HR: 1340h
AN: B53A-0978    [Abstracts]
TI: Embedded Networked Sensing in Support of Managing Irrigation with Reclaimed Wastewater
AU: * Park, Y
EM: yp32@ucla.edu
AF: Department of Civil & Environmental Engineering, UCLA, 5731/5732 Boelter Hall Box 159310, Los Angeles, CA 90095 United States
AU: Kim, J
EM: hispeace@ucla.edu
AF: Department of Civil & Environmental Engineering, UCLA, 5731/5732 Boelter Hall Box 159310, Los Angeles, CA 90095 United States
AU: Harmon, T C
EM: tharmon@ucmerced.edu
AF: School of Engineering, University of California, Merced, P.O. Box 2039, Merced, CA 95344 United States
AB: An issue associated with agricultural irrigation using reclaimed wastewater is the potential threat to underlying groundwater quality. A prime example is nitrate, which serves as a fertilizing agent but has the potential to leach into groundwater. In order to balance water reuse and groundwater protection, intelligent irrigation management and monitoring systems are required for such water reuse systems. In this work, a nonlinear programming-based control algorithm is proposed to optimize irrigation scheduling subject to contaminant transport constraints. In support of the algorithmic developments, a networked sensor array is being designed for deployment at an agricultural research plot. This array will supply real-time field information about water infiltration and distribution, nitrate propagation, and heat transport, to the irrigation scheduling algorithm. The control scheme (measurement, decision, and action) will be continuously updated using on-line feedback from sensors. The simulator on which the management algorithm depends is a one-dimensional form of the Richards equation coupled to energy and solute transport mass balances. The simulator is used to (1) estimate key soil hydraulic and transport parameters in near real time, and (2) predict nitrate concentrations with respect to time and depth as input to the management algorithm. The quantity and timing of irrigation is determined based on an optimization algorithm which maximizes the reclaimed water usage while preventing nitrate propagation below a predetermined depth. Additional constraints are associated with plant water needs, and avoiding runoff and spray drift from the experimental plot. Results from a parameter sensitivity analysis are presented and preliminary management schemes are demonstrated for an on-going field experiment.
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting