Eduardo Bautista

Real-time implementation of model predictive control on Maricopa-Stanfield Irrigation and Drainage District's WM Canal.

Water resources are limited in many agricultural areas. One method to improve the effective use of water is to improve delivery service from irrigation canals. This can be done by applying automatic control methods that control the gates in an irrigation canal. The model predictive control (MPC) is one such advanced control method. In this article, the MPC is used to deliver irrigation water to the WM Canal at the Maricopa-Stanfield Irrigation and Drainage District. The tests show that the water is efficiently delivered to the users and water level deviations at all locations are small. The control is compared to the results from an advanced Linear Quadratic Regulator control method, also tested on the actual canal.

Estimation of Soil and Crop Hydraulic Properties

Some two dozen methods for estimating infiltration and roughness parameters from field measurements of test irrigations are reviewed in this paper. They differ in their assumptions, ease of analysis, quantity of field data required, and accuracy. They are divided into two broad categories, depending upon the basic approach to determine infiltration. One features direct application of mass conservation, expressed in terms of the infiltration parameters and then inverted in some way in order to extract those parameters. The other involves repeated simulation with a sequence of values of the infiltration parameters, coupled to some kind of search procedure—an optimization—to minimize differences between simulation and measurement. A new one-point technique is proposed, along with suggestions for extending existing methods.

The Management Improvement Program (MIP): A Process For Improving the Performance of Irrigated Agriculture

Enhanced long-term management ofnatural resources, farmer profitability, and overallsocial well-being are essential to sustainableirrigated agriculture. Because these objectives oftenseem to conflict, all agriculturalstakeholders – farmers, irrigation districts, supportand regulatory government agencies, and otherinterested parties – need to interact proactively toidentify and address common needs. To this end, theManagement Improvement Program (MIP) was tested in theMaricopa-Stanfield Irrigation and Drainage District(MSIDD) area in central Arizona, USA, as a managedchange process to improve the performance of anirrigated agricultural system. The three-phased MIPprocess consists of (1) analysis of the currentperformance of the agricultural system, on- andoff-farm, to gain a common, shared understanding; (2) developmentby the stakeholders of plans foralternatives to address identified opportunities forimprovement; and (3) collaborative implementation ofthe plans. This paper describes the MIP process andits methodological origins, provides an account of theinitial application of the MIP process to an irrigatedagricultural system in the United States, andhighlights some important outcomes of the MIPapplication.

Field Properties in Surface Irrigation Management and Design

Field properties—topography, hydraulic resistance, and infiltration—play an important role in the performance of surface irrigation systems, and appropriate characterizations of these are required as data input to simulation or design software. The EWRI/ASCE Task Committee on Soil and Crop Hydraulic Properties has been charged with preparing a guide for practitioners faced with such data entry. The result is this special section of the Journal of Irrigation and Drainage Engineering in which this paper is the first in the series presented. It describes the characteristics of these field properties and notes a series of caveats to be considered when dealing with them in the course of analyses or designs of surface irrigation systems.

Toward physically based estimation of surface irrigation infiltration.

Irrigation practitioners use empirical infiltration equations. Theoretical infiltration equations are currently not capable of capturing surface irrigation infiltration behavior, particularly during initial wetting. For a coarse textured soil, an example is shown where the Green-Ampt equation can be adjusted to match field “average” infiltration conditions by altering the soil’s physical properties. For finer textured soils, a time offset is proposed for adjusting the Green-Ampt equation to account for cracking and soil consolidation upon wetting. This results in a nonzero infiltration amount at time 0, a phenomenon commonly observed for infiltration of cracking soils. Applying this concept to the Philip equation (same as Modified Kostiakov equation with a=1/2 ) suggests the addition of an offset parameter. A modification to the two-point method is presented for this equation with the aim to better fit mathematical parameter functions to infiltration data.

Diagnostic Analysis of the Maricopa-Stanfield Irrigation and Drainage District Area

Diagnostic Analysis (DA) is a methodologyfor assessing and understanding the performance of anagricultural system. This analysis is thefirst step in a large system change process, known asthe Management Improvement Program (MIP), whoseobjective is to improve the performance of the agricultural system.A group of Federal andstate of Arizona agencies agreed to apply the MIPmethodology in a western U.S. setting. The purpose of theapplication was to test the applicability of the MIPapproach and to refine themethodology. This paper describes how the DAmethodology was applied in the Maricopa-StanfieldIrrigation and Drainage District (MSIDD) area incentral Arizona, USA, and summarizes the lessonsderived from that experience. Specific findings ofthe DA study and the response of MSIDD areaagriculture to those findings are discussed inseparate articles.

Simulation of Unsteady Flow and Soil Erosion in Irrigation Furrows

AbstractThis study developed a one-dimensional numerical model for the simulation of unsteady flow and the resultant soil erosion in irrigation furrows. The model solves a modified version of the Saint-Venant equations that consider the loss of mass and momentum attributable to infiltration and sediment transport. The transport rate of fine sediment was predicted with a modified Laursen formula that treats the tractive shear stress as a function of both Reynolds number and the particle size. The modified Laursen formula was verified by using the erosion data measured in the field and in a laboratory flume. The model accurately predicted flow advance times and outflow hydrographs in comparison with data measured in irrigation furrows at Kimberly, Idaho. Sediment discharge predictions were less accurate.

Optimal and postirrigation volume balance infiltration parameter estimates for basin irrigation.

Engineering analysis of surface irrigation systems is predicated on reasonably accurate estimates of a field’s infiltration properties. Optimal estimation methods pose multiple volume balance equations at various stages of an irrigation event and are assumed to produce the most accurate results among volume balance based procedures. They have the disadvantage of requiring surface volume determinations, which may be difficult to obtain in practice under many field conditions. This study contrasts infiltration solutions from optimal and a simpler postirrigation volume balance method and examines the implications of those solutions on the performance of management strategies with zero-slope and low-gradient basins. With those types of systems, there is little benefit in using optimization over postirrigation volume balance due to the nonuniqueness of solutions and uncertainties of inputs required by the estimation procedures. In addition, system hydraulic characteristics mitigate the insensitivity of the dis...

Approximate Furrow Infiltration Model for Time-Variable Ponding Depth

AbstractA methodology is proposed for estimating furrow infiltration under time-variable ponding depth. The methodology approximates the solution to the two-dimensional Richards equation, and is a modification of a procedure that was originally proposed for computing infiltration under constant ponding depth. Two computational approaches were developed and tested using several combinations of soil hydraulic properties, furrow geometry, and flow depth variations. Both methods yielded solutions of reasonable and similar accuracy relative to numerical solutions of the two-dimensional Richards equation. The analysis also showed that the accuracy of the approximate model varies mostly as a function of soil hydraulic properties. The accuracy of the approximate solution can be improved with calibration. Two calibration methods were examined, one assuming that the calibration parameter varies with depth, and the other assuming a constant value. The analysis showed that latter approach, in combination with one of ...

Nonuniform and Unsteady Solute Transport in Furrow Irrigation. II: Description of Field Experiments and Calibration of Infiltration and Roughness Coefficients

Field tests were conducted to obtain irrigation evaluation and solute transport data. The data were used to calibrate and validate an advection-dispersion model for furrow irrigation. The empirical infiltration equation and roughness parameters were estimated from the evaluation data. The inflow rate was measured with a volumetric meter and a flume and resulted in different average inflow rates. Hydraulic simulation results proved nearly as accurate with infiltration function estimates derived from the meter or flume data despite the difference in measured flow rate. Hence, the calibrated infiltration functions provide limited clues about possible problems with the inflow data. The choice of the infiltration equation used to fit the data (Branch versus modified Kostiakov) produced greater differences in the hydraulic modeling results. The timing and spread of the solute concentration pulses were well predicted independently of the inflow data and infiltration equation used to fit the data. However, differ...