B. Irrigation and Drainage Engineering Flashcards
(314 cards)
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