msu-ceco/aec_v1 · Datasets at Hugging Face

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These pressures can be several times the normal operating pressure and result in broken pipes and severe damage to the irrigation system.
The high pressures resulting from the water hammer can not be effectively relieved by a pressure relief valve due to the high velocity of the pressure wave.
The best prevention of water hammer is the installation of valves that can not be rapidly closed, and the selection of air vents with the appropriate orifice which do not release air too rapidly.
Pipelines are usually designed to maintain velocities below 5 fps in order to avoid high surge pressures from occurring.
Surge pressures may be calculated by the following :
P = {0.028 Eq.
12 where, Q = flow rate D = pipe I.D.
P = surge pressure L = length of pipeline T = time to close valve
For an 8-inch Class 160 PVC pipeline that is 1,500 feet long and has a flow rate of 750 gpm, compare the potential surge pressure caused when a butterfly valve is closed in 10 seconds to a gate valve that requires 30 seconds to close.
From Table 1, diameter of 8 inch pipe is 7.961 inches
Surge Pressure = 0.028 X / = 49.7 psi
Surge Pressure = 0.028 X / = 16.57 psi
Head Losses in Lateral Lines
From the above example, it is clear that increasing the closing time for valves can reduce the surge pressure.
Microsprinkler field installations typically have 10-20 gph emitters.
Emitters are normally attached to stake assemblies that raise the emitter 8-10 inches above the ground, and the stake assemblies usually have 2-3 ft lengths of 4-mm spaghetti tubing.
The spaghetti tubing is connected to the polyethylene lateral tubing with a barbed or threaded connector.
The amount of head loss in the barbed connector can be significant, depending on the flow rate of the emitter and the inside diameter of the connector.
The pressure loss in a 0.175 inch barb X barb connector is shown in Figure 3.
At 15 gph, about 1 psi is lost in the barbed connection alone.
Figure 3.
Pressure loss versus flow rate for 0.175 inch barb X barb connector.
In addition to the lateral tubing connection, there will be pressure losses in the spaghetti tubing.
Figure 4 shows the pressure required in the lateral line to maintain 20 psi at the emitter for various emitter orifices and spaghetti tubing lengths.
Note that with the red base emitters , an additional 25-30% pressure is required in the lateral tubing to maintain 20 psi at the emitter.
It is important to realize the hydraulic limits of irrigation lateral lines to efficiently deliver water.
Oftentimes when resetting trees, 2 or more trees are planted for each tree taken out.
If a microsprinkler is installed for each of the reset trees, the effects of increased emitters on the system uniformity and system performance can be tremendous.
Not only will friction losses increase and average emitter discharge decrease, but system uniformity and efficiency will decrease.
Figure 5 shows the maximum length of lateral tubing that is possible while maintaining + 5% flow variation on level ground with a 20 psi average pressure.
The discharge gradient is calculated by dividing the emitter flow rate by the emitter spacing.
Figure 4.
Lateral line pressure required to maintain 20 psi at emitter for various emitter orifice sizes and spaghetti tube lengths.
Figure 5.
Lateral length allowable to achieve +/5% flow variation for level ground with 22 psi inlet pressure for 1/2-, 3/4-, and 1-inch lateral tubing.
The maximum number of microsprinkler emitters and maximum lateral lengths for 0.75, and 1-inch lateral tubing is given in Table 5 and Table 6.
Similar information for drippers with 0.5, 0.75, and 1-inch lateral tubing is given in Table 7, Table 8, and Table 9.
All calculations are based on +5% allowable flow variation on level ground.
By knowing the emitter discharge rate, spacing, and tubing diameter, the maximum number of emitters and the maximum lateral length can be determined.
Determine the maximum allowable run length for 0.75inch lateral tubing with 10 gph emitters spaced at 12-ft intervals.
Discharge gradient = 10 gph / 12 ft = 0.83 gph/ft
From Figure 5, maximum run length corresponding to 0.83 gph/ft gradient is about 380 ft.
Determine the maximum allowable run length for 0.75inch lateral tubing with 12 gph emitters spaced at 10-ft intervals.
For 12 gph and 10-ft spacing, :
Maximum number of emitters: 31
Maximum lateral length: 313 ft
Alternatively, Figure 5 can be used to compute the maximum lateral length for +/-5% flow variations.
Discharge gradient = 12 gph/10 ft = 1.2 gph/ft
Corresponding value for 1.2 gph/ft from Figure 5 is 300 ft.
Using Tables 7 to 9, determine the maximum allowable run length for 0.75-inch lateral tubing with 1.0 gph drip emitters spaced at 30-inch intervals.
From Table 8 for 1.0 gph at 30-inch spacing,
Maximum number of emitters: 227
Maximum lateral length: 568 ft
The last few irrigations of the season require some of the most important water management decisions of the year.
An extra irrigation may mean wasting 1 to 3 inches of water and 2 to 5 gallons of diesel fuel per acre.
Furrow irrigators may want to decide sooner due to the typical higher application amounts with flood, while pivot irrigators can delay the decision and take advantage of any rainfall that may occur.
The final criteria is that the impeller operate at near maximum efficiency.
Irrigated fields have some level of elevation change, but since the design is based on the worst case scenario most of the field will receive greater pressure and flow rate than needed.
Enter VFDs.
With pumping costs ranging from $6-15/acre-inch this year, any opportunity to save money by cutting back irrigation as early as possible sounds like a good strategy.
Correctly timing the last few irrigations of the season offers an excellent opportunity to save some water and money.
Daily information from the Dudley Ridge CIMIS weather station was used to estimate water requirements for mature walnuts, as well as irrigation timing and quantity.
Implementing CIMIS at the farm level: a grower's experience in walnuts
The California Irrigation Management Information System originated in 1982.
Its purposes were to provide estimates of crop water requirements as influenced by real-time weather conditions and to ensure reasonable use of limited water supplies for farming.
This study documents the effects of managing on-farm irrigation practices, with and without using CIMIS information, in a Kings County walnut orchard.
In this example, increased water use, increased production, and increased profits were experienced as a result of implementing CIMIS information.
It has been charged that existing irrigation practices on agricultural lands in California use limited water supplies inefficiently.
In partial response, the California Irrigation Management Information System was initiated in 1982 to ensure reasonable use of limited water supplies on agricultural croplands.
Objectives of the CIMIS program have been to provide estimates of crop water requirements based upon real-time weather conditions and to promote adoption of CIMIS information into the irrigation scheduling practices of growers in California.
CIMIS consists of a network of about 65 automated weather stations located throughout the state.
Under the management of the California Department of Wa-
ter Resources' Office of Water Conservation, hourly weather data is logged from each station onto a mainframe computer in Sacramento.
The public can obtain this information by calling the Department of Water Resources at 445-8259, by contacting public water agencies, or by referring to various publications.
Installation of the ribs restricted water flow to 80%-85% of full capacity, and water flow for the 2020 growing season was reduced to approximately 1,200 cubic feet per second.
How to Close an Abandoned Well Steve Higgins and Sarah Wightman, Biosystems and Agricultural Engineering
A bandoned wells are often the only structures remaining after an old house or barn has been removed.
If left unmanaged in agricultural areas, these abandoned wells can pose a serious threat to livestock and human safety because of the large surface openings they often have.
Abandoned wells can also affect water quality, water as the shaft that forms bearing zone the well creates a conduit directly into groundwater resources.
If wells are not closed properly, pollutants present on the surface, including sediment, manure, and pesticides, can be transported through stormwater runoffin the groundwater through that conduit.
Water quality is also negatively impacted when livestock fall into these openings or the openings are used as a way to dispose of dead livestock.
Landowners can be held liable for groundwater contamination originating from a polluted well, just as they can for accidents caused by an abandoned well.
The goal of this publication is to provide information on the proper way to close an unused well, which will help prevent accidents and protect drinking water.
There are several types of wells that can be found on agricultural properties, including drilled wells, wells with multiple casings, bored and hand-dug wells, driven wells, and flowing artesian wells.
Figure 1.
This properly functioning well could become a hazard if abandoned.
To locate an abandoned well, search old photographs, fire insurance plan drawings, health department records, and water utility records.
Also, ask neighbors and former property owners for information.
Look for well casings, waterlines, pressure tanks, pumps, and electrical components such as wiring in the yard or basement or near old windmills or pump houses.
Metal detectors can help locate metal casings.
Figure 2.
This abandoned well has an open side, which makes it possible for pollutants to enter the aquifer unabated.
Figure 3.
This abandoned well is located in an agricultural area that is void of vegetation that could filter pollutants from stormwater runoff and reduce the amount of pollution entering groundwater resources.
Landowners in Kentucky are responsible for decommissioning abandoned wells within 30 days of deeming them unusable or unneeded.
Abandoned wells have clear guidelines for closure under the law , and all of the work needs to be accomplished by a Kentucky certified water well driller.
Figure 4.
This well's large opening could be hazardous for nearby livestock.
Before closing a well, measurements of the well depth, diameter, and its depth to static water level need to be taken and recorded in the Uniform Kentucky Well Maintenance and Plugging Record.
All obstructions must be removed from the well before closure.

These pressures can be several times the normal operating pressure and result in broken pipes and severe damage to the irrigation system.

The high pressures resulting from the water hammer can not be effectively relieved by a pressure relief valve due to the high velocity of the pressure wave.

The best prevention of water hammer is the installation of valves that can not be rapidly closed, and the selection of air vents with the appropriate orifice which do not release air too rapidly.

Pipelines are usually designed to maintain velocities below 5 fps in order to avoid high surge pressures from occurring.

Surge pressures may be calculated by the following :

P = {0.028 Eq.

12 where, Q = flow rate D = pipe I.D.

P = surge pressure L = length of pipeline T = time to close valve

For an 8-inch Class 160 PVC pipeline that is 1,500 feet long and has a flow rate of 750 gpm, compare the potential surge pressure caused when a butterfly valve is closed in 10 seconds to a gate valve that requires 30 seconds to close.

From Table 1, diameter of 8 inch pipe is 7.961 inches

Surge Pressure = 0.028 X / = 49.7 psi

Surge Pressure = 0.028 X / = 16.57 psi

Head Losses in Lateral Lines

From the above example, it is clear that increasing the closing time for valves can reduce the surge pressure.

Microsprinkler field installations typically have 10-20 gph emitters.

Emitters are normally attached to stake assemblies that raise the emitter 8-10 inches above the ground, and the stake assemblies usually have 2-3 ft lengths of 4-mm spaghetti tubing.

The spaghetti tubing is connected to the polyethylene lateral tubing with a barbed or threaded connector.

The amount of head loss in the barbed connector can be significant, depending on the flow rate of the emitter and the inside diameter of the connector.

The pressure loss in a 0.175 inch barb X barb connector is shown in Figure 3.

At 15 gph, about 1 psi is lost in the barbed connection alone.

Figure 3.

Pressure loss versus flow rate for 0.175 inch barb X barb connector.

In addition to the lateral tubing connection, there will be pressure losses in the spaghetti tubing.

Figure 4 shows the pressure required in the lateral line to maintain 20 psi at the emitter for various emitter orifices and spaghetti tubing lengths.

Note that with the red base emitters , an additional 25-30% pressure is required in the lateral tubing to maintain 20 psi at the emitter.

It is important to realize the hydraulic limits of irrigation lateral lines to efficiently deliver water.

Oftentimes when resetting trees, 2 or more trees are planted for each tree taken out.

If a microsprinkler is installed for each of the reset trees, the effects of increased emitters on the system uniformity and system performance can be tremendous.

Not only will friction losses increase and average emitter discharge decrease, but system uniformity and efficiency will decrease.

Figure 5 shows the maximum length of lateral tubing that is possible while maintaining + 5% flow variation on level ground with a 20 psi average pressure.

The discharge gradient is calculated by dividing the emitter flow rate by the emitter spacing.

Figure 4.

Lateral line pressure required to maintain 20 psi at emitter for various emitter orifice sizes and spaghetti tube lengths.

Figure 5.

Lateral length allowable to achieve +/5% flow variation for level ground with 22 psi inlet pressure for 1/2-, 3/4-, and 1-inch lateral tubing.

The maximum number of microsprinkler emitters and maximum lateral lengths for 0.75, and 1-inch lateral tubing is given in Table 5 and Table 6.

Similar information for drippers with 0.5, 0.75, and 1-inch lateral tubing is given in Table 7, Table 8, and Table 9.

All calculations are based on +5% allowable flow variation on level ground.

By knowing the emitter discharge rate, spacing, and tubing diameter, the maximum number of emitters and the maximum lateral length can be determined.

Determine the maximum allowable run length for 0.75inch lateral tubing with 10 gph emitters spaced at 12-ft intervals.

Discharge gradient = 10 gph / 12 ft = 0.83 gph/ft

From Figure 5, maximum run length corresponding to 0.83 gph/ft gradient is about 380 ft.

Determine the maximum allowable run length for 0.75inch lateral tubing with 12 gph emitters spaced at 10-ft intervals.

For 12 gph and 10-ft spacing, :

Maximum number of emitters: 31

Maximum lateral length: 313 ft

Alternatively, Figure 5 can be used to compute the maximum lateral length for +/-5% flow variations.

Discharge gradient = 12 gph/10 ft = 1.2 gph/ft

Corresponding value for 1.2 gph/ft from Figure 5 is 300 ft.

Using Tables 7 to 9, determine the maximum allowable run length for 0.75-inch lateral tubing with 1.0 gph drip emitters spaced at 30-inch intervals.

From Table 8 for 1.0 gph at 30-inch spacing,

Maximum number of emitters: 227

Maximum lateral length: 568 ft

The last few irrigations of the season require some of the most important water management decisions of the year.

An extra irrigation may mean wasting 1 to 3 inches of water and 2 to 5 gallons of diesel fuel per acre.

Furrow irrigators may want to decide sooner due to the typical higher application amounts with flood, while pivot irrigators can delay the decision and take advantage of any rainfall that may occur.

The final criteria is that the impeller operate at near maximum efficiency.

Irrigated fields have some level of elevation change, but since the design is based on the worst case scenario most of the field will receive greater pressure and flow rate than needed.

Enter VFDs.

With pumping costs ranging from $6-15/acre-inch this year, any opportunity to save money by cutting back irrigation as early as possible sounds like a good strategy.

Correctly timing the last few irrigations of the season offers an excellent opportunity to save some water and money.

Daily information from the Dudley Ridge CIMIS weather station was used to estimate water requirements for mature walnuts, as well as irrigation timing and quantity.

Implementing CIMIS at the farm level: a grower's experience in walnuts

The California Irrigation Management Information System originated in 1982.

Its purposes were to provide estimates of crop water requirements as influenced by real-time weather conditions and to ensure reasonable use of limited water supplies for farming.

This study documents the effects of managing on-farm irrigation practices, with and without using CIMIS information, in a Kings County walnut orchard.

In this example, increased water use, increased production, and increased profits were experienced as a result of implementing CIMIS information.

It has been charged that existing irrigation practices on agricultural lands in California use limited water supplies inefficiently.

In partial response, the California Irrigation Management Information System was initiated in 1982 to ensure reasonable use of limited water supplies on agricultural croplands.

Objectives of the CIMIS program have been to provide estimates of crop water requirements based upon real-time weather conditions and to promote adoption of CIMIS information into the irrigation scheduling practices of growers in California.

CIMIS consists of a network of about 65 automated weather stations located throughout the state.

Under the management of the California Department of Wa-

ter Resources' Office of Water Conservation, hourly weather data is logged from each station onto a mainframe computer in Sacramento.

The public can obtain this information by calling the Department of Water Resources at 445-8259, by contacting public water agencies, or by referring to various publications.

Installation of the ribs restricted water flow to 80%-85% of full capacity, and water flow for the 2020 growing season was reduced to approximately 1,200 cubic feet per second.

How to Close an Abandoned Well Steve Higgins and Sarah Wightman, Biosystems and Agricultural Engineering

A bandoned wells are often the only structures remaining after an old house or barn has been removed.

If left unmanaged in agricultural areas, these abandoned wells can pose a serious threat to livestock and human safety because of the large surface openings they often have.

Abandoned wells can also affect water quality, water as the shaft that forms bearing zone the well creates a conduit directly into groundwater resources.

If wells are not closed properly, pollutants present on the surface, including sediment, manure, and pesticides, can be transported through stormwater runoffin the groundwater through that conduit.

Water quality is also negatively impacted when livestock fall into these openings or the openings are used as a way to dispose of dead livestock.

Landowners can be held liable for groundwater contamination originating from a polluted well, just as they can for accidents caused by an abandoned well.

The goal of this publication is to provide information on the proper way to close an unused well, which will help prevent accidents and protect drinking water.

There are several types of wells that can be found on agricultural properties, including drilled wells, wells with multiple casings, bored and hand-dug wells, driven wells, and flowing artesian wells.

Figure 1.

This properly functioning well could become a hazard if abandoned.

To locate an abandoned well, search old photographs, fire insurance plan drawings, health department records, and water utility records.

Also, ask neighbors and former property owners for information.

Look for well casings, waterlines, pressure tanks, pumps, and electrical components such as wiring in the yard or basement or near old windmills or pump houses.

Metal detectors can help locate metal casings.

Figure 2.

This abandoned well has an open side, which makes it possible for pollutants to enter the aquifer unabated.

Figure 3.

This abandoned well is located in an agricultural area that is void of vegetation that could filter pollutants from stormwater runoff and reduce the amount of pollution entering groundwater resources.

Landowners in Kentucky are responsible for decommissioning abandoned wells within 30 days of deeming them unusable or unneeded.

Abandoned wells have clear guidelines for closure under the law , and all of the work needs to be accomplished by a Kentucky certified water well driller.

Figure 4.

This well's large opening could be hazardous for nearby livestock.

Before closing a well, measurements of the well depth, diameter, and its depth to static water level need to be taken and recorded in the Uniform Kentucky Well Maintenance and Plugging Record.

All obstructions must be removed from the well before closure.