Week 2 Irrigation Notes

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By: Doc McDowell
Created: 2011-10-09
Size: 24 flashcards
Views: 3

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Define Precipitation Rate

the speed at which a sprinkler or an irrigation system applies water. Measured in the U.S. as Inches Per Hour (in./hr)

What counts as a Low irrigation rate?

0.5 in/hr and below

What counts as a Medium irrigation rate?

0.5 to 1.0 in.hr

What Counts as a high irrigation rate?

1.0 in./hr and above

What are two types of sprinklers with high PR?

1) Fixed Spray
2) Bubblers

What are two spinklers with low to modereate PR?

1) Gear Rotars
2) Impact Rotars

What is an advantage of using a high percipitation rate Sprinkler?

Idealfor level, coarse textured soils with high infiltration rates and little hazard of erosion

What is an advantage of using a medium percipitation rate sprinkler?

Ideal for level, coarse textured soil with high infiltration rates with little hazard of resion (like High PR sprinklers) BUT can be run longer

What is an advantage of using a low PR sprinkler?

Ideal for a wide variety of slopes and soil textures without excessive runoff or soil erosion

How do you compare a sprinkler PR with a system PR?

A sprinkler PR deals with a single sprinkler head output while a system PR refers to precipitation rates in an overall irrigation system

When choosing a sprinkler head, what factors must be assessed about the landscape?

1) Soil Texture
2)Maximum percipitation rates per USDA standards
3) Slope

It is a misconception that sprinkler systems with low PR take longer to irrigate a landscape. Why is this false?

Because more heads can be operated at one time thus increasing the PR rates for the time alloted

The total run time is limited by the __________ available from the water source, NOT the precipitation rate of the sprinkler system

Gallons per Minute (GPM)

What is the sprinkler spacing method formula?

Pr = 96.25 x GPM (for a 360 degree head) / Head Spacing * Row spacing

Where
Head Spacing is the distance in feet between heads in the same row
Row Spacing is the distance in feet between the row of sprinklers

What is the sprinkler spacing formula for spray arcs under 360 degrees?

Pr = 34650 x GPM / Degree of arc * Head Spacing * Row Spacing

IF a full circle head has a coverage diameter of 40 feet what is it's radius?

20 ft (exactly half)

What is a half circle arc equal to in degrees?

180

Give an ecample of the modified sprinkler Spacing method

Pr = 34650 x GPM / Arc * Head spacing * Row spacing

ex.
34650 x 2.5 / 180 * 20 * 20
= 86625 / 72000
=1.20 in./hr

How does one perform the Total Area Method Formula?

pr = 96.25 * Total GPM / Total Area

A Sprinkler flow increase means a(n) ____________ with precipitation rates

Increase

Decreasing head and row spacing _________ precipitation rate

Increases

How is radius adjustment accomplished?

1) An internal change in pressure and flow (GPM)
2) External Disruption of spray with no change in flow but a modification in radius of throw

What is distribution uniformity?

The measurement of how evenly the water is applied to the area

About this deck

By: Doc McDowell
Created: 2011-10-09
Size: 24 flashcards
Views: 3

About StudyBlue

“I have used this website for three exams, and I see a huge difference in my test results.”
Naj