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Articles 961 - 990 of 1042

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

An Evaluation Of The Effect Of Discharging A High Quality Effluent Into A Small Ozark Mountain Stream, David G. Parker, Floyd E. Cotter, Sandra C. Parker Jun 1990

An Evaluation Of The Effect Of Discharging A High Quality Effluent Into A Small Ozark Mountain Stream, David G. Parker, Floyd E. Cotter, Sandra C. Parker

Arkansas Water Resources Center Technical Reports

Recently the newly constructed Fayetteville wastewater treatment plant went on line and directed a portion of its discharge to a point in the Mud Creek drainage basin that had previously not received any effluent. Prior to the discharge, a background study had been performed to establish the water quality in the basin. The background data, when compared to the data collected by this study, allowed any alteration of the stream water quality to be evaluated. Also the modeling procedure used to set the effluent limits for the treatment plant was analyzed. All stream data were compared to the limits set …


Fate Of Nitrogen From The Disposal Of Poultry Litter: A Simulation Approach, B. A. Ibrahim, H D. Scott Jun 1990

Fate Of Nitrogen From The Disposal Of Poultry Litter: A Simulation Approach, B. A. Ibrahim, H D. Scott

Arkansas Water Resources Center Technical Reports

A computer program was written to simulate the transport of nitrogen after an application of poultry litter to a pasture. The program was written in FORTRAN 77 to run on an IBM PC/AT or compatible personal computer or on a Sun SPARCSTATION. Simulation of water, solute and heat transport was by finite difference. Partition of rainfall into infiltration and runoff was by the SCS curve number method. A comparison was made of the computer model output with the results of a field experiment established at the Main Agricultural Experiment Station at Fayetteville. Poultry litter was applied at a rate of …


Virus Reduction By The Stanford Onsite Wastewater Treatment System, Mark A. Gross Jun 1990

Virus Reduction By The Stanford Onsite Wastewater Treatment System, Mark A. Gross

Arkansas Water Resources Center Technical Reports

A field study to examine the Stanford Onsite Wastewater Treatment System's ability to remove bacteriophage from wastewater was conducted. MS2 Coliphage was Injected Into the low pressure pipe (LPP) distribution system to achieve an Influent concentration of 1.6 x 106 plague forming units per milliliter (PFU/ml). The bacteriophage was Injected Into the system three times during the day, and samples were taken from drainage tiles of the treatment system. Tile drainage was assayed on conform bacteria host cultures for MS2 phage. The treatment system removed two to three logs (99% to 99.9%) of the phage. During the past two years, …


A Preliminiary Investigation To Determine The Economic Implications Of The "404" Permit For Constructing Agriculturally Related Reservoirs In Arkansas, Richard K. Ford, Charles R. Britton Jun 1990

A Preliminiary Investigation To Determine The Economic Implications Of The "404" Permit For Constructing Agriculturally Related Reservoirs In Arkansas, Richard K. Ford, Charles R. Britton

Arkansas Water Resources Center Technical Reports

A descriptive inquiry of the economic consequences of federal regulations which restrict the construction of agriculturally related reservoirs in Arkansas's wetlands is presented in this report. The applicable economic principles are identifyed and applied to the situation without the quantifiable information necessary to evaluate the alternatives. The difficulty of collecting the required quantifiable information necessitates the formulation of a different technique to unravel the dilemma. An alternative method for resolving the wetlands allocation question is presented for a public sector decision maker. This unconventional technique suggests that it may be desirable to estimate and compare the costs associated with the …


Optimal Reservoir Design Criteria In Conjuctive Use Of Surface Water And Groundwater For Soybean Irrigation In Eastern Arkansas, D. R. Edwards, J. A. Ferguson Jun 1990

Optimal Reservoir Design Criteria In Conjuctive Use Of Surface Water And Groundwater For Soybean Irrigation In Eastern Arkansas, D. R. Edwards, J. A. Ferguson

Arkansas Water Resources Center Technical Reports

A computer simulation model, named Arkansas Offstream Reservoir Analysis (ARORA) was developed to simulate present worth of net income from soybean production systems for conditions varying with respect to ground water availability, offstream reservoir capacity, and many other variables. Additional algorithms were incorporated into the model to enable it to optimize reservoir dimensions given realistic constraints and to identify the reservoir capacity corresponding to maximum present worth of simulated net income. The model was written in FORTRAN programming language and requires significant input data in order to provide significant flexibility with respect to the situations which may be accomodated. The …


Presentation Of Verified Algal Taxa As Reference Sources - Phase Ii, Richard L. Meyer Jun 1990

Presentation Of Verified Algal Taxa As Reference Sources - Phase Ii, Richard L. Meyer

Arkansas Water Resources Center Technical Reports

The focus of this research project was to continue the development of a photographic system which would record living organisms using various forms of light microscopy with correct color and with arrested movement. These demands dictate the use of an electronic flash source with metering and control system located in a position following the passage of the light through the optical train. The system developed uses off-the-shelf components with a modified flashtube holder which positions the tube in the axis of the light beam between the field and iris diaphragm. The light is measured off-the-film so that light from the …


Dew Chemistry, G. H. Wagner Jun 1990

Dew Chemistry, G. H. Wagner

Arkansas Water Resources Center Technical Reports

From July, 1989 to July 1990 a total of 98 dews and 9 frosts were collected at the University of Arkansas Agricultural Experiment Station, Fayetteville. The total water flux from dews and frosts per year is less than 2% of that from rains. Acid and nutrient fluxes are also much lower in dew. In the following series of ions the number in parenthesis gives the % of the yearly flux of the ion in dew compared to rain for an average year: H+ (0.08), Ca2+ (23), Mg2+(9), K+(20), Na+(5), NH+(12), Cl-(7), S02/4-(5) and N0-/3 (6). A typical dew has a …


Arkansas Water Resources Research Center Pamphlet, Kenneth F. Steele Jan 1990

Arkansas Water Resources Research Center Pamphlet, Kenneth F. Steele

Arkansas Water Resources Center Technical Reports

Arkansas Water Resources Center (AWRC) works closely with state and federal agencies and academic institutions. Priority research categories are: surface water analysis, ground water pollution, surface and ground water quality/quanity, and water resource management.


Calibration Of A General Optical Equation For Remote Sensing Of Suspended Sediments In A Moderately Turbid Estuary, Richard P. Stumpf, Jonathan Pennock Oct 1989

Calibration Of A General Optical Equation For Remote Sensing Of Suspended Sediments In A Moderately Turbid Estuary, Richard P. Stumpf, Jonathan Pennock

School of Marine Science and Ocean Engineering

Abstract

A general algorithm for determining suspended sediment concentrations in the surface waters of estuaries has been developed for use with satellite data. The algorithm uses a three-parameter general optical equation to relate suspended sediment concentrations to water reflectances that have been corrected for sun angle effects, atmospheric path radiance, and tidal excursion. Using data collected by the advanced very high resolution radiometer on five different dates, reflectances were determined using two different methods, one providing maximum correction for haze and the other providing minimum sensitivity to pigments. For both methods, in situ and remotely sensed samples from Delaware Bay …


Determining Pesticide And Nitrate Levels In Spring Water In Northwest Arkansas, T. L. Lavy, B. A. Dehart, John D. Mattice Jun 1989

Determining Pesticide And Nitrate Levels In Spring Water In Northwest Arkansas, T. L. Lavy, B. A. Dehart, John D. Mattice

Arkansas Water Resources Center Technical Reports

Occurrences of pesticides in our nations ground water are on the rise. As states become aware of this problem and begin monitoring programs, incidence of contamination will probably increase. Since the problem of pesticides in groundwater is relatively new, little research has centered on the fate of pesticides after they reach the groundwater environment. In Northwest Arkansas efforts to monitor groundwater for pesticides have been small. Twenty-five springs in Northwest Arkansas were sampled in the fall of 1988, and spring of 1989. Analysis for atrazine, alachlor, metolachlor, diuron, and simazine in spring water was preformed using gas liquid chromatography and …


Analysis, Design And Implementation Of A Pilot Relational Database For Groundwater In The State Of Arkansas, Ray Hashemi-Nassab Jun 1989

Analysis, Design And Implementation Of A Pilot Relational Database For Groundwater In The State Of Arkansas, Ray Hashemi-Nassab

Arkansas Water Resources Center Technical Reports

There are several agencies within the state of Arkansas dealing with underground water. Each agency has its own database that acts as an isolated depository of data. Practically, the communication among these databases is zero, not because there is no need for it, but because the communication is very difficult if not impossible. Data redundancy, inconsistency, and lack of integrity is overwhelming. In this study we have addressed the problem of lack of unity among the databases belonging to different agencies. Also, as an alternative we have developed a relational database. In this database the data was normalized to 4NF. …


An Expert System For Managing An Activated Sludge Wastewater Treatment Plant, Sandra C. Parker, David G. Parker Jun 1989

An Expert System For Managing An Activated Sludge Wastewater Treatment Plant, Sandra C. Parker, David G. Parker

Arkansas Water Resources Center Technical Reports

A diagnostic expert system for an activated sludge wastewater treatment plant has been designed to link with a relational database management system for obtaining operational parameter values that are used by the program to diagnose operational problems that may occur in the process. The problems that are dealt with by the system are bulking sludge, floating sludge, defloculation, ashing, solids washout, foaming problems, high soluble effluent BOD and problems in the aeration system. The link between the expert system and the database is accomplished via programming that is initiated by the expert system program. The operator of the system is …


Minimizing The Potential For Groundwater Contamination From Agricultural Point Sources, Joseph H. Massey, Terry L. Lavy, John D. Mattice Jun 1989

Minimizing The Potential For Groundwater Contamination From Agricultural Point Sources, Joseph H. Massey, Terry L. Lavy, John D. Mattice

Arkansas Water Resources Center Technical Reports

An activated charcoal filtration unit was designed to remove pesticides from leftover pesticide solutions and rinsates generated under farm-like conditions. The system, fabricated for less than $1400 using readily available components, effectively removed the pesticides atrazine, benomyl, carbaryl, fluometuron, metolachlor, and trifluralin from wastewater generated on the University of Arkansas Agronomy Farm located in Fayetteville, AR. A total of 2253 L of wastewater were treated using the system. Of these 1768 L were generated from washing out the spray tank (rinsates) while 485 L stemmed from leftover pesticide solutions that were mixed, but not applied. Typical initial pesticide concentrations in …


Improving Irrigation Scheduling And Water Use Efficiency In Cotton, Derrick M. Oosterhuis Jun 1989

Improving Irrigation Scheduling And Water Use Efficiency In Cotton, Derrick M. Oosterhuis

Arkansas Water Resources Center Technical Reports

Cotton (Gossypium hirsutum L) is an important crop in the southern United States. The crop is grown in both irrigated and rainfed situations and is seldom free from periods of water shortages at some stage during the season. In recent years the need for consistency in yields and a stable cash flow has resulted in a rapid expansion in the number of irrigated acres of cotton in the Mississippi Delta. Irrigation research has, however, not kept pace with this expansion. This project represents a start at meeting this urgent need. The influence of weather patterns necessitates that these studies be …


Simulation Of The Fate Of Nitrogen From The Disposal Of Poultry Litter, H. D. Scott Jun 1989

Simulation Of The Fate Of Nitrogen From The Disposal Of Poultry Litter, H. D. Scott

Arkansas Water Resources Center Technical Reports

A PC/AT computer model was developed to simulate the transport of water, nitrate and ammonia in the soil profile after an application of poultry litter to pasture. The model was written using FORTRAN 77 compiler and can be used on any IBM type compatible computer with a math coprocessor. Poultry litter has been shown to be a potential source of plant nutrients, but mismanagement can result in nitrate pollution of the surface and groundwater. The model is composed of a main program, 11 subroutines and three subprograms. An example was shown of the flexibility and dynamic nature of the computer …


Presentation Of Verified Algal Taxa As Reference Sources, Richard L. Meyer Jun 1989

Presentation Of Verified Algal Taxa As Reference Sources, Richard L. Meyer

Arkansas Water Resources Center Technical Reports

A data base of the algae of Arkansas ecoregions has been established to describe the numerous taxa that occur within the aquatic ecosystems included in these regions. The organisms were identified with the aid of diverse literature from throughout the world. These sources are written in multiple languages and the living organisms had to be compared with outline or silhouette drawings. These illustrations may include shading, but none present the true color of the organism but only the characteristics of the descriptive source. Primary characteristics used to identify algae is based upon pigmentation of the plastid and the number and …


Maine Nonpoint Source Pollution Assessment Report, Bureau Of Water Quality Control Jan 1989

Maine Nonpoint Source Pollution Assessment Report, Bureau Of Water Quality Control

Maine Collection

Maine Nonpoint Source Pollution Assessment Report

Prepared by the Maine Department of Environmental Protection, Bureau of Water Quality Control, Augusta, Maine 1989.

Contents: Executive Summary / Introduction / Methodology / Statewide Water Quality Summary / State And Local Agency Programs for Control of Nonpoint Source Pollution / Process for Identification of Best Management Practices and Associated Standards / List of References / List of Figures / List of Tables



Sulfide In Surface Waters Of The Western Atlantic Ocean, Gregory A. Cutter, Christian F. Krahforst Nov 1988

Sulfide In Surface Waters Of The Western Atlantic Ocean, Gregory A. Cutter, Christian F. Krahforst

OES Faculty Publications

Using newly developed techniques, some preliminary data on hydrogen sulfide in surface waters of the western Atlantic have been obtained. Concentrations of total sulfide range from <0.1 to 1.1 nmol/L, and vary on a diel basis. At these concentrations, sulfide may affect the cycling of several trace metals via the formation of stable complexes. Production of sulfide in oxygenated seawater may occur through the hydrolysis of carbonyl sulfide or by sulfate reduction within macroscopic particles in the water column. Removal mechanisms can include oxidation, complexation with particulate trace metals, and metal sulfide precipitation. However, the temporal and spatial distributions suggest a complex set of processes governing the behavior of sulfide in the surface ocean.


Virtually Interactive Large-Scale Model For Arkansas: User's Guide (Vilma), Rosalinda R. A. Cantiller, Richard C. Peralta Aug 1988

Virtually Interactive Large-Scale Model For Arkansas: User's Guide (Vilma), Rosalinda R. A. Cantiller, Richard C. Peralta

Arkansas Water Resources Center Technical Reports

This user’s guide supports the use of VILMA (Virtually Interactive Large-scale Model for Arkansas). This document presents the basic concepts in Chapter I. Chapter II discusses the execution steps that the user follows during a VILMA session. Chapter III provides a detailed illustration of example data files. Chapter IV presents two example VILMA sessions. Finally, Chapter V elaborates on additional concepts. The Appendices consist of relevant program listings, instructions, and example files. In this user’s guide, the word "interactive" means the user enters his responses to the prompts that appear on a computer terminal while he is logged on to …


Estimating Potential Ground And Surface Water Pollution From Land Application Of Poultry Litter - Ii, D. C. Wolf, J. T. Gilmour, P. M. Gale Jun 1988

Estimating Potential Ground And Surface Water Pollution From Land Application Of Poultry Litter - Ii, D. C. Wolf, J. T. Gilmour, P. M. Gale

Arkansas Water Resources Center Technical Reports

In Arkansas, approximately 1 Tg of poultry (Gallus gallus domesticus) manure and litter is produced annually. These waste products are commonly applied to pastures as a soil amendment or fertilizer, but excessive application rates and poor management practices could result in nutrient contamination of ground and surface water. The purpose of this study was to: (1) assess the nutrient concentrations in poultry manure and (2) evaluate the nitrogen loss from land-applied poultry litter and manure due to ammonia volatilization and denitrification. Analyses for total Kjeldahl nitrogen (TKN), inorganic nitrogen (Ni), phosphorus (P), and potassium (K) were compared in 12 wet …


Development Of A Combined Quantity And Quality Model For Optimal Management Of Unsteady Groundwater Flow Fields, R. C. Peralta, J. Solaimanian, C. L. Griffis Jun 1988

Development Of A Combined Quantity And Quality Model For Optimal Management Of Unsteady Groundwater Flow Fields, R. C. Peralta, J. Solaimanian, C. L. Griffis

Arkansas Water Resources Center Technical Reports

Presented are alternative techniques for including conservative solute transport within computer models for optimizing groundwater extraction rates. Unsteady two-dimensional flow and dispersed conservative solute transport are assumed. Comparisons are made of the practicality of including modified forms of implicit and explicit finite difference solute transport equations within optimization models. These equations can be calibrated and subsequently used within a MODCON procedure. The MODCON modelling procedure consists of an integrated series of five optimization or simulation modules. The procedure is applicable for either an entire aquifer system or for a subsystem of a larger system. The first module, A, computes physically …


Qualitative And Quantitative Aquatic Algal Data Compilation To Determine Macrotrends - Iv, Richard L. Meyer Jun 1988

Qualitative And Quantitative Aquatic Algal Data Compilation To Determine Macrotrends - Iv, Richard L. Meyer

Arkansas Water Resources Center Technical Reports

A data base of the algae of Arkansas ecoregions has been estabblished by the use of a relational data base management system (dBase III plus). The system was chosen to be readily available for a variety of microcomputers using MS- and PC-DOS. The data base contains taxonomic fields from division through variety, synonymy, authors, initial description, date, and definitive descriptive source. The data are cross-referenced by ecoregion, Round's community and subcommunity designations. The data base contains greater than 1,500 taxonomic records in all divisions and classes of freshwater algae. The data are sortable by any of the included parameters. The …


Long-Term Reconstruction And Analysis Of White River Streamflow, M. K. Cleaveland, D. W. Stahle, J. G. Hehr Jun 1988

Long-Term Reconstruction And Analysis Of White River Streamflow, M. K. Cleaveland, D. W. Stahle, J. G. Hehr

Arkansas Water Resources Center Technical Reports

A 281-year reconstruction of White River annual runoff at Clarendon, Arkansas, was developed from a regional average of nine Oklahoma, Missouri, and Arkansas tree-ring chronologies (six post oak, Quercus stellata, and three baldcypress, Taxodium distichum). Inhomogeneity of the gaged series was detected with both double mass analysis (using state average total annual Arkansas precipitation) and regression (using the regional tree-ring average). Simple regression calibrated the homogeneous runoff data with the average ring width data from 1930 to 1980. Comparing the reconstruction with independent data verified the regression model. Variance of the reconstruction increases significantly during the 20th century, a change …


Drought Management: The Role Of Near- Real Time Weather Data, Donald A. Wilhite, Kenneth G. Hubbard Jan 1988

Drought Management: The Role Of Near- Real Time Weather Data, Donald A. Wilhite, Kenneth G. Hubbard

National Drought Mitigation Center: Faculty Publications

The ability to collect weather data in near-real time has improved because of technological advances, enabling weather data users to obtain more weather data over wider areas, and in a more timely fashion. The number of near-real time climate networks is increasing as new applications are found for climate data. More than fifteen states in the United States have established automated weather station networks. This paper presents an overview of recent developments in automated weather data collection in the United States and gives a detailed description of the network in Nebraska.

Near-real time weather data has many applications in agricultural …


Cropstatus--A Computer Program To Assess The Effects Of Seasonal Weather Changes On Nebraska's Agriculture, R. E. Neild, Donald A. Wilhite, K. G. Hubbard Jan 1988

Cropstatus--A Computer Program To Assess The Effects Of Seasonal Weather Changes On Nebraska's Agriculture, R. E. Neild, Donald A. Wilhite, K. G. Hubbard

National Drought Mitigation Center: Faculty Publications

CROPSTATUS is a series of programs residing in Nebraska's AGNET system using daily weather data to assess seasonal changes in crops, livestock, and other agricultural conditions. Assessments are based on parameters developed from accumulations of current daily temperature and precipitation data collected from a network of synoptic, climate, and automated micrometeorological stations in Nebraska in comparison with daily normals. The daily normals were derived from monthly summaries using multiple regression models to compute daily values as a function of Julian day numbers. Crop phenology models based on growing degree days were used to monitor and forecast the progress of different …


Improving Projected Potential Evapotranspiration Estimates Using National Weather Service Forecasts, Steven J. Meyer, Kenneth G. Hubbard, Donald A. Wilhite Jan 1988

Improving Projected Potential Evapotranspiration Estimates Using National Weather Service Forecasts, Steven J. Meyer, Kenneth G. Hubbard, Donald A. Wilhite

National Drought Mitigation Center: Faculty Publications

In a recent survey conducted by the University of Nebraska's Center for Agricultural Meteorology and Climatology of Agricultural Network (AGNET) users, the results of potential evapotranspiration (ETp) projections (calculated using the Blaney-Criddle approach, which employs "normal" climatic data to project ETp estimates up to three days into the future) were labeled "unrealistic." To improve these projections, National Weather Service (NWS) forecast variables were used as input into the Blaney-Criddle and Penman equations. ETp projections calculated according to the Penman equation, with data measured by automated weather stations as input, were assumed to represent the "best" …


Soil Factors Affecting Flood Runoff On Agricultural Catchments In Western Australia, D J. Mcfarlane, J R. Davies Jan 1988

Soil Factors Affecting Flood Runoff On Agricultural Catchments In Western Australia, D J. Mcfarlane, J R. Davies

Resource management technical reports

Reviews methods of including soil properties in flood runoff-predicting equations. Concentrates on practical methods that can be routinely used by soil conservation technicians for flood prediction rather than complex research models. A case is made for collecting soil data from the gauged catchments which are relevant to a perceived runoff mechanism and are capable of being routinely applied in simple flood prediction methodologies.


The Nebraska Agricultural Climate Situation Committee, R. E. Neild, K. G. Hubbard, Donald A. Wilhite Jan 1988

The Nebraska Agricultural Climate Situation Committee, R. E. Neild, K. G. Hubbard, Donald A. Wilhite

National Drought Mitigation Center: Faculty Publications

The Nebraska Agricultural Climate Situation Committee consisting of an interdisciplinary group of extension specialists provides up-to-date information and advice on seasonal changes in crop/ weather conditions. The committee meets each Monday during the growing season to review:

1. Maps and tabular data developed by a computer program CIS /Crop Weather Information System/ that is linked to a network of weather stations and computer terminals in county agent offices.

2. Insect, plant disease and weed surveys.

3. Weekly weather and crop reports from the State/Federal System.

4. Weather outlooks from the National Weather Service.

5. Climate probabilities.

Situation reports and advisories …


A Preliminary Study Of The Hydrogeology Of The Dakota Formation In Douglas, Sarpy And Washington Counties, Eastern Nebraska, Thomas Mark O'Connor Aug 1987

A Preliminary Study Of The Hydrogeology Of The Dakota Formation In Douglas, Sarpy And Washington Counties, Eastern Nebraska, Thomas Mark O'Connor

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

This study provides preliminary information on the hydrogeology of the Dakota Formation within a 1,000 square-mile area in eastern Nebraska. Isopach maps of the Dakota Formation and individual sand and gravel beds were constructed using a computer contouring program. Hydraulic conductivity values for water-bearing sand beds in the Dakota were estimated using the equation for calculating the specific capacity of wells and results from a grain-size analysis. Concentrations of major dissolved species were determined for samples collected from twenty five wells. The Dakota Formation is characterized by an increase in thickkness and an increase in percentage of clay versus sand …


Assessment Of The Effects Of Household Chemicals Upon Individual Septic Tank Performances, Mark A. Gross Jun 1987

Assessment Of The Effects Of Household Chemicals Upon Individual Septic Tank Performances, Mark A. Gross

Arkansas Water Resources Center Technical Reports

A laboratory study and a field study were performed to determine the amounts of specific household chemicals required to destroy bacteria populations in individual domestic septic tanks. The particular chemicals evaluated include liquid chlorine bleach, High Test Hypochlorite (HTH), Lysol disinfectant and Drano crystal. The laboratory study was performed to determine the approximate chemical concentrations to destroy the bacteria in the septic tank, and the field study showed the actual effect of the chemicals upon the bacteria in terms of reduction of the number of bacteria in the septic tank as well as the time required for the bacterial population …