Conference Papers
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The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse almost 5,000 conference papers authored by our scientists and refine search by topic, location, year, and advanced search.
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Use of spatial statistics and isotopic tracers to measure the influence of arsenical pesticide use on stream sediment chemistry in New England, USA
Arsenical pesticides and herbicides, principally Pb arsenate, Ca arsenate, and Na arsenate with lesser use of other metal-As pesticides, were widely applied on apple, blueberry, and potato crops in New England during the first half of the twentieth century. Agricultural census data for this time period is used to define an agricultural index that identifies areas that are inferred to have used ars
Authors
G. R. Robinson, R. A. Ayuso
Use of stream chemistry for monitoring acidic deposition effects in the Adirondack region of New York
Acid-neutralizing capacity (ANC) and pH were measured weekly from October 1991 through September 2001 in three streams in the western Adirondack Mountain region of New York to identify trends in stream chemistry that might be related to changes in acidic deposition. A decreasing trend in atmospheric deposition of SO42- was observed within the region over the 10-yr period, although most of the decr
Authors
G. B. Lawrence, B. Momen, K. M. Roy
Using borehole flow data to characterize the hydraulics of flow paths in operating wellfields
Understanding the flow paths in the vicinity of water well intakes is critical in the design of effective wellhead protection strategies for heterogeneous carbonate aquifers. High-resolution flow logs can be combined with geophysical logs and borehole-wall-image logs (acoustic televiewer) to identify the porous beds, solution openings, and fractures serving as conduits connecting the well bore to
Authors
F. Paillet, J. Lundy
Using discrete choice modeling to generate resource selection functions for female polar bears in the Beaufort Sea
Polar bears (Ursus maritimus) depend on ice-covered seas to satisfy life history requirements. Modern threats to polar bears include oil spills in the marine environment and changes in ice composition resulting from climate change. Managers need practical models that explain the distribution of bears in order to assess the impacts of these threats. We explored the use of discrete choice models to
Authors
George M. Durner, Steven C. Amstrup, Ryan M. Nielson, Trent McDonald
Variability of hydrologic regimes and morphology in constructed open-ditch channels
Open-ditch ecosystems are potential transporters of considerable loads of nutrients, sediment, pathogens and pesticides from direct inflow from agricultural land to small streams and larger rivers. Our objective was to compare hydrology and channel morphology between two experimental open-ditch channels. An open-ditch research facility incorporating a paired design was constructed during 2002 near
Authors
J.S. Strock, J.A. Magner, W. B. Richardson, M.J. Sadowsky, G.R. Sands, R.T. Venterea
Variation in freshwater growth and development among five New England Atlantic salmon (Salmo salar) populations reared in a common environment
We examined phenotypic variation in growth and development from the eyed-egg stage to the age-1+ smolt stage among five New England populations of Atlantic salmon (Salmo salar: East Machias, Narraguagus, Sheepscot, Penobscot, Connecticut) reared in a common laboratory environment. Study populations originated from rivers varying in size, latitude, and level of hatchery supplementation and included
Authors
M. Obedzinski, B. H. Letcher
Visual enhancement of unmixed multispectral imagery using adaptive smoothing
Adaptive smoothing (AS) has been previously proposed as a method to smooth uniform regions of an image, retain contrast edges, and enhance edge boundaries. The method is an implementation of the anisotropic diffusion process which results in a gray scale image. This paper discusses modifications to the AS method for application to multi-band data which results in a color segmented image. The proce
Authors
G.P. Lemeshewsky
Water loss in the Potomac River basin during droughts
The water loss phenomena in the Washington DC metropoliton area's (WMA) Potomac River water supply basin during droughts was analyzed. Gage errors, permitted withdrawals, evaporation, and transpiration by trees along the river were investigated to account for loss. The Interstate Commission on the Potomac River Basin (ICPRB) calculated potential gage error and examined permits to determine permitt
Authors
E.R. Hagen, J.E. Kiang, J.J.A. Dillow
Why aren't there more beaver in Rocky Mountain National Park?
No abstract available.
Authors
B. W. Baker, D. Mitchell, H.C. Ducharme, T.R. Stanley, H.R. Peinetti
Winter growth and survival of juvenile Atlantic salmon (Salmo salar) in experimental raceways
We used experimental raceways to determine overwinter mortality of wild-reared immature and mature post-young-of-the-year Atlantic salmon (Salmo salar). Secondarily, we investigated the effects of differing treatments (velocity and shelter) on winter growth and survival. Overall survival from November to April was 94%, and survival of immature (98%) and mature (90%) parr, although statistically di
Authors
D.L. Parrish, E.J. Hawes, K.G. Whalen
WTAQ - A computer program for aquifer-test analysis of confined and unconfined aquifers
Computer program WTAQ was developed to implement a Laplace-transform analytical solution for axial-symmetric flow to a partially penetrating, finite-diameter well in a homogeneous and anisotropic unconfined (water-table) aquifer. The solution accounts for wellbore storage and skin effects at the pumped well, delayed response at an observation well, and delayed or instantaneous drainage from the un
Authors
P. M. Barlow, A.F. Moench
Thermochronology of secondary minerals from the Yucca Mountain unsaturated zone
No abstract available.
Authors
Joseph F. Whelan, Leonid A. Neymark, Edwin Roedder, Richard J. Moscati