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Full-Text Articles in Engineering
Comparing Simulated And Experimental Hysteretic Two-Phase Transient Fluid Flow Phenomena, R. J. Lenhard, J. C. Parker, Jagath J. Kaluarachchi
Comparing Simulated And Experimental Hysteretic Two-Phase Transient Fluid Flow Phenomena, R. J. Lenhard, J. C. Parker, Jagath J. Kaluarachchi
Civil and Environmental Engineering Faculty Publications
A hysteretic model for two-phase permeability (k)-saturation (S)-pressure (P) relations is outlined that accounts for effects of nonwetting fluid entrapment. The model can be employed in unsaturated fluid flow computer codes to predict temporal and spatial fluid distributions. Consideration is given to hysteresis in S-P relations caused by contact angle, irregular pore geometry, and nonwetting fluid entrapment effects and to hysteresis in k-Srelations caused by nonwetting fluid entrapment effects. An air-water flow experiment is conducted with a 72-cm vertical soil column where the water table is fluctuated to generate scanning S-P paths. Water contents are measured via a gamma radiation …
Optimal Sustained-Yield Groundwater Pumping Strategy For The East Shore Area, Utah, Shu Takahashi, Richard C. Peralta
Optimal Sustained-Yield Groundwater Pumping Strategy For The East Shore Area, Utah, Shu Takahashi, Richard C. Peralta
Civil and Environmental Engineering Faculty Publications
Optimal sustained-yield pumping strategies were developed for the irrigated and industrialized eastern shore of the Great Salt Lake. The combined optimization and simulation model contains steady-state, finite difference, quasi-three-dimensional, groundwater flow equations embedded as constraints. The model computes the optimal spatial distribution of sustainable annual groundwater pumping rates for alternative scenarios. The addressed aquifer is a multilayer and confined/unconfined (linear/nonlinear) system. The research can help manage water in the study area, where the demand for water of sufficient quality and quantity is increasing due to urbanization.
Effects Of Alternative Sprinkler Irrigation Parameters On Pesticide Movement, Ahmad Yar Ranjha, Richard C. Peralta, Robert W. Hill, Antonio Maria Requena, Howard M. Deer, Majid Ehteshami
Effects Of Alternative Sprinkler Irrigation Parameters On Pesticide Movement, Ahmad Yar Ranjha, Richard C. Peralta, Robert W. Hill, Antonio Maria Requena, Howard M. Deer, Majid Ehteshami
Civil and Environmental Engineering Faculty Publications
The relative reduction in potential ground-water contamination due to pesticides at several sites in Utah was determined by comparing alternative irrigation system designs, water management practices and pesticides. Alternative sprinkler irrigation distribution coefficients were used to estimate infiltration depths. The movement of pesticides through soils following sprinkler irrigations was simulated with one-dimensional model. Pesticide contamination of ground water can be reduced by careful selection of pesticides, properly designed irrigation systems and improved water management techniques. Procedures for selecting an appropriate sprinkler design and pesticide are presented.
Assessing Pesticide Contamination To Groundwater: A Rapid Approach, Majid Ehteshami, Richard C. Peralta, Hubert Eisele, Howard M. Deer, Terry Tindall
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.
Sectar: Model For Economically Optimal Sustained Groundwater Yield Planning, Richard C. Peralta, K. Asghari, R. N. Shulstad
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 …