Book Chapters
Science Quality and Integrity
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse more than 5,500 book chapters authored by our scientists over the past 100+ year history of the USGS and refine search by topic, location, year, and advanced search.
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Unsaturated zone flow processes
Water flow in the unsaturated zone is greatly influenced by unsaturated hydrostatics (water content, energy, pressure, and retention) and by unsaturated hydrodynamics (diffuse flow and preferential flow). Important multiphase processes include the transport of gases, nonaqueous liquids, and solid particles. Numerous means are available for determination of unsaturated conditions and properties, bo
Authors
John R. Nimmo
Modeling ground-water flow and quality
No abstract available.
Authors
Leonard F. Konikow, Pierre D. Glynn
Aquifer recharge
No abstract available.
Authors
John R. Nimmo, Richard W. Healy, David A. Stonestrom
Genus sulfurospirillum
No abstract available.
Authors
J.F. Stolz, Ronald S. Oremland, B.J. Paster, F.E. Dewhirst, P. Vandamme
Bufo canorus Camp 1916, Yosemite Toad.
Yosemite toads (Bufo canorus) are endemic to the Sierra Nevada, California, from Ebbetts Pass, Alpine County to the Spanish Mountain area, Fresno County (Karlstrom 1962, 1973;
Stebbins 1966; unpublished Sierra National
Forest survey data, 1995, 2002). Sites occur
from 1,950–3,444 m elevation, with the
majority of sites between 2,590–3,048 m
(Karlstrom, 1962). Jennings and Hayes
(1994a) estim
Authors
Carlos Davidson, Gary M. Fellers
Aneides hardii (Taylor, 1941): Sacramento Mountain salamander
No abstract available.
Authors
Cindy Ramotnik
Abundance and distribution of the common eider in eastern North America during the molting season
Like most other sea ducks, male common eiders (Somateria mollissima) concentrate in large groups to molt following the breeding season. Although Maine conducted surveys in the 1980s, little was known of eider molting sites in Atlantic Canada until recently, when surveys and research conducted in Quebec, Newfoundland, Labrador, Nova Scotia and Maine revealed a number of important molting sites. S
Authors
Jean-Pierre L. Savard, B. Allen, D. McAuley, G.R. Milton, S. Gililand
An objective method to determine an area's relative significance for avian conservation
Land managers are often concerned with providing habitat affords the 'best habitat for songbirds.' However, unless management simply is directed at rare species it may not be clear which habitats or management options are best. A standard, quantifiable measure to compare the significance of different tracts of land or competing management techniques for avian conservation would benefit managers
Authors
D.J. Twedt
Approaches for the direct estimation of rate of increase in population size using capture-recapture data
Recent developments in the modeling of capture-recapture data permit the direct estimation and modeling of population growth rate Pradel (1996). Resulting estimates reflect changes in numbers of birds on study areas, and such changes result from movement as well as survival and reproductive recruitment. One measure of the 'importance' of a demographic vital rate to population growth is based on
Authors
J. D. Nichols, T. Scott Sillett, J. E. Hines, Richard T. Holmes