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Civil and Environmental Engineering Faculty Publications

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Articles 511 - 540 of 562

Full-Text Articles in Civil and Environmental Engineering

Measurement And Simulation Of One-Dimensional Transient Three Phase Flow For Monotonic Liquid Drainage, R. J. Lenhard, J. Dane, J. C. Parker, Jagath J. Kaluarachchi Jun 1988

Measurement And Simulation Of One-Dimensional Transient Three Phase Flow For Monotonic Liquid Drainage, R. J. Lenhard, J. Dane, J. C. Parker, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

Simultaneous movement of oil, water, and air in a sandy porous medium was investigated experimentally under transient flow conditions and results were compared to numerical simulations employing a finite element multiphase flow code. The liquid hydrocarbon was Soltrol 170, a low-density branched alkane mixture. Liquid saturations were measured using a collinear dual-energy gamma radiation apparatus and liquid pressures were measured using hydrophilic (untreated) and hydrophobic (treated) ceramic tensiometers connected to pressure transducers. The experimental regime was selected to impose monotonically draining water and total liquid saturation paths to avoid hysteretic effects. Measured saturations and pressures are compared to values obtained …

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Vilma (Virtually Interactive Large Scale Model For Arkansas), Rosalinda R.A. Cantiller, Richard C. Peralta Jan 1988

Vilma (Virtually Interactive Large Scale Model For Arkansas), Rosalinda R.A. Cantiller, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

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 …

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Effects Of Hysteresis With Air Entrapment On Water Flow In The Unsaturated Zone, Jagath J. Kaluarachchi, J. C. Parker Oct 1987

Effects Of Hysteresis With Air Entrapment On Water Flow In The Unsaturated Zone, Jagath J. Kaluarachchi, J. C. Parker

Civil and Environmental Engineering Faculty Publications

Effects of hysteresis with air entrapment on water content and head distributions, surface fluxes, and water balance components are investigated by finite element simulations of flow in one- and two-dimensional spatial domains. Results of one-dimensional analyses indicate that effects of hysteresis are markedly influenced by surface boundary conditions and to a lesser extent by initial conditions. Stipulation of flux-controlled boundary conditions results in minimal hysteretic effects, while potential-type boundary conditions produce substantial deviations between hysteretic and nonhysteretic simulations. The latter effects are attributable in large part to differences in surface conductivity associated with air entrapment. Predicted water content distributions for …

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Computational Aspects Of Chance‑Constrained Regional Modeling, R. R.A. Cantiller, Richard C. Peralta Jun 1987

Computational Aspects Of Chance‑Constrained Regional Modeling, R. R.A. Cantiller, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

A methodology that incorporates the stochasticity of an aquifer parameter in a chance-constrained steady-state groundwater management model is presented. Results and computational aspects of the modeling effort are discussed.

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Development Of Linear Water Quality Constraints For Optimal Groundwater Management, Richard C. Peralta, J. Solaimanian, S. A. Prathapar, C. L. Griffis Jun 1987

Development Of Linear Water Quality Constraints For Optimal Groundwater Management, Richard C. Peralta, J. Solaimanian, S. A. Prathapar, C. L. Griffis

Civil and Environmental Engineering Faculty Publications

Proposed is a procedure for incorporating solute transport as linear constraints within computer models for optimizing regional groundwater extraction strategies. . MODCON procedure uses linear goal programming. embedded linearized equations for flow and solute transport. and MOC simulation model. Assumed is 20 flow and solute transport. and a dispersed conservative contaminant.

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Expert Potentiometric Surface Modification For Groundwater Contaminant Management, R. L. Ward, Richard C. Peralta, J. R. Brashar Jun 1987

Expert Potentiometric Surface Modification For Groundwater Contaminant Management, R. L. Ward, Richard C. Peralta, J. R. Brashar

Civil and Environmental Engineering Faculty Publications

An expert system is linked to an previously reported optimization program. The expert system prompts the user for information about a groundwater contamination problem. The expert system determines whether pumping is a suitable containment strategy. If appropriate. it selects several well arrangements to be evaluated by an optimization algorithm.

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Maximizing Reliable Crop Production In A Dynamic Stream/Aquifer System, Richard C. Peralta, K. Kowalski, R. R.A. Cantiller Jun 1987

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

Reliable production of a dynamic stream/aquifer system is determined through an implicitly stochastic optimization model. Adequate representation of the inflow process and dynamic modeling of the stream/aquifer system results in optimum crop yield at specified reliability levels. Results include optimal spatial and temporal allocation of groundwater and diverted river water use. These can be used for planning cropping patterns and evaluating potential diversion systems.

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Development Of A Combined Quantity And Quality Model For Optimal Unsteady Groundwater Management, Richard C. Peralta, J. Solaimanian, C. L. Griffis, S. A. Prathapar Jun 1987

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

Civil and Environmental Engineering Faculty Publications

Presented is a procedure for incorporating solute transport as linear constraints within computer models for optimizing regional groundwater extraction strategies. The MODCON modelling procedure uses linear goal programming, embedded linearized equations for flow and solute transport and a MOC simulation model. Assumed is 20 flow and solute transport and a dispersed conservative contaminant. The MODCON procedure develops steady groundwater extraction strategies that will satisfy future groundwater quality constraints while simultaneously causing future piezometric heads to be as close to current heads as possible. The procedure is applied to a 160 square mile area in southeastern Arkansas.

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Finite Element Analysis Of Water Flow In Variably Saturated Soils, Jagath J. Kaluarachchi, J. C. Parker Apr 1987

Finite Element Analysis Of Water Flow In Variably Saturated Soils, Jagath J. Kaluarachchi, J. C. Parker

Civil and Environmental Engineering Faculty Publications

A two-dimensional Galerkin finite element model for water flow in variably saturated soil is presented. A fourth-order Runge-Kutta time integration method is employed which allows use of time steps at least 2 times greater than for a traditional finite difference approximation of time derivatives. For short total simulation times computer execution costs for the Runge-Kutta method are greater than for the finite difference approximation due to the start up cost of the Runge-Kutta method, but for longer simulation times the Runge-Kutta method requires considerably less computational effort even when automatic time-step adjustment is used with the finite difference procedure. A …

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Groundwater Recharge Planning Using Resolvent Discrete Kernels, Richard C. Peralta, Krzyzstof G. Kowalski, H. J. Morel-Seytoux Jan 1987

Groundwater Recharge Planning Using Resolvent Discrete Kernels, Richard C. Peralta, Krzyzstof G. Kowalski, H. J. Morel-Seytoux

Civil and Environmental Engineering Faculty Publications

No abstract provided.

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Decision Support For Optimal Regional Groundwater Management Strategy Modification, Richard C. Peralta, Paul J. Killian Jan 1987

Decision Support For Optimal Regional Groundwater Management Strategy Modification, Richard C. Peralta, Paul J. Killian

Civil and Environmental Engineering Faculty Publications

An interactive decision support program is presented for the rapid modification of optimal regional multiobjective groundwater planning strategies. This capability is important for water managers seeking to select the most satisfactory groundwater management strategies for their areas. The program guides decision maker(s) in refining numerically optimal regional strategies into strategies that may be socially or politically more acceptable. Strategy refinements are made by informed modification of constraining conditions on regional objectives or local variables. Application is illustrated by. modifying a bi criterion, sustained groundwater Withdrawal strategy for minimizing the cost of meeting regional water demand on the Arkansas Grand Prairie, …

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Managing Artificial Groundwater Recharge, Richard C. Peralta, K. G. Kowalski, H. J. Morel-Seytoux Dec 1986

Managing Artificial Groundwater Recharge, Richard C. Peralta, K. G. Kowalski, H. J. Morel-Seytoux

Civil and Environmental Engineering Faculty Publications

Increase in maximum groundwater mining resulting from recharge basin usage in the Grand Prairie is reported. Management model incorporates new influence coefficients that describe effect on groundwater levels of simultaneously' occurring basin/aquifer interflow and groundwater extraction.

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Optimal Groundwater Mining Methods, Richard C. Peralta, Krzysztof G. Kowalski Dec 1986

Optimal Groundwater Mining Methods, Richard C. Peralta, Krzysztof G. Kowalski

Civil and Environmental Engineering Faculty Publications

No abstract provided.

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Water Management: Making Sure Everyone Gets A "Reasonable" Share, Richard C. Peralta Sep 1986

Water Management: Making Sure Everyone Gets A "Reasonable" Share, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

No abstract provided.

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Infiltration Into Decomposed Granite Soils; Numerical Modeling, Applications And Some Laboratory Observations, A. W. Jayawardena, Jagath J. Kaluarachchi May 1986

Infiltration Into Decomposed Granite Soils; Numerical Modeling, Applications And Some Laboratory Observations, A. W. Jayawardena, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

This paper describes the outcome of a study on rain infiltration into decoposed granite which is one of the two main types of soils found in Hong Kong. It consists of the development and verification of a finite element based numerical model which has general applicability for flow through unsaturated porous media, application of the model for predicting moisture movement in an artificial slope made out of reconstituted decomposed granite and some laboratory observations including the estimation of soil hydraulic parameters.

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Optimizing The Rapid Evolution Of Target Groundwater Potentiometric Surfaces, Richard C. Peralta, Krzysztof G. Kowalski Jan 1986

Optimizing The Rapid Evolution Of Target Groundwater Potentiometric Surfaces, Richard C. Peralta, Krzysztof G. Kowalski

Civil and Environmental Engineering Faculty Publications

THE long-term availability of adequate groundwater for sustainable irrigated agricultural production can be assured by causing the evolution and maintenance of an appropriate potentiometric (piezometric) surface in utilized aquifers. By providing adequate saturated thickness and hydraulic gradients and heads. such a surface affords some protection from the effects of drought. economic: hardship, and environmental or legal complications. Procedures for determining desirable or optimal regional steady-state groundwater potentiometric surfaces have been reported by several researchers. An existing polcmiometric surface can be forced to evolve into a desirable 'target' surface if it is subjected through time to the proper combination of recharges …

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Sustained Groundwater Yield And Conjunctive Use Via Target Levels In A Reasonable Use State, Ann W. Peralta, Richard C. Peralta Jan 1986

Sustained Groundwater Yield And Conjunctive Use Via Target Levels In A Reasonable Use State, Ann W. Peralta, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

No abstract provided.

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Optimal Piezometric Surface Management For Groundwater Contaminant Control, Richard C. Peralta, R. L. Ward Jan 1986

Optimal Piezometric Surface Management For Groundwater Contaminant Control, Richard C. Peralta, R. L. Ward

Civil and Environmental Engineering Faculty Publications

A methodology is described for efficiently evaluating possible injection/extraction pumping schemes to most economically contain a groundwater contaminant plume. A multi-objective model is analyzed with a micro-computer. Simulation and optimization is performed by employing the response matrix method.

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Potential Arkansas And White Rivers Water Available For Diversion To The Grand Prairie, W. Douglass Dixon, Richard C. Peralta Jan 1986

Potential Arkansas And White Rivers Water Available For Diversion To The Grand Prairie, W. Douglass Dixon, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

At the present time. the rate of groundwater use in the Grand Prairie region of Arkansas exceeds natural replenishment of the underlying aquifer. Most of the groundwater is used for agricultural production. [f current agricultural water needs of the region are to be satisfied under sustained yield conditions. supplemental surface water will be required. The objective of this study is to assess the viability of the Arkansas and White Rivers as sources of supplemental water for meeting water needs in excess of those which can be met with groundwater.

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Assuring Sustained Groundwater Availability And Achieving Conjunctive Water Management By Target Approaches, Richard C. Peralta, Ann W. Peralta Jan 1986

Assuring Sustained Groundwater Availability And Achieving Conjunctive Water Management By Target Approaches, Richard C. Peralta, Ann W. Peralta

Civil and Environmental Engineering Faculty Publications

No abstract provided.

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Maintaining Target Groundwater Levels Using Goal‑Programming: Linear And Quadratic Methods, Amin Yazdanian, Richard C. Peralta Jan 1986

Maintaining Target Groundwater Levels Using Goal‑Programming: Linear And Quadratic Methods, Amin Yazdanian, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Sustained-yield groundwater management strategies can be designed to closely maintain preassigned 'target' levels. Quadratic and linear goal-programming objective functions are used in two distinct models which minimize the sum of differences between 'target' and regionally optimized sets of groundwater levels. Constraints and bounds imposed on extractions, recharge and heads in each model assure that developed strategies are physically feasible and sustainable. The linear model is computationally more time-efficient, but numerical difficulties due to equality constraints are encountered when it is applied to large groundwater systems_ The quadratic model requires less computer storage and is applied to the Grand Prairie of …

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Optimal Modification Of Regional Potentiometric Surface Design For Groundwater Contaminant Containment, Bithin Datta, Richard C. Peralta Jan 1986

Optimal Modification Of Regional Potentiometric Surface Design For Groundwater Contaminant Containment, Bithin Datta, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

A procedure for optimal modification of a regional potentiometric surface designed solely on the basis of quantitative considerations, is presented. The modification in the potentiometric surface is necessary to incorporate groundwater quality criteria in a critical subsystem of the entire region. The resulting optimal regional potentiometric surface ensures: sustained groundwater yields from the aquifer, compliance with water quality constraints at critical cells of the sub· system (which are identified by a solute transport simulation model), and the most economic conjunctive management of surface and groundwater.

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Interactive Modification Of Quadratic Multiobjective Water Resources Planning Strategies, Paul J. Killian, Richard C. Peralta Dec 1985

Interactive Modification Of Quadratic Multiobjective Water Resources Planning Strategies, Paul J. Killian, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

An interactive method is presented for modifying a mtltiobjective water resources planning strategy by changing constraining conditions on regional objectives and local variables. The method is illustrated by modifying a conjunctive use. sustained groundwater withdrawal strategy for minimizing the cost of meeting regional water demand on the Arkansas Grand Prairie. The strategy was developed using a model in which the finite difference form of the two-dimensional groundwater flow equation is embedded in an optimization process. The quadratic optimization is accomplished by utilizing the General Differential Algorithm to obtain values of drawdown. pumping. and recharge in each finite difference cell. Results …

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Future Quaternary Groundwater Accessibility In The Grand Prairie ‑ 1993, Richard C. Peralta, Amin Yazdanian, Paul J. Killian, Robert N. Shulstad Sep 1985

Future Quaternary Groundwater Accessibility In The Grand Prairie ‑ 1993, Richard C. Peralta, Amin Yazdanian, Paul J. Killian, Robert N. Shulstad

Civil and Environmental Engineering Faculty Publications

No abstract provided.

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Evaluating Water Policy Options By Simulation, Ann W. Peralta, Richard C. Peralta, Keyvan Asghari Jun 1985

Evaluating Water Policy Options By Simulation, Ann W. Peralta, Richard C. Peralta, Keyvan Asghari

Civil and Environmental Engineering Faculty Publications

Computer simulation models are used to predict the effects of three sample water policy decisions on selected conjunctive water use/sustained groundwater yield strategies for the Arkansas Grand Prairie. The three applications illustrate the facility of the target objective approach in providing an interface for legal, economic and engineering analysis. The approach is used to evaluate potential water management decisions at the judicial, legislative and water management district levels

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Conjunctive Use/Sustained Groundwater Yield Design, Richard C. Peralta Jun 1985

Conjunctive Use/Sustained Groundwater Yield Design, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Assuring the sustained availability of groundwater from all parts of an aquifer system is analogous to assuring that the potentiometric surface does not change over the long term. Such a steady-state surface is maintained by a specific spatially distributed pattern of groundwater withdrawal. The finite difference form of the linearized Boussinesq equation for steady two-dimensional flow through porous media is used in models that design optimal regional potentiometric surfaces and the conjunctive water use/sustained yield strategies that maintain them. Presented objectives of such models include minimization of unmet water needs. minimization of the regional cost of attempting to satisfy water …

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Regional Target Level Modification For Groundwater Quality, Bithin Datta, Richard C. Peralta Jun 1985

Regional Target Level Modification For Groundwater Quality, Bithin Datta, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

A procedure for modifying an optimal regional potentiometric surface designed solely on the basis of quantitative considerations, is described, These modifications are based on quality considerations in a sub-system of the-regional system. The affected changes in the water levels are shown to satisfy optimality criteria under specific conditions. An illustrative example is also provided

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Effect Of Rules And Laws On The Sustained Availability Of Groundwater, Richard C. Peralta, Paul Killian, Keyvan Asghari May 1985

Effect Of Rules And Laws On The Sustained Availability Of Groundwater, Richard C. Peralta, Paul Killian, Keyvan Asghari

Civil and Environmental Engineering Faculty Publications

No abstract provided.

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Potential Conjunctive Water Resources Use Plan For The Grand Prairie Region Of Eastern Arkansas, Ahmad Y. Ranjha, Richard C. Peralta, Amin Yazdanian Apr 1985

Potential Conjunctive Water Resources Use Plan For The Grand Prairie Region Of Eastern Arkansas, Ahmad Y. Ranjha, Richard C. Peralta, Amin Yazdanian

Civil and Environmental Engineering Faculty Publications

The main objective of this study is to develop two conjunctive water use strategies that can satisfy maximum potential irrigation water demand in the Grand Prairie region of Arkansas. for climatically average growing seasons. To accomplish this. the potential irrigation demand in each 3 mile x 3 mile cell of the study area is first determined on a monthly and seasonal basis for average climatic conditions. The potential demand is also calculated for dry climatic conditions. although these latter demand figures are not used in developing the potential conjunctive water use strategies.

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Development Of Optimal Sustained Yield Groundwater Withdrawal Strategies For The Boeuf‑Tensas Basin In Arkansas, Richard C. Peralta, Bithin Datta, Jamal Solaimanian, Paul J. Killian, Amin Yazdanian Jan 1985

Development Of Optimal Sustained Yield Groundwater Withdrawal Strategies For The Boeuf‑Tensas Basin In Arkansas, Richard C. Peralta, Bithin Datta, Jamal Solaimanian, Paul J. Killian, Amin Yazdanian

Civil and Environmental Engineering Faculty Publications

No abstract provided.

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