsi.org/cyberseminars/Bales-20041111.pdf

Water Resources of the Western United States
http://wwwrcamnl.wr.usgs.gov/

Streamflow trends in the US
http://pubs.usgs.gov/fs/2005/3017/pdf/FS2005_3017.pdf

Stockton/Jacoby streamfow trends based on tree rings
http://wwa.colorado.edu/resources/colorado_river/stockton_jacoby.html