Non Linear Economic Models for Crop Production
Most economic models for crop production rely on the traditional linear programming approach, in spite of the fact that the objective function is almost always non linear. This paper briefly...
Crop Production Models in Water Management
A weather generating model called WMAKER is introduced. The model generates daily climatic data based on the mean monthly values of temperature, precipitation, number of rainy days and...
Choices Between Micro and Mainframe Computers
The explosion of microcomputers (PCs) has shifted a great amount of engineering computing from mainframes to micros. It has also shifted a lot of programming from FORTRAN to BASIC. This...
The Use of Spread Sheets in Water Resources Planning
With the advent of 'spread sheets' in the microcomputer explosion, a tool is available for the first time to greatly simplify many engineering procedures. This...
Sprinkler Erosion Model
The Soil Conservation Service has developed a model to evaluate the effect of various sprinkler irrigation systems with associated agronomic practices. Many researchers have dealt with...
Delivery System Management Via Dynamic Programming
Management of irrigation water delivery systems may involve allocating limited water supplies over both time and space under uncertain future demands. The physical delivery systems are...
Interactive Surface Irrigation Design and Evaluation Software
This paper outlines the features and capabilities of a comprehensive personal computer software system for use by irrigation engineers in design and evaluation of continuous and surge...
A Simulation Procedure for On-Farm Irrigation Systems Planning
A simulation modeling package has been developed for modeling on-farm irrigation water supply and application systems. The modeling package can consider up to 6 different application systems...
Bowen Ratio and Penman: Australian-California Tests
Results are presented of evapotranspiration (ET) studies conducted in Davis, California and at two locations in Australia. Good agreements were obtained in early comparisons of Bowen Ratio...
Calibration of an Evapotranspiration Model Using Eddy Correlation Methods
An evapotranspiration (ET) prediction model was developed by calibrating the H. L. Penman equation for an alfalfa reference crop in the southwestern Oklahoma region. Evaporative flux for...
The Relationship of Benefits to System Size for Irrigation Projects
This paper presents a generalized linear programming (LP) and farm budget model for optimization of on-farm irrigation benefits resulting from variations in irrigation project size. The...
Considerations for Sizing Water Delivery Systems
The purpose of a water delivery system is to deliver irrigation water to a farm and its design should be based on meeting the requirements of farm water use. The rate, duration and frequency...
Daily Diversion Forecasting for a Large Irrigation Project
A procedure has been developed and tested to forecast demand-type large irrigation diversions on a daily basis. The model is based on hydrologic concepts as well as irrigation scheduling...
Meixner Functions Model Crop Yield vs. Applied Water
Most crop production functions are reported as linear functions even though everyone knows they are not. The few examples of non linear crop production functions that exist in the literature...
Infiltration as a Dependent Variable in Modeling Furrow Irrigation
Most surface irrigation models assume that infiltration is independent of surface flow hydraulics. However, wetted perimeter has been shown to significantly affect infiltration in furrows....
Optimum Irrigation Under Saline Conditions
A dynamic production function for cotton is estimated. Optimal irrigation volumes, timing, and qualities are calculated using dynamic programming. Optimal water quantities are sensitive...
Steady State Fluid Transport Model for Plants
Knowledge of water potentials throughout the xylem and phloem elements as well as in individual cells is fundamental for understanding effects of water and temperature stress on transport...
Satellite Remote Sensing for Regional Crop Inventories
LANDSAT 4 and 5 Satellite spectral images of the Columbia Basin were obtained during the 1984, 1985 and 1986 growing seasons by Cropix, Inc. of Hermiston, Oregon. A field classification...
Estimating Number and Duration of On-Times for Surge Irrigation
Research shows surge flow can achieve efficient and uniform irrigation on some soils. However, most available information focuses on computerized analysis and modeling for research purposes....
Runoff Model for Watersheds of Nonhomogeneous Characteristics
A watershed of any configuration, topography, and spatial distribution of cover, soil and channel characteristics is described as a plannar grid. Time-varying precipitation is applied...
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