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United States Geological Survey: Staff Publications

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Full-Text Articles in Earth Sciences

Evidence Of Active Dune Sand On The Great Plains In The 19th Century From Accounts Of Early Explorers, Daniel R. Muhs, Vance T. Holliday Jan 1995

Evidence Of Active Dune Sand On The Great Plains In The 19th Century From Accounts Of Early Explorers, Daniel R. Muhs, Vance T. Holliday

United States Geological Survey: Staff Publications

Eolian sand is extensive over the Great Plains of North America, but is at present mostly stabilized by vegetation. Accounts published by early explorers, however, indicate that at least parts of dune fields in Nebraska, Colorado, Kansas, New Mexico, and Texas were active in the 19th century. Based on an index of dune mobility and a regional tree-ring record, the probable causes for these periods of greater eolian activity are droughts, accompanied by higher temperatures, which greatly lowered the precipitationto- evapotranspiration ratio and diminished the cover of stabilizing vegetation. In addition, observations by several explorers, and previous historical studies, indicate …

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Recent State Of Stress Change In The Walker Lane Zone, Western Basin And Range Province, United States, Oliver Bellier, Mary Lou Zoback Jan 1995

Recent State Of Stress Change In The Walker Lane Zone, Western Basin And Range Province, United States, Oliver Bellier, Mary Lou Zoback

United States Geological Survey: Staff Publications

The NW to north-trending Walker Lane zone (WLZ) is located along the western boundary of the northern Basin and Range province with the Sierra Nevada. This zone is distinguished from the surrounding Basin and Range province on the basis of irregular topography and evidence for both normal and strike-slip Holocene faulting. Inversion of slip vectors from active faults, historic fault offsets, and earthquake focal mechanisms indicate two distinct Quaternary stress regimes within the WLZ, both of which are characterized by a consistent WNW σ3 axis; these are a normal faulting regime with a mean σ3 axis of N85 °+ …

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Birds Of The Platte, Eileen M. Kirsch Jan 1995

Birds Of The Platte, Eileen M. Kirsch

United States Geological Survey: Staff Publications

Gary Lingle has done an outstanding job compiling information to make birding the Central Platte River and Rainwater Basin area of Nebraska easier and more rewarding. The book was not designed to replace a field guide. Rather, it provides maps, general information about the area, when and where birds can be seen, and likelihood of viewing each of 300 bird species possible. Sprinkled throughout the book are drawings by William S. Whitney and Ernest V. Ochsner that depict the structural simplicity of the prairie and the diversity of its wildlife. The writing style is personal and unpretentious, and the text …

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Foreshock Sequence Of The 1992 Landers, California, Earthquake And Its Implications For Earthquake Nucleation, Douglas A. Dodge, Gregory C. Beroza, W. L. Ellsworth Jan 1995

Foreshock Sequence Of The 1992 Landers, California, Earthquake And Its Implications For Earthquake Nucleation, Douglas A. Dodge, Gregory C. Beroza, W. L. Ellsworth

United States Geological Survey: Staff Publications

The June 28, 1992, Landers, California, earthquake(Mw=7.3) was preceded for about 7 hours by a foreshock sequence consisting of at least 28 events. In this study we examine the geometry and temporal development of the foreshocks using high-precision locations based on cross correlation of waveforms recorded at nearby stations. By aligning waveforms, rather than trying to obtain travel time picks for each event independently, we are able to improve the timing accuracy greatly and to make very accurate travel time picks even for emergent arrivals. We perform a joint relocation using the improved travel times and reduce the …

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Geomorphic And Geochemical Evidence For The Source Of Sand In The Algodones Dunes, Colorado Desert, Southeastern California, Daniel R. Muhs, Charles A. Bush, Scott D. Cowherd, Shannon Mahan Jan 1995

Geomorphic And Geochemical Evidence For The Source Of Sand In The Algodones Dunes, Colorado Desert, Southeastern California, Daniel R. Muhs, Charles A. Bush, Scott D. Cowherd, Shannon Mahan

United States Geological Survey: Staff Publications

The Algodones dunes of southeastern California comprise one of the largest active dune fields in the United States. The source of sand of the Algodones dunes is controversial, and the source of stabilized aeolian sand in the adjacent East Mesa area has not been investigated at all. We used mineralogical compositions and trace element concentrations to ascertain the most likely source of sand for these active and stabilized dunes. Results indicate that alluvium derived from the San Bernardino Mountains, which enters the Salton trough to the northwest of the dune fields, and alluvium derived from the Chocolate Mountains, which is …

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Carbonate Deposition, Pyramid Lake Subbasin, Nevada: 2. Lake Levels And Polar Jet Stream Positions Reconstructed From Radiocarbon Ages And Elevations Of Carbonates (Tufas) Deposited In The Lahontan Basin, Larry Benson, Michaele Kashgarian, Meyer Rubin Jan 1995

Carbonate Deposition, Pyramid Lake Subbasin, Nevada: 2. Lake Levels And Polar Jet Stream Positions Reconstructed From Radiocarbon Ages And Elevations Of Carbonates (Tufas) Deposited In The Lahontan Basin, Larry Benson, Michaele Kashgarian, Meyer Rubin

United States Geological Survey: Staff Publications

Most of the tufas in the Pyramid Lake subbasin were deposited within the last 35,000 yr, including most of the mound tufas that border the existing lake. Many of the older tufas (> 21,000 yr B.P.) contained in the mounds were formed in association with ground-water discharge. The radiocarbon (14C) ages of the older tufas represent maximum estimates of the time of their formation. Lake Lahontan experienced large and abrupt rises in level at ~ 22,000, 15,000, and 11,000 yr B.P. and three abrupt recessions in level at ~ 16,000, 13,600, and 10,000 yr B.P. The lake-level rises …

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Fault Healing Inferred From Time Dependent Variations In Source Properties Of Repeating Earthquakes, Chris Marone, John E. Vidale, William L. Ellsworth Jan 1995

Fault Healing Inferred From Time Dependent Variations In Source Properties Of Repeating Earthquakes, Chris Marone, John E. Vidale, William L. Ellsworth

United States Geological Survey: Staff Publications

We analyze two sets of repeating earthquakes on the Calaveras fault to estimate in-situ rates of fault strengthening (healing). Earthquake recurrence intervals t, range from 3 to 803 days. Variations in relative moment and duration are combined to study changes in stress drop, rupture dimension, rupture velocity, and particle velocity as a function of tr. Healing rates and source variations are compared with predictions of laboratory derived friction laws. Two interpretations of event duration τ are used: one in which τ: is given by the ratio of slip to particle velocity and one in which it scales as …

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Kinetics Of Pressure Solution At Halite-Silica Interfaces And Intergranular Clay Films, Stephen H. Hickman, Brian Evans Jan 1995

Kinetics Of Pressure Solution At Halite-Silica Interfaces And Intergranular Clay Films, Stephen H. Hickman, Brian Evans

United States Geological Survey: Staff Publications

Pressure solution is widely regarded as a potentially important deformation
mechanism along crustal faults and during a diagenesis, yet the mechanisms and kinetics of this process remain highly controversial. To better understand the fundamental factors controlling the rates of pressure solution at the grain-to-grain scale, we conducted experiments in which convex halite lenses were pressed against fiats of fused silica in brine. Fluid pressures were maintained at 0.1 MPa; temperatures and mean contact normal stresses ranged from 8.3 ° to 90.2 °C and 0.5 to 13.5 MPa, respectively. The geometry and growth rate of the contact spot between the two …

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Geochemical Evidence Of Saharan Dust Parent Material For Soils Developed On Quaternary Limestones Of Caribbean And Western Atlantic Islands, Daniel R. Muhs, Charles A. Bush, Kathleen C. Stewart, Tracy R. Rowland, Russell C. Crittenden Jan 1994

Geochemical Evidence Of Saharan Dust Parent Material For Soils Developed On Quaternary Limestones Of Caribbean And Western Atlantic Islands, Daniel R. Muhs, Charles A. Bush, Kathleen C. Stewart, Tracy R. Rowland, Russell C. Crittenden

United States Geological Survey: Staff Publications

Most previous workers have regarded the insoluble residues of high-purity Quatemary limestones (coral reefs and oolites) as the most important parent material for well-developed, clay-rich soils on Caribbean and western Atlantic islands, but this genetic mechanism requires unreasonable amounts of limestone solution in Quatemary time. Other possible parent materials from external sources are volcanic ash from the Lesser Antilles island arc and Saharan dust carried across the Atlantic Ocean on the northeast trade winds. Soils on Quatemary coral terraces and carbonate eolianites on Barbados, Jamaica, the Florida Keys (United States), and New Providence Island (Bahamas) were studied to determine which, …

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A Metapopulation Approach To Pitcher's Thistle (Cirsium Pitcheri) Recovery In Southern Lake Michigan Dunes, A. Kathryn Mceachern, Marlin L. Bowles, Noel B. Pavlovic Jan 1994

A Metapopulation Approach To Pitcher's Thistle (Cirsium Pitcheri) Recovery In Southern Lake Michigan Dunes, A. Kathryn Mceachern, Marlin L. Bowles, Noel B. Pavlovic

United States Geological Survey: Staff Publications

Successful recovery planning for a rare species relies upon knowledge of its life history and ecology, as well as an understanding of its habitat requirements and disturbance regime (Gilpin & Soule 1986, Lande 1988a). Species that depend upon early-successional or transient habitats in landscape mosaics present unique recovery challenges (Menges 1990). They require perpetuation of multiple populations within a shifting mosaic of local habitats. Recovery plans for these species must be formulated from an understanding of population demography within the context of community and landscape dynamics. Processes that maintain landscape mosaics must be given long-term protection if recovery is to …

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Thorium-230 Ages Of Corals And Duration Of The Last Interglacial Sea-Level High Stand On Oahu, Hawaii, Barney J. Szabo, Kenneth R. Ludwig, Daniel R. Muhs, Kathleen R. Simmons Jan 1994

Thorium-230 Ages Of Corals And Duration Of The Last Interglacial Sea-Level High Stand On Oahu, Hawaii, Barney J. Szabo, Kenneth R. Ludwig, Daniel R. Muhs, Kathleen R. Simmons

United States Geological Survey: Staff Publications

Thorium-230 ages of emergent marine deposits on Oahu, Hawaii, have a uniform dis- tribution of ages from ~114,000 to ~131,000 years, indicating a duration for the last interglacial sea-level high stand of ~17,000 years, in contrast to a duration of ~8000 years inferred from the orbitally tuned marine oxygen isotope record. Sea level on Oahu rose to ≥1 to 2 meters higher than present by 131,000 years ago or ~6000 years earlier than inferred from the marine record. Although the latter record suggests a shift back to glacial conditions beginning at ~119,000 years ago, the Oahu coral ages indicate a …

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Stable Isotopes Of Oxygen And Hydrogen In The Truckee River-Pyramid Lake Surface-Water System, 3: Source Of Water Vapor Overlying Pyramid Lake, Larry Benson, J. W. C. White Jan 1994

Stable Isotopes Of Oxygen And Hydrogen In The Truckee River-Pyramid Lake Surface-Water System, 3: Source Of Water Vapor Overlying Pyramid Lake, Larry Benson, J. W. C. White

United States Geological Survey: Staff Publications

During 1988 and 1989, a series of water-vapor extractions were conducted in the Pyramid Lake basin to determine the source of moisture that overlies the lake. Calculations of the isotopic and water-vapor balances were made from isotopic and meteorological data from the Pyramid Lake and Reno, Nevada, areas. The results indicate that in the warm season, most of the moisture that overlies the lake is derived from evaporation as opposed to advected moisture. Isotopic fluxes at the lake surface can be approximated by climatic data from the lake site, which simplifies the calculation of this input in numerical simulations of …

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Stable Isotopes Of Oxygen And Hydrogen In The Truckee River-Pyramid Lake Surface-Water System, 2. A Predictive Model Of Δ18O And Δ2H In Pyramid Lake, S. W. Hostetler, Larry Benson Jan 1994

Stable Isotopes Of Oxygen And Hydrogen In The Truckee River-Pyramid Lake Surface-Water System, 2. A Predictive Model Of Δ18O And Δ2H In Pyramid Lake, S. W. Hostetler, Larry Benson

United States Geological Survey: Staff Publications

A physically based model of variations in δ18O and δ2H in Pyramid Lake is presented. For inputs, the model uses measurements of liquid water inflows and outflows and their associated isotopic compositions and a set of meteorological data (radiative fluxes, air temperature, relative humidity, and windspced). The model simulates change of lake volume, thermal and isotopic stratification, evaporation, and the isotopic composition of evaporation. A validation of the model for 1987-1989 and 1991 indicates that it can reproduce measured intra- and interannual variations of δ18O and δ2H. Three applications of the model …

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Stable Isotopes Of Oxygen And Hydrogen In The Truckee River-Pyramid Lake Surface-Water System. 1. Data Analysis And Extraction Of Paleoclimatic Information, Larry Benson Jan 1994

Stable Isotopes Of Oxygen And Hydrogen In The Truckee River-Pyramid Lake Surface-Water System. 1. Data Analysis And Extraction Of Paleoclimatic Information, Larry Benson

United States Geological Survey: Staff Publications

The δ18O content of streamflow discharge entering Pyramid Lake is a simple mixture of isotopically enriched Lake Tahoe discharge and isotopically depleted snowmelt. The δ18O value of Pyramid Lake water varies continuously, as isotopically depleted water evaporates from the epilimnion and isotopically depicted water enters the lake as streamflow discharge and on-lake precipitation. In a normal water year, the δ18O of Pyramid Lake surface water varies seasonally because the components of the hydrologic balance in the Pyramid Lake system are seasonally shifted. The problem of isotopic and thermal heterogeneity can be minimized by analyzing …

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Initial Reference Models In Local Earthquake Tomography, E. Kissling, W. L. Ellsworth, D. Eberhart-Phillips, U. Kradolfer Jan 1994

Initial Reference Models In Local Earthquake Tomography, E. Kissling, W. L. Ellsworth, D. Eberhart-Phillips, U. Kradolfer

United States Geological Survey: Staff Publications

The inverse problem of three-dimensional (3-D) local earthquake tomography is formulated as a linear approximation to a nonlinear function. Thus the solutions obtained and the reliability estimates depend on the initial reference model. Inappropriate models may result in artifacts of significant amplitude. Here, we advocate the application of the same inversion formalism to determine hypocenters and one-dimensiona(1-D) velocity model parameters, including station corrections, as the first step in the 3-D modeling process. We call the resulting velocity model the minimum 1-D model.  For test purposes,  synthetic data set based on the velocity structure of the San Andreas fault zone in …

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Effects Of Lithology And Depth On The Permeability Of Core Samples From The Kola And Ktb Drill Holes, C. Morrow, D. Lockner, S. Hickman, M. Rusanov, T. Röckel Jan 1994

Effects Of Lithology And Depth On The Permeability Of Core Samples From The Kola And Ktb Drill Holes, C. Morrow, D. Lockner, S. Hickman, M. Rusanov, T. Röckel

United States Geological Survey: Staff Publications

Permeability measurements were conducted on intact core samples from
the Kola drill hole in Russia and the KTB drill hole in Germany. Samples included granodiorite gneisses, basalts and amphibolites from depths up to 11 km. The tests were intended to determine the pressure sensitivity of permeability and to compare the effects of stress relief and thermal microcracking on the matrix permeability of different rock types and similar samples from different depths. The pore pressure Pp was fixed at the estimated in situ pressure assuming a normal hydrostatic gradient;
the confining pressure Pc was varied to produce effective pressures(P …

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Ultrasonic Velocities In Cores From The Kola Superdeep Well And The Nature Of Subhorizontal Seismic Reflections, Lev Vernik, Stephen Hickman, David Lockner, Michael Rusanov Jan 1994

Ultrasonic Velocities In Cores From The Kola Superdeep Well And The Nature Of Subhorizontal Seismic Reflections, Lev Vernik, Stephen Hickman, David Lockner, Michael Rusanov

United States Geological Survey: Staff Publications

P wave velocity and orthogonally polarized S wave velocities were
measured on 12 cores recovered from the Kola superdeep well at depths of 0 to 12 km. Measurements were made along the core axis at a frequency of 1 MHz, at confiningp ressures ranging from 2 to 100 MPa, and under dry and water-saturated conditions. Cores were chosen to sample a variety of lithologies and were used to estimate interval velocities based on a simplified geological column of the well. These interval velocities were then compared with sonic log and vertical seismic profile (VSP) data. High-pressure lab velocities  correlated primarily …

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Herbicide Interchange Between A Stream And The Adjacent Alluvial Aquifer, Wuncheng Wang, Paul Squillace Jan 1994

Herbicide Interchange Between A Stream And The Adjacent Alluvial Aquifer, Wuncheng Wang, Paul Squillace

United States Geological Survey: Staff Publications

Herbicide interchange between a stream and the adjacent alluvial aquifer and quantification of herbicide bank storage during high streamflow were investigated at a research site on the Cedar River flood plain, 10 km southeast of Cedar Rapids, Iowa. During high streamflow in March 1990, alachlor, atrazine, and metolachlor were detected at concentrations above background in water from wells as distant as 20, 50, and 10 m from the river’s edge, respectively. During high streamflow in May 1990, alachlor, atrazine, cyanazine, and metolachlor were detected at concentrations above background as distant as 20, 50, 10, and 20 m from the river’s …

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Exceptionally Well-Preserved Early Oligocene Diatoms From Glacial Sediments Of Prydz Bay, East Antarctica, John A. Barron, Albert D. Mahood Jan 1993

Exceptionally Well-Preserved Early Oligocene Diatoms From Glacial Sediments Of Prydz Bay, East Antarctica, John A. Barron, Albert D. Mahood

United States Geological Survey: Staff Publications

An exceptionally well-preserved early Oligocene diatom assemblage is documented and illustrated from the internal sediment of a gastropod shell, which was collected from glacial sediments recovered at Ocean Drilling Program Site 739 on the continental shelf in Prydx Bay, Antarctica. The diatoms were deposited between 35.9 and 34.8 Ma according to diatom and calcareous nannofossil stratigraphy, apparently soon after a period of major ice sheet advance across the Prydz Bay continental shelf. The diatom assemblage is neritic in character. but it can readily be correlated with open ocean assemblages from the Southern Ocean as well as with similar material recovered …

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Short-Term Sediment Accumulation Rates Determined From Eocene Alluvial Paleosols, Mary J. Kraus, Thomas M. Bown Jan 1993

Short-Term Sediment Accumulation Rates Determined From Eocene Alluvial Paleosols, Mary J. Kraus, Thomas M. Bown

United States Geological Survey: Staff Publications

A new method uses alluvial paleosols to calculate sediment accumulation rates for thin (25 m) stratigraphic intervals and allows the reliable interpolation of ages for stratigraphic levels within a thick stratigraphic interval bounded by established dates. Sediment accumulation rates calculated for a 650 m composite section in the Eocene Willwood Formation of Wyoming span time intervals ranging from only 0.05 to 0.25 may. Important sedimentologic changes coincide with changes in accumulation rate and indicate close and direct relations between the history of basin subsidence and depositional patterns.

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Systematics, Biostratigraphy, And Dental Evolution Of The Palaeothentidae, Later Oligocene To Early-Middle Miocene (Deseadan-Santacrucian) Caenolestoid Marsupials Of South America, Thomas M. Bown, John G. Fleagle Jan 1993

Systematics, Biostratigraphy, And Dental Evolution Of The Palaeothentidae, Later Oligocene To Early-Middle Miocene (Deseadan-Santacrucian) Caenolestoid Marsupials Of South America, Thomas M. Bown, John G. Fleagle

United States Geological Survey: Staff Publications

The family Palaeothentidae contains some of the dentally more specialized of the small-bodied marsupials of South America and was a clade almost equivalent with the Abderitidae in having been the most abundant caenolestoids. They were unquestionably the most diverse, containing two subfamilies, nine genera, and 19 species, with a distribution ranging from Colombia to Tierra del Fuego. The best and most continuous record of the Palaeothentidae is from Patagonian Argentina where eight genera and 17 species are recognized. There, the Palaeothentidae ranged in age from the Deseadan (later Oligocene) through the late Santacrucian (middle Miocene-the Santacrucian record lasting from about …

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Seismotectonics Of The San Andreas Fault System Between Point Arena And Cape Mendocino In Northern California' Implications For The Development And Evolution Of A Young Transform, David A. Castillo, William L. Ellsworth Jan 1993

Seismotectonics Of The San Andreas Fault System Between Point Arena And Cape Mendocino In Northern California' Implications For The Development And Evolution Of A Young Transform, David A. Castillo, William L. Ellsworth

United States Geological Survey: Staff Publications

The northernmost and relatively youthful segment of the San Andreas fault system is situated within a 100+ km wide zone of northwest trending strike-slip faults that includes, from west to east, the San Andreas, Maacama, and Bartlett Springs faults. Although the San Andreas fault is the principal strike-slip fault in this system, it has been virtually aseismic since the 1906 earthquake. Moderate levels of seismicity locate to the east along the Maacama fault and, to a lesser extent, the Bartlett Springs fault at focal depths typical of other strike-slip faults within the San Andreas fault system in central California. North …

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Time-Stratigraphic Reconstruction And Integration Of Paleopedologic, Sedimentologic, And Biotic Events (Willwood Formation, Lower Eocene, Northwest Wyoming, U.S.A.), Thomas M. Bown, Mary J. Kraus Jan 1993

Time-Stratigraphic Reconstruction And Integration Of Paleopedologic, Sedimentologic, And Biotic Events (Willwood Formation, Lower Eocene, Northwest Wyoming, U.S.A.), Thomas M. Bown, Mary J. Kraus

United States Geological Survey: Staff Publications

Relative paleosol maturities are inversely proportional to the accumulation rates of the sediment upon which they formed, and are therefore excellent relative indicators of how much geologic time elapsed between any two horizons. An empirically-based model is advanced using paleosol maturities to estimate the relative geologic time separating any stratigraphic levels within the lower Eocene Willwood Formation. The revised Willwood time stratigraphy from this analysis helps evaluate the nature, tempo, and possible causes of three major episodes of mammalian appearance and disappearance. These faunal events are directly correlated with certain aspects of paleosol evolution in the Willwood Formation. That evolution …

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Vedernikov's Number As A Measure Of Flow Stability, Cheng-Lung Chen Jan 1992

Vedernikov's Number As A Measure Of Flow Stability, Cheng-Lung Chen

United States Geological Survey: Staff Publications

In 1946, Vedernikov developed a stability criterion for uniform flow in open channels. A global parameter proposed by Vedernikov has been widely accepted as a measure of flow stability. Recognizing the significance of the role of the parameter playing in the stability of open-channel flows, hydraulicians have thenceforth called it the Vedernikov number. Alternatively, the Vedernikov number may be considered as an extended form of the Froude number because it equals the Froude number mUltiplied by an exponent of the hydraulic radius in the uniform-flow formula and a shape factor of channel section. A stability criterion can thus be formulated …

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Aminostratigraphy And Oxygen Isotope Stratigraphy Of Marine Terrace Deposits Palos Verdes Hills And San Pedro Areas Los Angeles County California, Daniel R. Muhs, Gifford H. Miller, Joseph F. Whelean, George L. Kennedy Jan 1992

Aminostratigraphy And Oxygen Isotope Stratigraphy Of Marine Terrace Deposits Palos Verdes Hills And San Pedro Areas Los Angeles County California, Daniel R. Muhs, Gifford H. Miller, Joseph F. Whelean, George L. Kennedy

United States Geological Survey: Staff Publications

Amino acid and oxygen isotope data for fossils from terraces of the Palos Verdes Hills and San Pedro areas in Los Angeles County California shed new light on the ages of terraces sea level history marine paleotemperatures and late Quaternary tectonics in this region Low terraces on the Palos Verdes peninsula correlate with the 80 ka and 125 ka sea level highstands that are also recorded as terraces on other coasts In San Pedro the Palos Verdes sand the deposit on what is mapped as the first terrace by Woodring and others 1946 was previously thought to be a single …

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Wspro Files For Slope-Area Computations, Janice M. Fulford Jan 1992

Wspro Files For Slope-Area Computations, Janice M. Fulford

United States Geological Survey: Staff Publications

A new program based on the U. S. Geological Survey slope-area program for indirectly computing peak discharges allows users to employ input data formats used by the water surface profile program WSPRO. The program source is written in Fortran 77 and can be ported easily to any computer that has standard Fortran 77 compilers. The program has been run on mini-computers and personal computers and does not use or require graphics capability, a color monitor, or a mouse.

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Mesh-Generating Computer Program For The Feswms-2dh Surface-Water Flow Model, Kirk G. Thibodeaux Jan 1992

Mesh-Generating Computer Program For The Feswms-2dh Surface-Water Flow Model, Kirk G. Thibodeaux

United States Geological Survey: Staff Publications

A mesh-generating computer program, GNMESH, has been developed to generate two-dimensional finite element meshes for the U.S. Federal Highway Administration's FESWMS-2DH, a two-dimensional depth averaged finite element flow model. GNMESH uses a modified mapping technique that incorporates piecewise Hermitian and weighted interpolation schemes to layout the generated mesh within given or calculated flow tubes. Minimum required input data for GNMESH is required when the program is run using its default settings. These input data consists of the X, Y, and Z coordinates of points defining a minimum of three cross sections, the roughness coefficients at the given cross sections, an …

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Rainfall-Runoff Relations For The Puget Sound Area, R. S. Dinicola Jan 1992

Rainfall-Runoff Relations For The Puget Sound Area, R. S. Dinicola

United States Geological Survey: Staff Publications

The characteristics of rainfall-runoff relations were hypothesized for the study area using existing information. These hypotheses were incorporated into the Hydrologic Simulation Program-FORTRAN, and the model was calibrated concurrently at 21 stream-gage sites in the study area. The simulation errors after model calibration were not large enough to reject the hypothesized characteristics. A proxy-basin validation effort was performed.

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Characteristics Of U.S. Geological Survey Discharge Measurements For Water Year 1990, Janice M. Fulford Jan 1992

Characteristics Of U.S. Geological Survey Discharge Measurements For Water Year 1990, Janice M. Fulford

United States Geological Survey: Staff Publications

The U.S. Geological Survey (USGS) Water Resources Division makes ten of thousands of stream discharge measurements each year throughout the United States and Puerto Rico. The majority of the measurements requires the use of point velocity instrumentation. Interest in new instrumentation technology and the performance of in-use instrumentation prompted a survey of current-meter usage and discharge measurement data for water year 1990. This paper is a summary of survey results: the velocity, discharge and depth ranges measured; the types of meters used; and the measurement problems encountered.

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Watershed Models For Resources Management Decisions, Alan M. Lumb Jan 1992

Watershed Models For Resources Management Decisions, Alan M. Lumb

United States Geological Survey: Staff Publications

Comprehensive hydrologic analyses can be very effective for the assessment of hydrologic effects of land use and climate changes, but the costs and expertise is often prohibitive. Progress has been made in four areas to reduce the costs and expertise required: (1) Watershed Data Management (WDM) system for the storage and retrieval of data used and generated by the model, (2) an expert system for the calibration of the model, (3) use of Geographical Information Systems to generate distributed parameters for the model, and (4) easy to use software for applications of the model.

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