Conference Papers
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Browse almost 5,000 conference papers authored by our scientists and refine search by topic, location, year, and advanced search.
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Effect of climate change on watershed runoff
This paper examines forecasts of changes in watershed runoff in the Delaware River basin that result from a range of predicted effects of increased atmospheric carbon dioxide (CO2) on future precipitation, temperature, and stomatal resistance of plants. A deterministic hydrologic model, TOPMODEL, was driven with stochastic inputs of temperature and precipitation to derive the forecasts. Results in
Authors
D. M. Wolock, M. A. Ayers, L.E. Hay, G. J. McCabe
Effect of flow conditions on stream reaeration coefficients
Contrary to the findings of previous studies of channel-controlled stream reaches, it was found that, in four reaches of a small stream characterized by a series of pools and riffles, reaeration coefficients decrease with decreasing discharge. In the reach with the most pool-and-riffle development, the measured reaeration coefficient under low-flow conditions was 86 percent less than its value dur
Authors
James L. Smoot
Effects of runoff changes and sea level rise on salinity in the Delaware River estuary
The objective of this study is to investigate changes in the spatial distribution of salt in the Delaware Estuary resulting from climate induced changes in freshwater inflows and in the position of mean sea level. The approach adopted for this study is composed of two parts: An analysis of existing physical data in order to derive a basic understanding of the salt dynamics, and numerical simulatio
Authors
Roy A. Walters
Effects of vegetation on floods at four Arizona sites
Four examples show the effect of vegetation on stage, discharge or frequency of floods. An 8-year growth of trees on the streambed at site 1 increased channel roughness enough to cause the average water surface elevations that were computed for 10-year and 100-year floods to be 0.49 and 0.91 meters higher than those for a channel without vegetation. A 6-year growth of vegetation and sediment depos
Authors
B.N. Aldridge
Estimating urban flood-frequency characteristics
Methods in use by the U.S. Geological Survey to estimate flood-frequency characteristics for urban watersheds are compared with estimates based on the Soil Conservation Service TR-55 model. Data from four small urban watersheds in Georgia are used in the flood-peak and hydrograph comparisons.
Authors
M.E. Jennings, J.B. Atkins, E. J. Inman
Exploration computer applications to primary dispersion halos: Kougarok tin prospect, Seward Peninsula, Alaska, USA
Computer processing and high resolution graphics display of geochemical data were used to quickly, accurately, and efficiently obtain important decision-making information for tin (cassiterite) exploration, Seward Peninsula, Alaska (USA). Primary geochemical dispersion patterns were determined for tin-bearing intrusive granite phases of Late Cretaceous age with exploration bedrock lithogeochemistr
Authors
Jeffrey C. Reid
Extraction of terrain features from digital elevation models
Digital elevation models (DEMs) are being used to determine variable inputs for hydrologic models in the Delaware River basin. Recently developed software for analysis of DEMs has been applied to watershed and streamline delineation. The results compare favorably with similar delineations taken from topographic maps. Additionally, output from this software has been used to extract other hydrologic
Authors
Curtis V. Price, David M. Wolock, Mark A. Ayers
Flow modeling in the Toutle River, Washington
No abstract available.
Authors
Yasuyuki Shimizu, Randy L. Dinehart, J. Dungan Smith
Flow separation of currents in shallow water
Flow separation of currents in shallow coastal areas is investigated using a boundary layer model for two-dimensional (depth-averaged) tidal flow past an elliptic headland. If the shoaling region near the coast is narrow compared to the scale of the headland, bottom friction causes the flow to separate just downstream of the point where the pressure gradient switches from favoring to adverse. As l
Authors
Richard P. Signell
Geochemical controls of vanadium accumulation in fossil fuels
High vanadium contents in petroleum and other fossil fuels have been attributed to organic-matter type, organisms, volcanic emanations, diffusion of sea water, and epigenetic enrichment. However, these factors are inadequate to account for the high abundance of vanadium in some fossil fuels and the paucity in others. By examining vanadium deposits in sedimentary rocks with sparse organic matter, c
Authors
G. N. Breit, R. B. Wanty
Geochemical controls on vanadium accumulation in fossil fuels
High vanadium contents in petroleum and other fossil fuels have been attributed to organic-matter type, organisms, volcanic emanations, diffusion of sea water, and epigenetic enrichment. However, these factors are inadequate to account for the high abundance of vanadium in some fossil fuels and the paucity in others. By examining vanadium deposits in sedimentary rocks with sparse organic matter, c
Authors
G. N. Breit, R. B. Wanty
Geochemistry of thermal water from selected wells, Boise, Idaho
Samples of thermal water from selected wells in the Boise area were analyzed for chemical composition; stable isotopes of hydrogen, oxygen, and dissolved carbon; radioactive carbon; and dissolved-gas concentrations. Chemically, the waters are virtually identical to those of the adjacent Idaho batholith. Isotopically, the thermal waters are more depleted in deuterium and oxygen-18 than coldwater sp
Authors
Robert H. Mariner, H.W. Young, D. J. Parliman, William C. Evans