B. Irrigation and Drainage Engineering Flashcards
The moisture content of the soil when the gravitational water has been removed.
a. Available water
b. Field capacity
c. Permanent wilting point
d. Readily available moisture
b. Field capacity
Subsurface drain system wherein laterals join the submain on both sides alternately.
a. Gridiron
b. Herringbone
c. Parallel drain system
d. Double main system
b. Herringbone
Darcy’s law states that the flow of water through a porous medium is?
a. Proportional to the medium’s hydraulic conductivity
b. Inversely proportional to the length of flow path
c. Both a and b
d. Neither a nor b
c. Both a and b
It is the ratio of the volume of voids to the total volume of the soil.
a. Void volume
b. Bulk density
c. Porosity
d. Void density
c. Porosity
It is the water retained about individual soil particles by molecular action and can be removed only by heating.
a. Permanent wilting point
b. Hygroscopic water
c. Hydrophobic water
d. Microscopic water
b. Hygroscopic water
It refers to the composite parts of the irrigation system that divert water from natural bodies of water such as rivers, streams and lakes.
a. Main canal
b. Diversion canal
c. Irrigation structures
d. Headworks
d. Headworks
It is a measure of the amount of water that the soil will retain against a tension of 15 atmospheres.
a. Readily available moisture
b. Permanent wilting point
c. Available moisture
d. Field capacity
b. Permanent wilting point
The International Soil Science Society describes sand as a soil particle with a diameter of
a. 0.02 to 2 mm
b. 0.2 to 2 mm
c. 0.002 to 0.02 mm
d. 0.002 to 0.2 mm
b. 0.2 to 2 mm
The localized lowering of the static or piezometric water level due to pumping.
a. Groundwater decline
b. Drawdown
c. Subsidence
d. Depression
b. Drawdown
Any convenient level surface coincident or parallel with mean sea level to which elevations of a particular area are referred
a. Datum
b. Elevation
c. Horizontal surface
d. Slope
a. Datum
It is a geologic formation which transmits water at a rate insufficient to be economically developed for pumping.
a. Aquifer
b. Aquiclude
c. Aquifuge
d. Aquitard
b. Aquiclude
It is the ratio of the dry weight of the soil to the weight of the water with volume equal to the soil bulk volume.
a. Particle density
b. Bulk density
c. Real specific gravity
d. Apparent specific gravity
d. Apparent specific gravity
It accounts for the losses in an irrigation system from the water source and prior to delivery of water into the field ditches.
a. Evaporation
b. Application efficiency
c. Diversion efficiency
d. Conveyance efficiency
d. Conveyance efficiency
A geologic formation that contains water but do not have the capacity to transmit it.
a. Aquifuge
b. Aquifer
c. Aquitard
d. Aquiclude
d. Aquiclude
What is the recommended value for standing water during land
preparation.
a. 5 mm
b. 10 mm
c. 15 mm
d. 8 mm
b. 10 mm
Farm water requirement minus the application losses is the.
a. Diversion water requirement
b. Farm irrigation requirement
c. Application efficiency
d. Land preparation water requirement
b. Farm irrigation requirement
This results from overlapping radii of influence of neighboring wells.
a. Drawdown
b. Groundwater decline
c. Well interference
d. Drawdown curve
c. Well interference
In furrow irrigation, the rate of water application should be ____ the intake rate of the soil.
a. Less than
b. Greater than
c. Equal to
d. Not related to
a. Less than
Irrigation method is used for row crops wherein only a part of the surface is wetted
a. Basin flooding
b. Furrow irrigation
c. Border irrigation
d. Border-strip flooding
b. Furrow irrigation
The amount of drainage water to be removed per unit time per unit area is the
a. Drainage requirement
b. Drainage coefficient
c. Drain spacing
d. Drainage volume
b. Drainage coefficient
In Hooghoudt’s drain spacing formula, it is assumed that
a. The water table is in equilibrium with the rainfall or irrigation water
b. The drains are evenly spaced
c. Darcy’s law is valid for flow through soils
d. All of the above
d. All of the above
A mathematical expression for the macroscopic flow of water through a porous system
a. Steady state groundwater flow equation
b. Darcy’s Law
c. Laplace’s equation
d. Scobey;s equation
b. Darcy’s Law
It is the soil moisture constant describing the amount of moisture retained by the soil against a suction pressure of 1/3 atmosphere
a. Field capacity
b. Hygroscopic water
c. Permanent wilting point
d. Saturation point
a. Field capacity
Run-off is the difference between the gross depth of irrigation water and the
a. Net depth requirement
b. Crop evapotranspiration
c. Depth that infiltrated
d. Water use rate
a. Net depth requirement
It is the type of sprinkler irrigation system where the number of laterals installed is equal to the total number of lateral positions
a. Hand move system
b. Periodic move
c. Special type
d. Set system
d. Set system
It is a surface irrigation system where the area is subdivided by dikes and water flows over these dikes from one subdivision to another.
a. Border irrigation
b. Furrow irrigation
c. Basin irrigation
d. Corrugation irrigation
c. Basin irrigation
Distribution control structures placed across an irrigation ditch to block the flow temporarily and to raise the upstream water level.
a. Turnouts
b. Checks
c. Culverts
d. Weirs
b. Checks
Which is not a component of the impact arm of an impact sprinkler?
a. Nozzle
b. Counterweight
c. Vane
d. Spoon
a. Nozzle
In surface irrigation, the ratio between the gross amount of irrigation water and the net requirement of the crop is the
a. Application efficiency
b. Deep percolation
c. Seepage
d. Runoff
a. Application efficiency
It is an orderly sequence of planting crop in an area for a 365-day period
a. Cropping pattern
b. Crop combination
c. Crop sequence
d. Cropping schedule
a. Cropping pattern
In furrow irrigation, it is the difference between the depth of water that infiltrated and the net depth requirement
a. Runoff
b. Application losses
c. Deep percolation
d. Seepage
c. Deep percolation
In-line canal structure designed to convey canal water from a higher level to a lower level, duly dissipating the excess energy resulting from the drop in elevation
a. Drop
b. Flume
c. Weir
d. None of the above
a. Drop
Amount of rainwater that falls directly on the field and is used by the crop for growth and development excluding deep percolation, surface runoff and interception
a. Average rainfall
b. Effective rainfall
c. Rainfall depth
d. None of the above
b. Effective rainfall
Applicator used in drip, subsurface, or bubbler irrigation designed to dissipate pressure and to discharge a small uniform flow or trickle of water at a constant rate that does not vary significantly because of minor differences in pressure
a. Drippers
b. Emitters
c. Nozzle
d. None of the above
b. Emitters
Closed conduit designed to convey canal water in full and under pressure running condition, to convey canal water by gravity under roadways, railways, drainage channels and local depressions
a. Siphon
b. Inverted siphon
c. Elevated flumes
d. None of the above
b. Inverted siphon
Amount of water required in lowland rice production which includes water losses through evaporation, seepage and percolation and land soaking
a. Land soaking water requirements
b. Land preparation water requirements
c. Irrigation water requirements
d. None of the above
b. Land preparation water requirements
Portion of the pipe network between the mainline and the laterals
a. Connector
b. Valve
c. Manifold
d. None of the above
c. Manifold
Constant flow depth along a longitudinal section of a channel under a uniform flow condition
a. Normal depth
b. Critical depth
c. Uniform depth
d. None of the above
a. Normal depth
Water flow that is conveyed in such a manner that top surface is exposed to the atmosphere such as flow in canals, ditches, drainage channels, culverts, and pipes under partially full flow conditions
a. Open channel flow
b. Canal flow
c. Pipe flow
d. None of the above
a. Open channel flow
Tube or shaft vertically set into the ground at a depth that is usually less than 15 m for the purpose of bringing groundwater into the soil surface whose pumps are set above the water level
a. Shallow tubewell
b. Deep well
c. Pipe
d. None of the above
a. Shallow tubewell
Ratio of the horizontal to vertical dimension of the channel wall
a. Slope
b. Channel gradient
c. Side slope
d. All of the above
c. Side slope
Slope of the water surface profile plus the velocity head in open channels
a. Energy grade line slope
b. Water surface slope
c. Channel bottom slope
d. Hydraulic grade line slope
a. Energy grade line slope
Slope of the free water surface in open channel
a. Energy grade line slope
b. Water surface slope
c. Channel bottom slope
d. Hydraulic grade line slope
d. Hydraulic grade line slope
Occurs when flow has a constant water area, depth, discharge, and average velocity through a reach of channel
a. Normal flow
b. Critical flow
c. Uniform flow
d. Varied flow
c. Uniform flow
Accounting of water inflows, such as irrigation and rainfall; and outflows, such as evaporation, seepage and percolation.
a. Water cycle
b. Water balance
c. Water flow
d. All of the above
b. Water balance
Area which contributes runoff or drains water into the reservoir.
a. Watershed
b. River network
c. Streams
d. All of the above
a. Watershed
Diameter of the circular area wetted by the sprinkler when operating at a given pressure and no wind.
a. Wetted diameter
b. Wetted perimeter
c. Diameter of throw
d. All of the above
a. Wetted diameter
Portion of the perimeter of the canal that is in contact with the flowing water.
a. Wetted diameter
b. Wetted perimeter
c. Diameter of throw
d. All of the above
b. Wetted perimeter
Moisture left in the soil before the initial irrigation water delivery which describes the extent of water depletion from the soil when the water supply has been cut-off.
a. Current soil moisture content
b. Residual moisture content
c. Allowable moisture depletion
d. None of the above
b. Residual moisture content
Pressure required to overcome the elevation difference between the water source and the sprinkler nozzle, to counteract friction losses and to provide adequate pressure at the nozzle for good water distribution.
a. Average pressure
b. Design pressure
c. Pressure requirement
d. None of the above
b. Design pressure
An overflow structure built perpendicular to an open channel axis to measure the rate of flow of water.
a. Weir
b. Flume
c. Orifice
d. None of the above
a. Weir
In-line structure with a geometrically specified constriction built in an open channel such that the center line coincides with the center line of the channel in which the flow is to be measured.
a. Weir
b. Flume
c. Orifice
d. None of the above
b. Flume
Measuring device with a well-defined, sharp-edged opening in a wall through which flow occurs such that the upstream water level is always well above the top of this opening.
a. Weir
b. Flume
c. Orifice
d. None of the above
c. Orifice
A device with individual scales on the rods to provide data to plot
furrow depth as a function of the lateral distance where data can then be numerically integrated to develop geometric relationships such as area verses depth, wetted perimeter versus depth and top-width vs depth.
a. Infiltrometer
b. Profilometer
c. Penetrometer
d. None of the above
b. Profilometer
Application of water by gravity flow to the surface of the field.
a. Surface irrigation
b. Furrow irrigation
c. Basin irrigation
d. None of the above
a. Surface irrigation
Method of irrigation where water runs through small parallel channels as it moves down the slope of the field.
a. Surface irrigation
b. Furrow irrigation
c. Basin irrigation
d. None of the above
b. Furrow irrigation
Recommended slope for furrow irrigation method.
a. 0.05 % to 3.0 %
b. 2.0% to 5.0%
c. ≤ 0.1%
d. None of the above
a. 0.05 % to 3.0 %
Any barrier constructed to store water.
a. Reservoir
b. Dam
c. Tank
d. None of the above
b. Dam
Volume of water stored in reservoir between the minimum water level
and normal water level.
a. Active storage
b. Dead storage
c. Storage capacity
d. None of the above
a. Active storage
Maximum elevation the water surface which can be attained by the dam or reservoir without flow in the spillway.
a. Maximum storage elevation
b. Dam crest elevation
c. Normal storage elevation
d. None of the above
c. Normal storage elevation
Part of water impounding system that stores the runoff.
a. Watershed
b. Reservoir
c. Dam
d. None of the above
b. Reservoir
Irrigation systems that have relatively large service areas and are managed by government agencies.
A. Shallow Tubewell Irrigation Systems
C. Communal Irrigation Systems
B. On-Farm Irrigation Facilities
D. National Irrigation Systems
D. National Irrigation Systems
A major irrigation system managed by the national irrigation administration.
A. Communal irrigation system
C. Main canal
B. Secondary canal
D. National irrigation system
D. National irrigation system
Composite facilities that permit entry of water to paddy areas and consist of farm ditches and turnouts.
A. Shallow Tubewell Irrigation Systems
C. Communal Irrigation Systems
B. On-Farm Irrigation Facilities
D. National Irrigation Systems
B. On-Farm Irrigation Facilities
Pipes vertically set into the ground that abstract groundwater to be used for irrigation, usually owned and
operated by individual farmers.
A. Shallow Tubewell Irrigation Systems
C. Communal Irrigation Systems
B. On-Farm Irrigation Facilities
D. National Irrigation Systems
A. Shallow Tubewell Irrigation Systems
An irrigation system that is managed by a bonafide irrigators’ association.
A. Headworks
C. Shallow tubewell
B. Communal irrigation system
D. National irrigation system
B. Communal irrigation system
A system of irrigation facilities covering contiguous areas.
A. Irrigators’ Association
C. Irrigated Lands
B. Irrigation System
D. Irrigable Lands
B. Irrigation System
Lands serviced by natural irrigation or irrigation facilities. These include land where water is not readily available as existing irrigation facilities need rehabilitation or upgrading or where irrigation water is not available year-round.
A. Irrigators’ Association
C. Irrigated Lands
B. Irrigation System
D. Irrigable Lands
C. Irrigated Lands
Lands which display marked characteristics justifying the operation of an irrigation system.
A. Irrigators’ Association
C. Irrigated Lands
B. Irrigation System
D. Irrigable Lands
D. Irrigable Lands
An association of farmers within a contiguous area served by a national irrigation system or communal
irrigation system.
A. Irrigators’ Association
C. Irrigated Lands
B. Irrigation System
D. Irrigable Lands
A. Irrigators’ Association
A principle of English Common Law which recognizes the right of riparian owner to make reasonable use of streamflow provided the water is used on riparian land.
A. Riparian Act
C. Exec. Order on Riparian Right
B. Riparian right
D. Presid’l Decreee on Riparian Right
A. Riparian Act
Farm turnout requirements plus conveyance losses in the main canal and lateral up to the farm turnout.
A. Diversion Water Requirement
C. Irrigation Water Requirement
B. Farm Water Requirement
D. Crop Water Requirement
A. Diversion Water Requirement
The water right based on the concept first time, first in right:
A. Right of way
C. General Appropriation
B. Appropriation Act
D. None of these
B. Appropriation Act
Similar to that of tertiary canals, the main systems (main and secondary canals) also incur losses termed as conveyance losses. Seepage and percolation losses and evaporation along the conveyance canals comprise the conveyance losses.
A. Diversion Water Requirement
C. Irrigation Water Requirement
B. Farm Water Requirement
D. Crop Water Requirement
A. Diversion Water Requirement
The crop water requirement of an area grown to a certain crop refers to the amount of water used for the non-consumptive demands such as land soaking and land preparation, and for the consumptive demands such as evapotranspiration requirements of the crop during its entire growth period.
A. Diversion Water Requirement
C. Irrigation Water Requirement
B. Farm Water Requirement
D. Crop Water Requirement
D. Crop Water Requirement
The sum of evapotranspiration and percolation losses.
A. Diversion Water Requirement
C. Irrigation Water Requirement
B. Farm Water Requirement
D. Crop Water Requirement
D. Crop Water Requirement
The ____ is the amount of water to be applied to the field as irrigation.
A. Diversion Water Requirement
C. Irrigation Water Requirement
B. Farm Water Requirement
D. Crop Water Requirement
C. Irrigation Water Requirement
The quantity of water exclusive of precipitation required to maintain desired soil moisture and salinity level during the crop season.
A. Diversion Water Requirement
C. Irrigation Water Requirement
B. Farm Water Requirement
D. Crop Water Requirement
C. Irrigation Water Requirement
Farm water requirement minus the application losses is the_______.
A. Diversion Water Requirement
C. Application efficiency
B. Farm irrigation requirement
D. Land preparation water requirement
B. Farm irrigation requirement
The sum of irrigation requirement and farm ditch losses.
A. Diversion Water Requirement
C. Irrigation Water Requirement
B. Farm Water Requirement
D. Crop Water Requirement
B. Farm Water Requirement
The fraction of the irrigation water that must be leached through the root zone to control soil salinity at specified level.
A. Leaching Requirement
C. Farm Water Requirement
B. Irrigation Water Requirement
D. Crop Water Requirement
A. Leaching Requirement
Amount of water required in lowland rice production which includes water losses through evaporation, seepage and percolation and land soaking.
A. Land soaking water requirements
C. Irrigation Water Requirement
B. Land preparation water requirements
D. None of these
B. Land preparation water requirements
Washing salt from the soil by using excess water to dissolve and carry each beyond the root zone.
A. Leaching
C. Blanching
B. Bleaching
D. None of these
A. Leaching
Includes evaporation and transpiration, lumped together as evapotranspiration.
A. Irrigation water requirement
C. Non-consumptive
B. Consumptive
D. Crop water requirement
B. Consumptive
Include seepage and percolation losses.
A. Irrigation water requirement
C. Non-consumptive
B. Consumptive
D. Crop water requirement
C. Non-consumptive
It also refers to consumptive use by crops.
A. Evapotranspiration
C. Water circulation
B. Saturation vapor pressure
D. Osmosis
A. Evapotranspiration
Is the sum of transpiration and water evaporated from the soil, or exterior portions of the plants where water may have accumulated from irrigation, rainfall, dew, or exudation from the interior of the plants.
A. Evapotranspiration
C. Transpiration
B. Percolation
D. Seepage
A. Evapotranspiration
The rate of evapotranspiration of vigorously growing crop that completely shades the ground and is adequately supplied with soil moisture is:
A. Actual crop evapotranspiration
C. Potential evapotranspiration
B. Reference crop evapotranspiration
D. Crop water requirement
C. Potential evapotranspiration
Ratio of the actual crop evapotranspiration to its potential evapotranspiration.
A. Crop ratio
C. Crop coefficient
B. ET ratio
D. Evaporation ratio
C. Crop coefficient
The crop coefficient used for estimating actual crop evapotranspiration is:
A. Constant throughout the growing period
B. Increases during the vegetative stage until ripening
C. Increases during flowering
D. Increases during vegetative stage until flowering and decreases towards ripening
D. Increases during vegetative stage until flowering and decreases towards ripening
It is the most elaborate method of computing potential evapotranspiration.
A. Blaney-Criddle
C. Jensen-Haise
B. Hargreaves
D. Penman
D. Penman
Irrigation before final seedbed preparation and planting; a method to insure adequate moisture for the germination of crop seeds.
A. Drip-irrigation
C. Pre-irrigation
B. Intermittent
D. Post-irrigation
C. Pre-irrigation
Wherein the surface is rarely wet since the water is supplied from the soil underneath.
A. Sprinkler irrigation
C. Drip or trickle irrigation
B. Sub-irrigation
D. Contour-ditch irrigation
B. Sub-irrigation
It involves controlled flooding from field ditches along the contour of the land, which allows the water to flood down the slope between field ditches without employing dikes or other means that guide or restrict its movement.
A. Sprinkler irrigation
C. Level-border or basin irrigation
B. Sub-irrigation
D. Contour-ditch irrigation
D. Contour-ditch irrigation
Water is supplied to level plots surrounded by dikes or levees. This method is particularly useful on fine textured soils with low permeability, it is necessary to hold the water on the surface to secure adequate penetration.
A. Sprinkler irrigation
C. Level-border or basin irrigation
B. Sub-irrigation
D. Contour-ditch irrigation
C. Level-border or basin irrigation
It is a surface irrigation system where the area is subdivided by dikes and water flows over these dikes from one subdivision to another.
A. Border irrigation
C. Basin irrigation
B. Furrow irrigation
D. Corrugation irrigation
C. Basin irrigation
The most efficient trapezoidal cross section.
A. Width of the bottom = twice the depth
C. Width of the bottom = 4x the depth
B. Depth = twice the bottom width
D. Width of the top =2x the sum of sides
A. Width of the bottom = twice the depth
For the most efficient circular cross-section, semi-circle the hydraulic radius is equal to:
A. ¼ its radius
C. ½ its radius
B. its radius
D. ¼ its diameter
D. ¼ its diameter
A concept used to evaluate the losses of water during irrigation from the time it leaves that source to the
point of use.
A. Discharge flow rate
C. Drainage efficiency
B. Irrigation efficiency
D. None of these
B. Irrigation efficiency
It is the ratio of the production attained with the operating irrigation system, compared to the total production expected under ideal condition.
A. Irrigation frequency
C. Irrigation method
B. Irrigation efficiency
D. Irrigation period
B. Irrigation efficiency
Refers to the number of days between irrigation periods without rainfall.
A. Irrigation frequency
C. Irrigation method
B. Irrigation efficiency
D. Irrigation period
A. Irrigation frequency
In surface irrigation, the ratio between the gross amount of irrigation water and the net requirement of the crop is the _____.
A. Application efficiency
C. Seepage
B. Deep percolation
D. Runoff
A. Application efficiency
Accounting of water inflows, such as irrigation and rainfall; and outflows, such as evaporation, seepage
and percolation.
A. Water cycle
C. Water flow
B. Water balance
D. All of these
B. Water balance
The number of days allowed for operating irrigation to a given design area during the peak consumptive period of the crop being irrigated.
A. Irrigation frequency
C. Irrigation method
B. Irrigation efficiency
D. Irrigation period
D. Irrigation period
Amount of rainfall in the rootzone.
A. Consumptive use
C. Percolation
B. Seepage
D. Effective rainfall
D. Effective rainfall
The sum total of water lost in a given area thru transpiration from plants, evaporation from soil and water surface and for building tissues of plants.
A. Consumptive use
C. Deep percolation
B. Seepage
D. Runoff
A. Consumptive use
Facility for determining water consumptive use of crops in an open field.
A. Planimeter
C. Consumeter
B. Lysimeter
D. Crop meter
b. lysimeter
It is a measure of the amount of water that the soil will retain against a tension of 15 atmospheres.
A. Permanent wilting point
C. Available moisture
B. Field capacity
D. Readily available moisture
A. Permanent wilting point
The amount of moisture present in the soil given the percent Available Moisture (AM) content retained or used and the Field Capacity (FC) and Permanent Wilting Point (PWP), the Moisture Content (MC) of the soil can be computed using the equations.
A. Permanent wilting point
C. Available moisture
B. Computation of moisture content
D. Readily available moisture
B. Computation of moisture content
What is the term for capillary water in the smaller pore space of the soil?
A. Interception
C. Basin recharge
B. Depression storage
D. Soil moisture
d. soil moisture
Difference in moisture content of soil between field capacity and permanent wilting point.
A. Irrigation water requirement
C. Available moisture
B. Saturation capacity
D. Readily available moisture
C. Available moisture
That portion of the available moisture that is most easily extracted by plants; this is approximately 75% of the available moisture.
A. Permanent wilting point (or wilting coefficient)
C. Available moisture
B. Computation of moisture content
D. Readily available moisture
D. Readily available moisture
75% of available moisture is called:
A. Readily available moisture
C. Permanent wilting point
B. Hygroscopic water
D. None of these
A. Readily available moisture
The product of Available Moisture to the Percent Moisture Depletion.
A. Readily available moisture
C. Available Moisture
B. Moisture Allowed Deficit
D. None of these
B. Moisture Allowed Deficit
Moisture left in the soil before the initial irrigation water delivery which describes the extent of water depletion from the soil when the water supply has been cut-off.
A. Current soil moisture content
C. Allowable moisture depletion
B. Residual moisture content
D. None of these
B. Residual moisture content
The percentage of moisture on dry weight basis that is held against the pull of gravity, after drainage has ceased in a soil that has been saturated:
A. Wilting point
C. Hygroscopic coefficient
B. Air dry
D. Field capacity
D. Field capacity
Moisture content present in the soil when gravitational water removed is called:
A. Wilting point
C. Field capacity
B. Unavailable moisture
D. Hygroscopic moisture
C. Field capacity
The moisture content of the soil when tension is 1/3 atmosphere:
A. Wilting point
C. Field capacity
B. Saturation point
D. Hygroscopic moisture
C. Field capacity
The amount of moisture content that is left from the soil 2-3 days after heavy application of rain or irrigation water.
A. Wilting point
C. Field capacity
B. Excess water
D. Available water
C. Field capacity
The amount of water a soil profile will hold against drainage by gravity at a specified time (usually from
24 to 48 hours) after a thorough wetting.
A. Infiltration rate
C. Field capacity
B. Permeability
D. Volume of irrigation water
C. Field capacity
Determined by placing an air-dry soil in a nearly saturated atmosphere at 25°C until it absorbs no more water. This tension is equal to a force of 31 atm. Water at this tension is not available to plants.
A. Water tension
C. Wilting point
B. Hydroscropic coefficient
D. Hygroscropic coefficient
D. Hygroscropic coefficient
Volume of water to be applied to increase the soil moisture content from an initial to final value?
A. Infiltration rate
C. Field capacity
B. Permeability
D. Volume of irrigation water
D. Volume of irrigation water
The moisture content of the soil when the tension is 1.5 atmosphere.
A. Permanent wilting point
C. Field capacity
B. Saturation point
D. Wilting coefficient
B. Saturation point
The amount of water the soil profile will hold when all its pore spaces are filled up with water.
A. Infiltration rate
C. Permeability
B. Saturation point
D. Intake rate
B. Saturation point
The ability of the stream to provide water determines the extent of the total service area of a national irrigation system.
A. Secondary canal
C. Canal
B. Main canal
D. Canal capacity
D. Canal capacity