Physical Sciences and Mathematics Commons^™

The Effects Of Wet Meadow Fragmentation On Grassland Birds, Christopher J. Helzer

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Histomorphological Responses Of Red Shiner (Cyprinella Lutrensis) To Atrazine, Terbufos, And Their Mixture, Ibrahim A. Messaad

School of Natural Resources: Dissertations, Theses, and Student Research

Alterations of normal histomorphology of fish tissues, behavior, and thermal tolerance are recognized by environmental toxicologists and fish biologists as powerful tools indicating diverse biochemical and physiological changes. Toxicity of atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine), terbufos (S-(((1,1-dimethyl-ethyl)thio)methyl)O,O-diethyl phosphorodithioate), and their mixture to red shiner (Cyprinella lutrensis) at 23$\sp\circ$C and 30$\sp\circ$C was investigated in 14-d bioassays after 14-d acclimation. During the bioassays, fish behavior, indications of toxicosis, and external anomalies were observed. After the bioassays, the critical thermal maximum (CTM) was determined. Fish also were preserved for examinations of gill, liver, and kidney tissues using scanning electron microscopy (SEM) and light microscopy (LM). SEM …

Historical Biomass Burning: Late 19th Century Pioneer Agriculture Revolution In Northern Hemisphere Ice Core Data And Its Atmospheric Interpretation, G. Holdsworth, K. Hiuchi, G. A. Zielinski, Paul Andrew Mayewski, M. Wahlen, B. Deck, P. Chylek, B. Johnson, P. Damiano

Earth Science Faculty Scholarship

Ice core data from Yukon and Greenland spanning from ∼1750 to 1950 indicate that between ∼1850 and ≤1910 a clear atmospheric signal exists of an episodic biomass burning event that is referred to as the Pioneer Agriculture Revolution. This is best seen in NH₄⁺ ion and particulate concentrations but also in some limited black carbon concentration data, where for all three quantities maximum levels reach about 3 times the prerevolution background concentrations. Tree cellulose δ¹³C data and some early, controversial, French, air CO₂ data, occurring within the same time interval, are interpreted as providing other …

Impact Of Groundwater Contamination In East Multnomah County On The Interlachen Community, Scott A. Wells, Shuguang Li, Marvin Beeson, Michael Cummings, Richard Pratt, Robert Leslie Annear, Karann Brandt

Civil and Environmental Engineering Faculty Publications and Presentations

The Friends of Blue and Fairview Lake through the Environmental Protection Agency (EPA) Technical Assistance Grant (TAG) program contracted with Portland State University faculty and staff to provide an independent review of the groundwater contamination problem at the Boeing-Cascade site in East Multnomah County. An independent consultant, Karann Brandt, of PRC Environmental Management, Inc., was also assisting the panel with the review.

The region of groundwater contamination is a 2.5 square mile region bounded by NE Halsey Blvd. to the Columbia River and NE 178th to NE 223rd (see Figure 1). The groundwater contamination is primarily of volatile organic compounds …

Depletion Of Atmospheric Nitrate And Chloride As A Consequence Of The Toba Volcanic Eruption, Q. Yang, Paul Andrew Mayewski, G. A. Zielinski, M. Twickler, K. C. Taylor

Earth Science Faculty Scholarship

Continuous measurements of SO₄²⁻ and electrical conductivity (ECM) along the GISP2 ice core record the Toba mega‐eruption at a depth 2590.95 to 2091.25 m (71,000±5000 years ago). Major chemical species were analyzed at a resolution of 1 cm per sample for this section. An ∼6‐year long period with extremely high volcanic SO₄²⁻ coincident with a 94% depletion of nitrate and 63% depletion of chloride is observed at the depth of the Toba horizon. Such a reduction of chloride in a volcanic layer preserved in an ice core has not been observed in any previous studies. The …

Relationship Between Continuous Aerosol Measurements And Firn Core Chemistry Over A 10‐Year Period At The South Pole, M. H. Bergin, E. A. Meyerson, J. E. Dibb, Paul Andrew Mayewski

Earth Science Faculty Scholarship

Before ice core chemistry can be used to estimate past atmospheric chemistry it is necessary to establish an unambiguous link between concentrations of chemical species in the air and snow. For the first time a continuous long‐term record of aerosol properties (aerosol light scattering coefficient, σ_sp , and Ångström exponent, å) at the South Pole are compared with the chemical record from a high resolution firn core (∼10 samples per year) covering the period from 1981 to 1991. Seasonal signals in å, associated with winter minima due to coarse mode seasalt and summer maxima due to accumulation mode sulfate …

Chemical Species Spatial Distribution And Relationship To Elevation And Snow Accumulation Rate Over The Greenland Ice Sheet, Q. Yang, Paul Andrew Mayewski, E. Linder, S. Whitlow, M. Twickler

Earth Science Faculty Scholarship

Major chemical species (Cl⁻, NO⁻₃, SO²⁻₄, Na⁺, K⁺, Mg²⁺, Ca²⁺) from 24 snowpits (sampled at a resolution of 3 cm, total 2995 samples) collected from northern, central, and southern Greenland were used for this investigation. The annual and seasonal (winter and summer) concentration of each chemical species was calculated and used to study the spatial distribution of chemical species over the central portion of the Greenland Ice Sheet. A two-sided t-distribution test (α=0.05) suggests that concentrations of major chemical species in snow do …

Propogation Of Juniperus For Conservation Plantings In The Great Plains, Scott Allen Lee

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

The Biology Of Alewife Alosa Pseudoharengus In Lake Ogallala, Nebraska, Eric A. Laux

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Hydrostratigraphy And Allostratigraphy Of The Cenozoic Alluvium In The Northwestern Part Of Las Vegas Valley, Clark County, Nevada, David J. Donovan

UNLV Theses, Dissertations, Professional Papers, and Capstones

This investigation was conducted to determine the location, nature, and boundaries of the most permeable unit within the alluvial aquifer material in Las Vegas Valley. It was prompted by declines in specific capacity of about 90% at the Las Vegas Valley Water District's West Central Well Field. It was hypothesized that the decline in specific capacity resulted from dewatering of the most permeable interval of the alluvium. Lithologic descriptions from wells and aquifer test information were analyzed for geologic and hydrogeologic variability. New information, in the form of detailed unpublished lithologic and hydrologic information, was available from twenty water wells …

Influence Of Rice Production On The Quality Of Water In Tailwater Collection Reservoirs, R. A. Dewell, T. L. Lavy

Technical Reports

Since maintaining high water quality standards in the state remains a high priority, monitoring for pesticides in water sources must continue. Determining the type, concentration, and characteristics of any pesticides present in water supplies are essential to the overall assessment of water quality. Five independent locations, implementing contained water management systems and recyclable water, were monitored in 1995 and 1996. Irrigation, runoff, and pond water samples were collected every 10 to 14 days between permanent flood establishment and draining. Water samples were transported to the laboratory and extracted for 16 pesticides using solid phase extraction (SPE) techniques. Quantification and confirmation …

Bioaccumulation Of Methyl Mercury Through A Food Chain, J. T. Knight

Technical Reports

The bioaccumulation of mercury through the food chain has received much attention in Arkansas during the last three years. The discovery of mercury contamination and subsequent fish consumption advisories in southwest Arkansas have increased public awareness of the potential for bioaccumulation of different toxic compounds. It is postulated that the mercury problem in Arkansas is a result of methylation and resulting bioaccumulation of mercury as methyl mercury. This study was designed to derive a Bioaccumulation Factor (BAF) for mercury in a simple food chain under controlled conditions. A BAF is calculated by dividing the concentration found in the organism by …

Effects Of Zebra, Mussel, Dreissena Polymorpha Infestation On Lake Dardanelle Water Quality, Charles J. Gagen, Joseph N. Stoeckel

Technical Reports

Zebra mussels recently invaded southern waterways including the Arkansas River. Large-scale filtration of suspended particulate matter by dense populations could alter reservoir ecosystem function. Furthermore, they attach to hard surfaces, thereby threatening normal operations of artificial structures. We designed this study to provide baseline data prior to establishment of high population levels of zebra mussels in Lake Dardanelle. The characterization of spatial and temporal variability in water quality, zooplankton, phytoplankton, and macrophytes will allow testing of several hypotheses. We sampled zebra mussel veliger and settling juvenile densities and zooplankton densities at four fixed sites and the key water quality variables …

Modeling Transport Of Colloid-Bound Herbicides And Heavy Metals To Groundwater, Anastasios D. Karathanasis, R. E. Phillips, A. K. Seta

KWRRI Research Reports

Recent studies have suggested that contaminant transport to groundwater may be enhanced by association with colloidal particles. This study evaluated the role of water dispersible colloids with diverse mineralogical composition in co-transporting selected herbicides and heavy metals through intact soil columns. Colloid recovery in the eluents ranged from 45-90% for the herbicides and 10-60% for the heavy metals. The presence of colloids enhanced the transport of atrazine by 2-18%, and metolachlor by 8-30%. The corresponding increase for Cu and Zn was 2-150 and 5-30 times, respectively. For Pb, there was essentially no elution in the absence of colloids, suggesting nearly …

Twin Ice Cores From Greenland Reveal History Of Climate Change, More, R. Alley, Paul Andrew Mayewski, D. Peel, B. Stauffer

Earth Science Faculty Scholarship

Two projects conducted from 1989 to 1993 collected parallel ice cores—just 30 km apart— from the central part of the Greenland ice sheet. Each core is more than 3 km deep and extends back 110,000 years. In short, the ice cores tell a clear story: humans came of age agriculturally and industrially during the most stable climatic regime recorded in the cores. Change—large, rapid, and global—is more characteristic of the Earth's climate than is stasis.

Chronic Effects Of Baseflow Levels Of Atrazine On Platte River Algae, Karen J. Nelson

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Influence Of Prey Availability On Walleye (Stizostedion Vitreum), Mark T. Porath

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Growth And Yield Of Snap Beans (Phaseolus Vulgaris L.) As Affected By Shelterbelts And Planting Dates, Mohd Nazip Suratman

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Thermal Tolerances Of Platte River Fishes: Field And Laboratory Studies, Brett P. Fessell

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Residence Time Of Groundwater Issuing From The South Rim Aquifer In The Eastern Grand Canyon, Jim Fitzgerald

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the eastern Grand Canyon, secondary porosity created by north trending faults, folds, and breccia pipes, facilitates groundwater flow through the South Rim carbonate aquifer. Springs associated with the South Rim Aquifer have low ³H concentrations, [Ca²⁺]/[Mg²⁺] rations close to unity, and variable uranium concentrations. For a geochemical comparison, springs are subcategorized on the basis of geology and discharge. Type I springs are associated with high-angle normal faults and have high discharge rates. These springs discharge Ca²⁺ - Mg²⁺, HCO₃^- waters, have ³H concentrations <2 TR, and ²³⁴U/²³⁸U activity …

Trace Element Analysis Of Selected Springs In The Virgin River Basin, Mary A. Yelken

UNLV Theses, Dissertations, Professional Papers, and Capstones

Spring water from 23 springs in and near the Virgin River Basin (southwestern Utah, northwestern Arizona, and southeastern Nevada) was collected and analyzed for chemical concentrations. Trace elements and major ion chemistry was used to determine the potential for utilizing water chemistry to provide information on spring water source and flow pathways. Principal Component Analysis (PCA), rare earth element (REE) normalization patterns, and mineral equilibrium modeling (PHREEQE) techniques were used to analyze the data set. Four major spring water groups were displayed by the PCA, based on similarities in water chemistry. The analyses suggest that spring water chemistry is a …

Potential Atmospheric Impact Of The Toba Mega‐Eruption ∼71,000 Years Ago, G. A. Zielinski, Paul Andrew Mayewski, L. D. Meeker, S. Whitlow, M. S. Twickler, K. Taylor

Earth Science Faculty Scholarship

An ∼6‐year long period of volcanic sulfate recorded in the GISP2 ice core about 71,100 ± 5000 years ago may provide detailed information on the atmospheric and climatic impact of the Toba mega‐eruption. Deposition of these aerosols occur at the beginning of an ∼1000‐year long stadial event, but not immediately before the longer glacial period beginning ∼67,500 years ago. Total stratospheric loading estimates over this ∼6‐year period range from 2200 to 4400 Mt of H₂SO₄ aerosols. The range in values is given to compensate for uncertainties in aerosol transport. Magnitude and longevity of the atmospheric loading may …

A Century Of Accumulation And Temperature Changes In Dronning Maud Land, Antarctica, Elisabeth Isaksson, Wibjörn Karlén, Niels Gundestrup, Paul Andrew Mayewski, Sallie Whitlow, Mark Twickler

Earth Science Faculty Scholarship

A mass balance program was initiated in the Vestfjella-Heimefrontfjella area of western Dronning Maud Land during the austral summer of 1988–1989. As a part of this program, spatial and temporal variations in snow accumulation and temperature/stable isotopes are measured using shallow firn cores. In this paper we present surface accumulation data and discuss the climatic implications of the stable isotope records from two shallow firn cores. One 30-m-deep core, obtained about 200 km from the coast at 700 m asl (73°36′S, 12°26′W), covers the period 1932–1991. The other core was drilled at about 500 km from the coast at 2900 …

Flash-Flood Monitoring And Modeling In Kentucky, Mark French, Nageshwar Bhaskar, George K. A. Kyiamah

KWRRI Research Reports

This research project focused on the evaluation of hydrologic issue of flash-flooding in the state of Kentucky. The primary objectives of this project were the following:
(1) to initiate the establishment of a hydrologic database archive necessary for characterizing rainfall and runoff associated with flash-flooding;
(2) identification of appropriate modeling approaches for evaluating site-specific flash-flood runoff behavior.

Specific tasks accomplished to meet the objectives include the following:
(1) development of a rainfall and streamflow data archive using existing measurement gages and identification of the rain gage data from two sources for preliminary quality control;
(2) identification of the spatial and …

Geology Beneath The Primary Management Systems Evaluation Area (Msea) Site Southwest Of Shelton, Buffalo County, Nebraska, Robert F. Diffendal Jr., Frank A. Smith

Robert F. Diffendal, Jr., Publications

In 1990, as part of a national presidential initiative on water quality, researchers from the University of Nebraska–Lincoln (UNL) Institute of Agriculture and Natural Resources (IANR) received a multiyear grant from the U.S. Department of Agriculture, Cooperative State Research Service, to study management of irrigated corn and soybeans to minimize groundwater contamination. D. G. Watts, R. F. Spalding, and J.S. Schepers, of the IANR led a study at one of the Management Systems Evaluation Areas (MSEA). This area was made up of two sites, a primary site on a terrace of the Platte River near Shelton and a secondary site …

Ice-Core Glaciochemical Reconnaissance In Inland West Antarctica, Karl J. Kreutz, Paul Andrew Mayewski, Mark S. Twickler, Sallie I. Whitlow

Earth Science Faculty Scholarship

To date, the highest resolution ice cores have come from Greenland [the U.S. Greenland Ice Sheet Project 2 (GISP2) and European Greenland Ice Core Project (GRIP)]. The ability to determine annual layering in these cores over at least the past 50,000 years has allowed the reconstruction of a detailed environmental history covering major glacial and interglacial climatic events (e.g., Mayewski et aI. 1994; O'Brien et al. 1995). Although these cores have significantly advanced our understanding of paleoclimatic change in the Northern Hemisphere, questions remain as to whether the two hemispheres have responded synchronously to climate forcing through time. Determining the …

Comparison Of Daily Water Table Depth Prediction By Four Simulation Models, Eric D. Desmond, Andrew D. Ward, Norman R. Fausey, Stephen R. Workman

Biosystems and Agricultural Engineering Faculty Publications

The Agricultural Drainage And Pesticide Transport (ADAPT) model was compared to the water management simulation models DRAINMOD, SWATREN, and PREFLO. SWATREN and PREFLO are one-dimensional finite-difference models while ADAPT and DRAINMOD are one-dimensional mass balance models. ADAPT, an extension of the computer model GLEAMS, also provides chemical transport information. All four models were tested against field data from Aurora, North Carolina. Observed water table depth data were collected during 1973 through 1977 from a water table management field experiment with three subsurface drain spacing treatments of 7.5, 15, and 30 m.

Both the standard error of estimate and the average …

Salinity Action Plan, Department Of Agriculture And Food, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

In November, the Premier of Western Australia, Richard Court, released his governments strategy to tackle one of the State's most serious environmental problems - salinity. This article provides a summary of the action plan, full details are available in a two volum set 'Salinity - a situation statement for Western Australia' and 'Western australian salinity action plan'.

Copies of the reports are available from Publication Section, Agriculture Western Australia, 3 Baron-Hay Court, South Perth 6151. Phone (09) 368 3729

Hydrogeology, Hydrogeochemistry, And Spoil Settlement At A Large Mine-Spoil Area In Eastern Kentucky: Star Fire Tract, David R. Wunsch, James S. Dinger, Page B. Taylor, Daniel I. Carey, C. Douglas R. Graham

Report of Investigations--KGS

An applied research program at the Star Fire surface mine in eastern Kentucky, owned and operated by Cypress-AMAX Coal Co., defined spoil characteristics to develop and monitor water resources, which will help identify a reliable water supply for future property development. Water stored in the mine spoil may provide a usable ground-water supply, and the spoil could also be engineered to provide base flow to surfacewater reservoirs.

Ground-water recharge enters the spoil by way of sinking streams, ground-water flow from bedrock in contact with the mine spoil, and a specially designed infiltration basin. Ground water discharges predominantly from springs and …

Burt County Test Hole Logs, Raymond R. Burchett, Frank A. Smith

Conservation and Survey Division

No abstract provided.