Design Data

Irrigation Water Consumption

Efficiency Model

Problem: What is the best way to water an acre of land for
– even distribution over the entire area +/- X%
– minimum water consumption
– maximum plant product growth/yield
– maximum net profit / return on investment

Controlling Variables
1. What percentage of water carries over I.e. is lost in the wind?
2. What percentage evaporates before sinking into ground?
3. How does relative humidity affect carryover and evaporation?
4. Consider watering more on cloudy days to reduce evaporation
5. Consider watering less on windy days to reduce evaporation

Solution Set
First order problem – even distribution over surface large area – nozzle design, operation and arrangement
How control of pressure and flow impacts coverage including nozzle selection and spray droplet size distribution
Second order problem – even saturation into soil considering solar position, relative humidity, and wind velocity i.e. minimize carryover and evaporation rates
Third order problem – optimum feed times and feed rates to maximize plant product yields – sunlight level, ambient temperatures, and continuous vs intermittent feeding
Basic Calculations
1. Calculate delivery of fixed amount of water to an acre.
2. Equivalent to 1/2/3/4/5/6/7/8/9/10 feet per year gross
3. Even distribution per day 1/2/3/4/6/12/24 times per day
4. Determine flow rate 1/2/5/10/20/50/100 gpm and flow duration 1/2/3/6/10/20/30/60 minutes

Configuration Considerations

1. Fixed pressure supply
2. Fixed speed pump supply
3. Variable speed pump supply