Editor’s Note

In this issue of the Journal, you will find twelve papers and two technical notes, along with a discussion and closure. Ten of the papers and one of the technical notes deal with various aspects of irrigation management. The first two papers, entitled “Model for the Simulation of Water Flows in Irrigation Districts. I: Description” and “II. Application,” by Lecina and Playán, deal with a model used to predict water use in irrigation districts in Spain. The first paper describes the model, and the second paper deals with calibrating the model, as well as simulation and comparison with actual seasonal water demand.

The third and fourth papers—entitled “Performance-Based Optimization of Land and Water Resources within Irrigation Schemes. I: Method” and “II. Application”—are companion papers by Smout, Gorantiwar, and Vairavamoorthy that discuss the area and water allocation model (AWAM), which is a simulation–optimization model to allocate land and water resources for different crops. The third paper discusses the framework of the model, and the fourth paper discusses the model’s application to an irrigation district in India. The fifth paper, entitled “Productivity and Equity of Different Irrigation Schedules under Limited Water Supply,” is also by Smout and Gorantiwar and discusses another application of the model under limited water supply.

The sixth paper—entitled “Tuning of Robust Distant Downstream PI Controllers for an Irrigation Canal Pool. I: Theory,” by Litrico and Fromion, and the seventh paper, entitled “Tuning of Robust Distant Downstream PI Controllers for an Irrigation Canal Pool. II. Implementation Issues,” by Litrico, Fromion and Baume—are also companion papers from Cemagref in France. The two papers discuss the theory and application of a new method to tune robust distant downstream proportional integral (PI) controllers for an irrigation canal pool.

The eighth paper, “Efficient Solution of the Coupled One-Dimensional Surface—Two-Dimensional Subsurface Flow during Furrow Irrigation Advance,” by Wöhling et al. deals with coupling an analytical zero-inertia 1D surface flow model with the 2D subsurface water transport model HYDRUS-2 to predict hydrodynamic flow in furrow irrigation. The ninth paper, which is also a modeling paper, is entitled “Regional Salinity Modeling for Conjunctive Water Use Planning in Kheri Command.” This paper—by Kaledhonkar and Keshari—discusses the calibration and validation of a one-dimensional water solute transport model UNSATCHEM and its application in the Kheri Command in India to predict regional root-zone salinity. From the model, guidelines for sustainable conjunctive water use planning can be developed that use saline groundwater.

The tenth paper, “Economic Analysis of an Irrigation System for Liquid Manure Application,” by Ancev and Stoecker, presents methodology to select the least-cost irrigation system for applying liquid animal manure from lagoons. The methodology was applied to three farrow-to-finish swine farms.

The eleventh paper, “Flow Depletion of Semipervious Streams due to Unsteady Pumping Discharge,” by Singh, develops analytical expressions for rate and volume of flow depletion of semipervious streams due to unsteady pumping rates. The twelfth paper, “Storm-Water Predictions by Dimensionless Unit Hydrograph,” by Guo, presents a theoretical deviation of the dimensionless unit hydrograph by using the kinematic wave approach.

The first technical note, “Sensitivity Analysis of Soil Hydraulic Properties on Subsurface Water Flow in Furrows,” is by Rocha et al. and discusses the results of an extensive sensitivity analysis of various soil hydraulic properties that are important to subsurface flow in furrow irrigation. The second technical note, entitled “VOF Model for Simulation of a Free Overfall in Trapezoidal Channels,” by Ramamurthy et al., presents the development of a volume of fluid (VOF) turbulence model to determine pressure head distributions, velocity distributions, and water surface profiles for the face overall in a trapezoidal-shaped open channel. The proposed model was validated by using experimental data.