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Full-Text Articles in Engineering
Preventing Pesticide Contamination Of Groundwater While Maximizing Irrigated Crop Yield, Richard C. Peralta, M. A. Hegazy, G. Musharrafieh
Preventing Pesticide Contamination Of Groundwater While Maximizing Irrigated Crop Yield, Richard C. Peralta, M. A. Hegazy, G. Musharrafieh
Civil and Environmental Engineering Faculty Publications
A simulation/optimization model is developed for maximizing irrigated crop yield while avoiding unacceptable pesticide leaching. The optimization model is designed to help managers prevent non-point source contamination of shallow groundwater aquifers. It computes optimal irrigation amounts for given soil, crop, chemical, and weather data and irrigation frequencies. It directly computes the minimum irrigated crop yield reduction needed to prevent groundwater contamination. Constraint equations used in the model maintain a layered soil moisture volume balance; describe percolation, downward unsaturated zone solute transport and pesticide degradation; and limit the amount of pesticide reaching groundwater. Constraints are linear, piecewise linear, nonlinear, and exponential. …
Optimizing Irrigation Management For Pollution Control And Sustainable Crop Yield, Ghassan R. Musharrafieh, Richard C. Peralta, Ronald J. Hanks, Lynn M. Dudley
Optimizing Irrigation Management For Pollution Control And Sustainable Crop Yield, Ghassan R. Musharrafieh, Richard C. Peralta, Ronald J. Hanks, Lynn M. Dudley
Civil and Environmental Engineering Faculty Publications
Irrigation strategies which maximize crop yield while maintaining target salt concentration in the root zone and/or prevent salt from leaching to the groundwater are computed using a nonlinear, one dimensional, simulation/optimization management model. The included constraint equations maintain a water volume balance and salt transport in the unsaturated zone. Utilized are implicit finite difference forms of the nonlinear, unsteady, unsaturated water flow equation (Richards's equation), and the diffusion-convection solute transport equation. Other constraints include nonlinear functions describing the hydraulic properties of the medium (hydraulic conductivity as a function of matric potential, volumetric water content as a function of matric potential, …