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Civil and Environmental Engineering Faculty Publications

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Articles 481 - 510 of 562

Full-Text Articles in Civil and Environmental Engineering

Sectar: Model For Economically Optimal Sustained Groundwater Yield Planning, Richard C. Peralta, K. Asghari, R. N. Shulstad Jan 1991

Sectar: Model For Economically Optimal Sustained Groundwater Yield Planning, Richard C. Peralta, K. Asghari, R. N. Shulstad

Civil and Environmental Engineering Faculty Publications

This paper presents an approach for computing economically optimal sustained yield ground-water extract ion strategies and supportable irrigated crop acreages. Computed regional strategies maximize the present value of net economic return_ They are useful for long-term agricultural planning because they are sustainable even beyond the planning period considered within the economic optimization. The hybrid approach uses only steady-state flow equations and iterative simulation/optimization to reduce optimization memory requirements below that required by conventional models utilizing both steady and unsteady equations. SECTAR, a quadratic optimization planning model assumes heads will evolve toward optimal steady-state but does initially not know the nonlinear …


Assessing Pesticide Contamination To Groundwater: A Rapid Approach, Majid Ehteshami, Richard C. Peralta, Hubert Eisele, Howard M. Deer, Terry Tindall Jan 1991

Assessing Pesticide Contamination To Groundwater: A Rapid Approach, Majid Ehteshami, Richard C. Peralta, Hubert Eisele, Howard M. Deer, Terry Tindall

Civil and Environmental Engineering Faculty Publications

A methodology has been developed for identifying hazardous pesticides/site combinations threatening ground-water contamination. Screening methodologies are required to determine which locations and pesticides now in use should receive the greatest attention to safeguard the public health. The presented method uses a hazard to ground-water hydrogeological screening model (DRASTIC) and employs a one-dimensional pesticide transport model ( CMLS). The method is an efficient and practical technique to identify where particular combinations of pesticides, water management practices, soils, and geology result in the greatest potential hazard to ground-water contamination. Use of the presented approach can reduce sampling needs and expense.


Comment On "On The Fractal Dimension Of Stream Networks" By Paolo La Barbera And Renzo Rosso, David G. Tarboton, Rafael L. Bras, Ignacio Rodriguez-Iturbe Sep 1990

Comment On "On The Fractal Dimension Of Stream Networks" By Paolo La Barbera And Renzo Rosso, David G. Tarboton, Rafael L. Bras, Ignacio Rodriguez-Iturbe

Civil and Environmental Engineering Faculty Publications

No abstract provided.


Pesticide Use On Utah's Crops, Howard M. Deer, Richard C. Peralta, Majid Ehteshami Sep 1990

Pesticide Use On Utah's Crops, Howard M. Deer, Richard C. Peralta, Majid Ehteshami

Civil and Environmental Engineering Faculty Publications

Utah State University's Cooperative Extension Service has placed high priority on a Water Quality Initiative for Utah. As a part of that emphasis, a research project was initiated to analyze the hazards that agricultural chemicals pose to Utah's ground water. The initial phase of this research was to determine those locations in Utah that are at greatest risk of ground water contamination by pesticides. This was accomplished by interfacing data on pesticide usage with soil and hydrologic factors. The results identified specific areas in the state where potential hazards exist. This report summarizes data on the use of pesticides on …


Use Of Simplex Algorithm For Optimizing Simulation Models, M. Ehteshami, L. S. Willardson, Richard C. Peralta Jun 1990

Use Of Simplex Algorithm For Optimizing Simulation Models, M. Ehteshami, L. S. Willardson, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

A methodology and computer model is developed to determine economically optimum closed subsurface drainage systems in irrigated areas. The mode 1 maximizes net benefits, by comparing profit driven by crop yields to drain system cost and selects an optimum drain layout. The optimization methodology used is the SIMPLEX method (Nelder and Mead, 1965). The SIMPLEX model was linked to the subsurface drainage model DRAINMOD (Skaggs, 1982) and to the surface hydraulic model KINE (Walker and Skogerboe 1987). The selected optimum drainage system maximizes the difference between total revenue, and the total cost of installation, operation and management of a particular …


Modelling For Potentiometric Surface Management Of Multilayer Aquifer Systems, A. Gharbi, Richard C. Peralta, K. M. Waddell Jun 1990

Modelling For Potentiometric Surface Management Of Multilayer Aquifer Systems, A. Gharbi, Richard C. Peralta, K. M. Waddell

Civil and Environmental Engineering Faculty Publications

Assuring the long-term availability of groundwater of adequate quality and quantity frequently requires the implementation of appropriate ground-water and conjunctive water management strategies. Presented is a model for developing optimal strategies for an multilayer aquifer in which stream-aquifer interflow is affected by the potentiometric surface and ground-water use. The model is applied to the Salt Lake Valley. Discussed is the use of pumping to control: l) potential migration of non-point source agricultural contaminants between aquifer layers and 2) the movement of a mile-long plume caused by mining waste.


Effects Of Alternative Furrow Irrigation Parameters On Pesticide Movement In Cropped Areas In Utah, Antonio Maria Requena, Ahmad Yar Ranjha, Richard C. Peralta, Howard M. Deer, Majid Ehteshami, Robert W. Hill Jun 1990

Effects Of Alternative Furrow Irrigation Parameters On Pesticide Movement In Cropped Areas In Utah, Antonio Maria Requena, Ahmad Yar Ranjha, Richard C. Peralta, Howard M. Deer, Majid Ehteshami, Robert W. Hill

Civil and Environmental Engineering Faculty Publications

Production of adequate supplies of food and fiber currently requires that pesticides be used to limit crop losses caused by insects, pathogens, weeds and other pests. Although pesticides are necessary in today' s agriculture, they can be a serious problem if they reach and contaminate ground water, especially where drinking water needs are met by ground water. The relative reduction of potential ground-water contamination due to agricultural use of pesticides was analyzed for particular sites in Utah. The potential reduction of pesticides in ground water was considered by utilizing alternative irrigation systems, water management practices and pesticides. A one-dimensional simulation …


Pesticide And Water Management Alternatives To Mitigate Potential Ground-Water Contamination For Selected Counties In Utah, Majid Ehteshami, Antonio M. Requena, Richard C. Peralta, Howard M. Deer, Robert W. Hill, Ahmad Yar Ranjha May 1990

Pesticide And Water Management Alternatives To Mitigate Potential Ground-Water Contamination For Selected Counties In Utah, Majid Ehteshami, Antonio M. Requena, Richard C. Peralta, Howard M. Deer, Robert W. Hill, Ahmad Yar Ranjha

Civil and Environmental Engineering Faculty Publications

Production of adequate supplies of food and fiber currently requires that pesticides be used to limit crop losses from insects, pathogens, weeds and other pests. Although pesticides are necessary in today's agriculture, they can be a serious problem if they reach and contaminate ground water, especially in places where drinking water needs are supplied from ground water. The relative reduction of potential ground-water contamination due to agricultural use of pesticides was analyzed for particular sites in Utah. The potential reduction of pesticides in ground water was considered by utilizing alternative irrigation systems, water management practices and pesticides. A one-dimensional simulation …


Modeling Of Multicomponent Organic Chemicaltransport In Three Phase Porous Media, Jagath J. Kaluarachchi, J. C. Parker May 1990

Modeling Of Multicomponent Organic Chemicaltransport In Three Phase Porous Media, Jagath J. Kaluarachchi, J. C. Parker

Civil and Environmental Engineering Faculty Publications

A two-dimensional finite-element model was developed to predict coupled transient flow and multicomponent transport of organic chemicals which can partition between nonaqueous phase liquid, water, gas and solid phases in porous media under the assumption of local chemical equilibrium. Gas-phase pressure gradients are assumed negligible and liquid flow equations are solved simultaneously using an upstream weighted solution method with time-lagged interphase mass-transfer terms and phase densities. Phase-summed component transport equations are solved serially after computation of the velocity field also by an upstream weighted finite-element method. Mass-transfer rates are evaluated from individual phase transport equations by back-substitution and corrected for …


A Numerical Model For Areal Migration Of Water And Light Hydrocarbon In Unconfined Aquifers, Jagath J. Kaluarachchi, J. C. Parker, R. J. Lenhard Mar 1990

A Numerical Model For Areal Migration Of Water And Light Hydrocarbon In Unconfined Aquifers, Jagath J. Kaluarachchi, J. C. Parker, R. J. Lenhard

Civil and Environmental Engineering Faculty Publications

A finite element model has been developed to simulate simultaneous flow of water and light hydrocarbon in an areal flow region of an unconfined aquifer for analyses of hydrocarbon spreading from subsurface leaks or spills and for use in design of free product recovery systems. Vertically integrated governing equations for water and oil flow are employed which assume local vertical equilibrium and negligible gas pressure gradients. Multiple water and free product recovery wells are handled as internal type-I boundary conditions by stipulating air-oil table elevation and free product height with corrections to convert grid averaged nodal heads to actual well …


Drastic Indices For Selected Agricultural Areas In Utah, Ahmad Yar Ranjha, Richard C. Peralta, Majid Ehteshami Mar 1990

Drastic Indices For Selected Agricultural Areas In Utah, Ahmad Yar Ranjha, Richard C. Peralta, Majid Ehteshami

Civil and Environmental Engineering Faculty Publications

The main objective of this report is to present contour maps of DRASTIC indices for selected areas in Utah. In general, the higher the DRASTIC index value, the greater the potential for ground-water pollution. The acronym DRASTIC is derived from the following hydrogeologic factors which affect vertical movement of water through the soil, and hence affect downward movement of contaminant.


The Policy Process: Cooperation As An Initiative In Utah, Richard C. Peralta, Ann W. Peralta Mar 1990

The Policy Process: Cooperation As An Initiative In Utah, Richard C. Peralta, Ann W. Peralta

Civil and Environmental Engineering Faculty Publications

No abstract provided.


Reconnaissance-Level Alternative Optimal Groundwater Use Strategies, Richard C. Peralta, Bithin Datta Jan 1990

Reconnaissance-Level Alternative Optimal Groundwater Use Strategies, Richard C. Peralta, Bithin Datta

Civil and Environmental Engineering Faculty Publications

This study develops regionally optimal ground-water extraction strategies. Alternative explicit planning objectives arc: (1) Maximize total pumping from the underlying aquifer while causing the evolution of a steady potentiometric: surface: and (2) maintain a prespecified target potentiometric surface. Implicit objectives involve controlling stream/aquifer interflow and water flow across a state boundary, and attempting to avoid poss disruption of current cropping patterns. Models, bounds, constraints, and data arc: formulated. Alternative optimal strategies and the rationale for preferring one strategy arc: presented for a region in Arkansas. The objective of maintaining the relatively unstressed target potentiometric: surl1ce yields politically and socially unacceptable …


Exeis, Expert Screening And Optimal Extraction/Injection Pumping Systems For Short-Term Plume Immobilization, R. L. Ward, Richard C. Peralta Jan 1990

Exeis, Expert Screening And Optimal Extraction/Injection Pumping Systems For Short-Term Plume Immobilization, R. L. Ward, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

This report presents the EXEIS family of micro-computer based programs for achieving short-term contaminant plume containment. EXEIS is applicable if contaminated water cannot be extracted and water cannot be imported to or exported from the site. There are two main purposes and types of users. For persons relatively unfamiliar with groundwater remedial actions, an expert screening system gives guidance concerning whether extraction/injection (Eli) pumping, slurry wall or sheet piling are most appropriate. For personal more experienced in remedial actions, management models compute optimal E/I strategies for short-term containment. Via deterministic and stochastic multiobjective optimization models, uncertainty in both planning horizon …


Optimal Conjunctive Use Of Ground And Surface Waters, Richard C. Peralta, A. Gharbi, L. S. Willardson, A. W. Peralta Jan 1990

Optimal Conjunctive Use Of Ground And Surface Waters, Richard C. Peralta, A. Gharbi, L. S. Willardson, A. W. Peralta

Civil and Environmental Engineering Faculty Publications

Conjunctive water management involves coordinating the use of groundwater and surface water in time and in space. The water sources might or might not be in hydraulic connection with each other. In this chapter, conjunctive water use involves the combined use of surface and groundwater to supply crop water needs.

Two simplified examples of conjunctive use follow. Farmer Allen uses river water to irrigate his crops. In dry years, with below average stream flow, his surface water supply is severely limited by late summer. To augment this surface water supply, he pumps groundwater. In wet years, when the surface water …


Conjunctive Water Use/Sustained Groundwater Yield Planning: Case History, A. R. Yar, Richard C. Peralta Jan 1990

Conjunctive Water Use/Sustained Groundwater Yield Planning: Case History, A. R. Yar, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

A methodology for computing perennial ground-water yield and conjunctive water use strategies is presented, using the Arkansas Grand Prairie as a case study. This includes development and use of an optimization model for computing sustainable ground-water pumping strategies and a post-processor for allocating ground-water and surface water supplies in time and space. The optimization model utilizes embedded finite difference flow equations as constraints and bounds on pumping, recharge and potentiometric head. Computed conjunctive use strategies will maintain, as much as possible, the existing stressed potentiometric surface. They will also assure at least 6 meters of saturated thickness in all locations …


Noninteractive Macroscopic Reliability Model For Ceramic Matrix Composites With Orthotropic Material Symmetry, Stephen F. Duffy, Jane M. Manderscheid Dec 1989

Noninteractive Macroscopic Reliability Model For Ceramic Matrix Composites With Orthotropic Material Symmetry, Stephen F. Duffy, Jane M. Manderscheid

Civil and Environmental Engineering Faculty Publications

A macroscopic noninteractive reliability model for ceramic matrix composites is presented. The model is multiaxial and applicable to composites that can be characterized as orthotropic. Tensorial invariant theory is used to create an integrity basis with invariants that correspond to physical mechanisms related to fracture. This integrity basis is then used to construct a failure funciton per unit volume (or area) of material. It is assumed that the overall strength of the composite is governed by weakest link theory. This leads to a Weibull type model similar in nature to the principle of independent action (PIA) model for isotropic monolithic …


Pesticide Movement And Water Management, Majid Ehteshami, Richard C. Peralta Oct 1989

Pesticide Movement And Water Management, Majid Ehteshami, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Agricultural chemicals are essential components of agricultural production systems in the United states. Pesticides control weeds, insects, and have had an important role in increasing agricultural productivity in the last 50 years, despite diminishing crop land acreage. The benefits of chemicals use options in agriculture must be balanced against potential contamination of surface water and ground water resources. This study shows the effect of water management practices on pesticide movement and its potential pollution to ground water. It indicates that careful use of pesticides, water management practices and irrigation system design alternatives could cause a major reduction in ground water …


Water Resources Development Alternatives For The Mississippi Alluvial Plain In Eastern Arkansas, Gary L. Mahon, John E. Terry, Richard C. Peralta Sep 1989

Water Resources Development Alternatives For The Mississippi Alluvial Plain In Eastern Arkansas, Gary L. Mahon, John E. Terry, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Effective management of the water resources of the Mississippi Alluvial Plain in eastern Arkansas involves understanding the nature of existing problems, estimating total water demands, predicting how much of the total demand can be provided by the underlying aquifer and available surface-water sources, and deducing how much water must come from alternate sources. Various Federal and State agencies have cooperatively provided hydrologic information for the area to evaluate water-resources development alternatives ensuring that (1) the use of water from the aquifer be maximized while maintaining a minimum of 20 feet of saturated thickness, (2) the use of surface water be …


Application Of Bmp For Prevention Of Ground-Water Contamination, Majid Ehteshami, Richard C. Peralta Sep 1989

Application Of Bmp For Prevention Of Ground-Water Contamination, Majid Ehteshami, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

The use of pesticides is an integral part of today's agriculture. In many cases, pesticides safeguard crops from severe pest infestation, or increase yield by suppressing competing weed growth. Pesticides often make the difference between profits and losses in farming operations. However, pesticides, even in extremely low concentrations, can pose a risk to human health and to the environment. Applied to plant or soil surfaces, or injected into the soil, pesticides may leach to the ground water or may be washed off with surface water. Pesticide contaminated surface water can reach ground water, or contaminated ground water can reach the …


On-Farm Reservoir Construction In The Grand Prairie Region Of Arkansas: An Engineering Economic Analysis, Jayson K. Harper, Richard C. Peralta, Robert N. Shulstad Jun 1989

On-Farm Reservoir Construction In The Grand Prairie Region Of Arkansas: An Engineering Economic Analysis, Jayson K. Harper, Richard C. Peralta, Robert N. Shulstad

Civil and Environmental Engineering Faculty Publications

No abstract provided.


Agricultural Pesticide Hazard To Groundwater In Utah, Hubert Eisele, Majid Ehteshami, Richard C. Peralta, Howard M. Deer, Terry T. Tindall Apr 1989

Agricultural Pesticide Hazard To Groundwater In Utah, Hubert Eisele, Majid Ehteshami, Richard C. Peralta, Howard M. Deer, Terry T. Tindall

Civil and Environmental Engineering Faculty Publications

We gratefully acknowledge the funding support of the Utah Department of Agriculture and the following offices at Utah State University. The Department of Agricultural and Irrigation Engineering, the International Irrigation Center, the Department of Animal, Dairy and Veterinary Sciences, the Department of Soil Science and Biometerology, and the University Extension Services.


Computational Aspects Of Chance-Constrained Sustained Groundwater Yield Management, R. R.A. Cantiller, Richard C. Peralta Mar 1989

Computational Aspects Of Chance-Constrained Sustained Groundwater Yield Management, R. R.A. Cantiller, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

A methodology for including chance-constraints in models for maximizing regional sustained-yield groundwater extraction is presented. The procedure utilizes the spatially distributed mean and variance of saturated thickness in a confined aquifer. This data is derivable from kriging, a geostatistical technique. The technique is applied to a scenario of somewhat egalitarian agricultural development dependent on groundwater. Decision makers in this situation know that groundwater availability is insufficient to supply all potential demand. They plan to implement a sustained yield groundwater extraction strategy. They know that because of uncertain knowledge of aquifer parameters, at some point in the future, available groundwater in …


Coordinating Institutional Approaches To Assure Sustainable Groundwater Of Adequate Quality And Quantity In Utah, Richard C. Peralta, A. W. Peralta, K. Wyatt, Robert W. Hill Jan 1989

Coordinating Institutional Approaches To Assure Sustainable Groundwater Of Adequate Quality And Quantity In Utah, Richard C. Peralta, A. W. Peralta, K. Wyatt, Robert W. Hill

Civil and Environmental Engineering Faculty Publications

Utah is an arid state, without the abundant surface water resources enjoyed by states in the humid east. Most precipitation in the state falls in the higher elevations of the Uinta and Wasatch mountains of northern and central Utah. Much of this precipitation ultimately ends up in alluvial deposits at the base of these ranges, from which the vast majority of pumping wells draw their water (Barnes and Croft, 1986). This groundwater is an essential resource for use by the people of Utah. About sixty-three percent of Utah's population is at least partially reliant on groundwater for domestic use. In …


Optimizing Short-Term Plume Containment: Comparison Of Well Arrangements., Herminio H. Suguino, Richard C. Peralta Jan 1989

Optimizing Short-Term Plume Containment: Comparison Of Well Arrangements., Herminio H. Suguino, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Three well configurations were compared in terms of term ground-water contaminant plume containment. include parallel, octagonal and combination systems. system had three extraction wells upqradient and injection wells downgradient of the contaminant plume.
For each system, optimal pumping values and resulting potentiometric surface smoothness were computed for a hypothetical plume. Tested models utilized linear programming optimization and simulation via the response matrix method.
The octagonal well configuration required less pumping for a pumping period of 8 days, than did the parallel or combination systems. The octagonal configuration resulted in the smoothest potentiometric surface, in terms of difference in final head …


Sstar Users Manual, Richard C. Peralta, P. W. Killian, A. Yazdanian, V. Kumar Jan 1989

Sstar Users Manual, Richard C. Peralta, P. W. Killian, A. Yazdanian, V. Kumar

Civil and Environmental Engineering Faculty Publications

There are four objective functions available to date (11/86), these include 1) maximimize total regional groundwater withdrawl. 2) minimize total coat of satisfying regional needs. and 3) maximize the sum of selected local withdrawls. and 4) maximize the present value of total net economic return.


Finite Element Model Of Nitrogen Species Transformation And Transport In The Unsaturated Zone, Jagath J. Kaluarachchi, J. C. Parker Nov 1988

Finite Element Model Of Nitrogen Species Transformation And Transport In The Unsaturated Zone, Jagath J. Kaluarachchi, J. C. Parker

Civil and Environmental Engineering Faculty Publications

A two-dimensional finite element model based on Galerkin's weighted residual approach and incorporating an upstream weighting technique was developed to predict the simultaneous transformation and transport of nitrogen species. The nitrogen cycle used in the analyses assumes first-order rate coefficients for nitrification, denitrification, immobilization and mineralization between the nitrogen species NH +4, NO -3, organic-N and denitrified fractions. The NO -3-N component in the soil solution was assumed to have negligible adsorption on exchange sites while adsorption of NH +4 was assumed to be represented by a Freundlich type nonlinear isotherm ( S = kdCp). The accuracy and validity of …


Development Of A Combined Quantity And Quality Model For Optimal Unsteady Groundwater Management, Richard C. Peralta, J. Solaimanian, C. L. Griffis Oct 1988

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

Civil and Environmental Engineering Faculty Publications

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 …


Maximizing Reliable Crop Production In A Dynamic Stream/Aquifer System, Richard C. Peralta, K. Kowalski, R. R.A. Cantiller Sep 1988

Maximizing Reliable Crop Production In A Dynamic Stream/Aquifer System, Richard C. Peralta, K. Kowalski, R. R.A. Cantiller

Civil and Environmental Engineering Faculty Publications

A procedure for planning the optimal spatial distribution of crops to be reliably irrigated by conjunctive use of water resources is presented. The implicitly stochastic procedure utilizes. simulation/ optimization model of • stream/ aquifer system. The model utilizes linear optimization, hydrologic influence coefficients and time-varying crop water production functions. It appropriately simulates the time variant, interdependent responses of groundwater levels, stream nap and stream/aquifer interflow to groundwater pumping, and diversion of river water to nonriparian lands. It determines the temporally and spatially varying distribution of groundwater and diverted river water that should be utilized In order to maximizing annual crop …


Optimal Conjunctive Use-Sustained Yield Pumping Analysis For Eastern Arkansas, Rosalinda R.A. Cantiller, Richard C. Peralta, Hossein Azarmnia Aug 1988

Optimal Conjunctive Use-Sustained Yield Pumping Analysis For Eastern Arkansas, Rosalinda R.A. Cantiller, Richard C. Peralta, Hossein Azarmnia

Civil and Environmental Engineering Faculty Publications

The likelihood that irrigated agricultural acreages will increase in eastern Arkansas is high. This results from favorable agricultural soils, climate, and the availability of significant water resources.