Soil & Water Resources Development and Conservation, Irrigation, Drainage and Allied Subjects (HIGH PRIO) Flashcards by poodey pay

The recent monsoon rains have posted a nearly uniform rainfall intensity of 30 mm/hr over a 1,500-hectare watershed area in Central Luzon. If the runoff coefficient is 0.15, what is the runoff in m3/sec?
a. 18.75
c. 1.87
b. 187.5
d. 1.875

a. 18.75

Q = CiA
Q = (30 mm/hr)(1500 ha)(10000 m2/ha)(1 hr/3600s)(1m/1000mm)

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Ratio of the dry weight of soil particles to the weight of an equal volume of water
a. Particle Density
b. Bulk Density
c. Real specific Density
d. Apparent specific density

c. Real specific Density

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A television network is planning to air four 30-minute sitcoms namely: “Mana-Mana”, “Okidoki”, “Tanging Ama” and “Home Along da Sea”. In how many ways can the network arrange these sitcoms in a 7-9 pm time slot if “Mana-Mana” should be aired third?
a. 1
b.2
c.6
d.24

c.6

3! = 6

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An artesian well has a diameter of 10 cm. Under steady state condition, what is the expected discharge (lps) if the drawdown is 2.5 m and the radius of influence is 120 m? The aquifer’s hydraulic conductivity and thickness are 75 m/day and 4 m, respectively.
a. 7.01 lps
b. 8.01 lps
c. 9.01 lps
d. 10.01 lps

a. 7.01 lps

Q = 2pikt(deltah)//ln(re/rw)

Q = 2pi(75 m/day)(4 m)(2.5 m)/ln(120m/0.05m)

convert m3/day to lps

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For rolling areas and non-uniform distribution of gages, distance factor fixed by location of gages is used for analysis using this method.
a.Inverse Distance Ratio Method
b.Grid-Point Method
c.Isohyetal
d.Thiessen polygon

a.Inverse Distance Ratio Method

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What is the soil erosion of 10 T/ha/yr in mm/yr?Assume that the soil bulk density is 1.2 T/m3.
a. 0.083 mm/yr c.0.83 mm/yr
b. 8.33 mm/yr d.80.33 mm/yr

c.0.83 mm/yr

Soil erosion = (10T/ha/yr)/(1.2 T/m3)

convert units

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Which among the elements is a major element for plant nutrition?
a. Boron
b. Chlorine
c. Nitrogen
d. Silicon

c. Nitrogen

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The process of converting water and carbon dioxide into sugar using chlorophyll and light energy accompanied by the production of oxygen by green plants:
a. respiration
b. oxidation
c. transpiration
d. photosynthesis

d. photosynthesis

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An irrigation engineer, in his study, was able to establish that the irrigation requirement of crop XYZ is 6.5 mm/day. If the rootzone depth was estimated at 2 in. On the average, what should be the design discharge of a canal to be able to deliver the 5-day requirement of a 10 ha farm in 24 hours?
a. 31.62 lps
b. 47.62 lps
c. 57.62 lps
d. 37.62 lps

Q = (6.5 mm/day)(5 days)(10 ha)(10000 m2)/(24 hours)

Q = convert L/h to lps

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Total water yield from a storm for a given watershed
a. Surface runoff
b. Subsurface runoff
c. Groundwater runoff
d. Runoff volume

a. Surface runoff

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The gross application depth is 93mm to irrigate a crop with a crop coefficient of 0.9. The reference crop evapotranspiration is 6mm/day. If the application efficiency is 70%, the irrigation interval is.
a. 10days b.11days c.12days d.13days

c.12days

II = (dnet)/ETc

dnet = dgross x Ea

ETc = ETo x Kc

II = (93 mm x 0.7)/(6 mm/day x 0.9)

II = 12 days

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This resembles terracing in that the drainage ditches are constructed around the slope on a uniform grade according to the land topography.
a. Random ditch system
b. Double-main system
c. Interception or cross-slope system
d. Diversion or parallel ditch system

c. Interception or cross-slope system

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It is the soil moisture allowable depletion of most crops.
a. 50%
b. 20%
c. 80%
d. 100%

a. 50%

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Given the following data:
Evapotranspiration = 5 mm/day,
Percolation = 2mm/day,
Rainfall for November = 200 mm,
Effective rainfall for Nov. = 50%,
Soil Porosity = 60%,
Apparent Specific Gravity = 1.4,
Residual Soil Moisture = 15%,
Rootzone depth = 200mm,
Application efficiency = 75%,
Conveyance efficiency = 80%,
Ave. fraction of area covered = 0.5,
Dependable flow = 4.5 m/sec,
Duration of land soaking = 5 days
16. What is the net land soaking requirement?
a. 78 mm/day c. 15.6 mm/day
b. 7.8 mm/day d. 0.65 mm/day

c. 15.6 mm/day

LSR = (n-(AsxRMC))(DRZ)

LSR = (0.6 - (1.4 x 0.15))(200 mm)

LSR = 78 mm

NetLSR = 78 mm/5 days = 15.6 mm/day

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Wherein the surface is rarely wet since the water is supplied from the soil underneath
a. Sprinkler irrigation
b. Sub-irrigation
c. Drip or trickle irrigation
d. Contour-ditch irrigation

b. Sub-irrigation

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An internal condition of a seed or bud that prevents its prompt germinating or sprouting under normal growth conditions:
a. dormancy
b. diffusion
c. germination
d. dominant

a. dormancy

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The process of moisture lost of plants through the leaves:
a. germination
b. transpiration
c. oxidation
d. flowering

b. transpiration

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A natural body composed of a variable mixture of broken and weathered minerals and decaying organic matter and when containing the proper amount of air and water, supplies sustenance and gives mechanical support of plants:
a. fertilizer
b. soil
c. humus
d. mineral

b. soil

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A concrete lined canal is to convey water over a distance of 250 m from the well to a tomato farm. Drop in elevation is 0.5 m over the 250 m canal length and roughness coefficient, n, is 0.018. Estimate the bottom width of a rectangular canal with a depth of flowing water of 0.25 m if the hydraulic radius is equal to the area of flow.
a. b = 0.5 m
b. b = 50 m
c. b = 0.25 m
d. b = 25 m
The velocity of water in the canal is
a. 0.62 m/sec
b. 6.2 m/sec
c. 62 m/sec
d. 0.062 m/sec

a. b = 0.5 m
a. 0.62 m/sec

b=2d (most efficient)
A=bd
Then use Manning’s equation to find the velocity.

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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
b.Sub-irrigation
c.Level-border or basin irrigation
d.Contour-ditch irrigation

d.Contour-ditch irrigation system

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The volume of the soil sample during sampling was 85 cc and weight after drying in the area was 130g. The volume weight of the soil is
a. 1.5 g/cc
b. 1.75 g/cc
c. 1/25 g/cc
d. nota

a. 1.5 g/cc

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The percentage of moisture by weight of a soil sample of 85 cc with a dry weight of 130 if the weight of the sample before drying was 145 g.
a.12.5% b.10.5% c.9.5% d.11.5%

d.11.5%

MCm = 145-130/130 x 100 = 11.5%

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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 (DWR)
b. Farm Water Requirement (FWR)
c. Irrigation Water Requirement (IWR)
d. Crop Water Requirement (CWR)

a. Diversion Water Requirement (DWR)

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The common name for Capra hircus:
a. sheep b. pig c. mule d. goat

d. goat

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The discharge of first emitter in a dropper line is 12 lph. What is the allowable minimum discharge in the last emitter?
a.9.6 lph b.10.8 lph c.10.6 lph d.9.8 lph

Q2 = Q1(0.8)

a.9.6 lph

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The common name for Anser domesticus:
a. chicken
b. goose
c. duck
d. turkey

b. goose

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The ability of the stream to provide water determines the extent of the total service area of a national irrigation system
a. Secondary canal
b. Main canal
c. Canal
d. Canal capacity

d. Canal capacity

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Includes evaporation and transpiration, lumped together as evapotranspiration.
a. Irrigation water requirement (IWR)
b. Consumptive
c. Non-consumtive
d. Crop water requirement (CWR)

b. Consumptive

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What is the depth of flowing water in a trapezoidal canal with a side slope of 1:1 and base of 1.0 m if the stream velocity is 1 mps and the average discharge is 6 cms.
a. 1.0 m
b. 2.0 m
c. 3.0 m
d. 4.0 m

b. 2.0 m

Q = VA
A = bd + zd^2

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The ratio of the weight of water to the dry weight of the soil
a. Soil Texture
b. Soil Structure
c. Porosity
d. dry weight basis

d. dry weight basis

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The soil has a field capacity and permanent wilting point of 27% and 13%, respectively. What is the readily available moisture in cm of water per cm of soil if the bulk density is 1.25 g/cc?
a. 10.25 cm/m
b. 17.5 cm/m
c. 13.12 cm/m
d. 14.0 cm/m

RAM = 0.75AM
AM = FC - PWP
RAM = (0.75)(0.27 - 0.13)(1.25)(100 cm/m)
RAM = 13.125 cm/m

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Advanced stage of rill erosion. Rills when neglected develop in size and become gullies.
a. Slip erosions
b. Wind erosions
c. Stream bank erosion
d. Gully erosion

d. Gully erosion

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What discharge can be expected from an unconfined well 200 mm in diameter if the drawdown is 5 m in an aquifer saturated to a depth of 18 m? Assume the permeability and the radius of influence to be 20 m/day and 150 m, respectively.
a.14.3 lps b. 13.8 lps
c.15.4 lps d. 12.6 lps

c.15.4 lps

Q=[(pi)(20m/day)(18^2 - 13^2)/ln(150 m/0.1 m)

convert to lps

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Used for flood forecasting and water quality studies; watershed response time
a. Surface time
b. Time to peak
c. Recession time
d. Peak recession time

b. Time to peak

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The hydraulic radius of a pipe with a diameter of 12 mm.
a. 3 mm b. 12 mm c. 6 mm d. 4 mm

a. 3 mm

R = A/P
A = pi(d)^2/4
P = pi(d)

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This is suitable on flat, poorly drained soils that have numerous shallow depresssions.
a. Random ditch system
b. Double-main system
c. Interception or cross-slope system
d. Diversion or parallel ditch system

d. Diversion or parallel ditch system

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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
b. Sub-irrigation
c. Level-border or basin irrigation
d. Contour-ditch irrigation

c. Level-border or basin irrigation

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The most efficient trapezoidal cross section.
a. width of the bottom= twice the depth
b. depth = twice the bottom width
c. width of the bottom = 4x the depth
d. width of the top=2x the sum of sides

The most efficient trapezoidal cross section, from a hydraulic standpoint (i.e., the shape that provides maximum discharge for a given cross-sectional area and slope), has the following relationship:

a. width of the bottom = twice the depth

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Removal of water from the road area by the use of culverts, ditches, channels and other several structures
a. Crushed Gravel
b. Roadway Embankment
c. Course
d. Drainage

d. Drainage

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The fraction of the irrigation water that must be leached through the root zone to control soil salinity at specified level.
a. Leaching Requirement (LR)
b. Farm Water Requirement (FWR)
c. Irrigation Water Requirement (IWR)
d. Crop Water Requirement (CWR)

a. Leaching Requirement (LR)

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Water horsepower divided by pump efficiency, in decimal.
a. Stochastic process
b. Water horsepower
c. Brake horsepower
d. Barrow process

c. Brake horsepower

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This involves the averaging arithmetically all the rainfall depths measured by the rain gages within the area
a. Inverse Distance Ratio Method
b. Grid-Point Method
c. Thiessen polygon
d. Arithmetic mean

d. Arithmetic mean

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Given an irrigation depth of 30 cm and 10 hrs of irrigation time. Determine the discharge to irrigate a hectare of land.
a.100 m3/hr b. 10 m3/hr c.300 m3/hr d. 50 m3/hr

c.300 m3/hr

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Any open or close ground or surface for the passage of water.
a. Water way
b. Seepage
c. Percolation
d. Watershed

a. Water way

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An undisturbed soil sample 100 cc was gathered from a field 2 days after heavy rains when the soil moisture was expected to be at field capacity. The weight of the fresh sample was 176 g but was reduced to 142 g after oven drying. A second soil sample with a fresh weight and oven dried weight of 130 g and 116 g, respectively, was gathered 3 weeks later when the crop was observed to have a permanently wilted.
-Determine the bulk density in g/cc.
a.42 b.1.42 c.1.76 d.17.6
-Determine the apparent specific gravity.
a.1.42 b.1.42 c.1.76 d.17.7
-Determine the field capacity (dry basis).
a.19.32% b. 1.93% c. 23.94% d. 2.39%
-Determine the wilting point (dry basis).
a.1.2% b. 12% c. 10.77% d. 1.08%

b. 1.42 (142g/100cc)
b. 1.42 (1.42g/cc)/(1g/cc)
c. 23.94% ((176-142)/142)
b. 12% ((130-116)/116)

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Combination of sheet and splash erosion
a. Interrill erosion
b. Rill erosion
c. Gully erosion
d. Stream channel erosion

a. Interrill erosion

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A crop has a depth of 0.6 m. F.C. and W.P. are 16% and 8%, respectively. Bulk density is 1.25 g/cc. The desired allowable soil moisture deficit is 60% of the allowable moisture and the average is 6 mm/day.
-The depth of water to be stored in the rootzone per irrigation is:
a. 3.6 m b.0.036 m c.36 mm d. 36 cm
-The irrigation interval is:
a. 6 days b.5 days c.7 days d.8 days

b. 0.036 m or c. 36 mm
dnet = (FC - PWP)(AMD)(DRZ)(As)
dnet = (0.16-0.08)(0.6)(1.25)(0.6m)

a. 6 days
II = dnet/ETc
II = 36 mm/(6 mm/day)

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Caused by high velocity winds moving over barren land surfaces.
a. Slip erosions
b. Wind erosions
c. Coastal erosions
d. Stream bank erosion

b. Wind erosions

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Soil productivity is the ability of the soil
a. to produce the desired amount of plant yield
b. supply nutrients in sufficient and balanced amounts
c. store and resist leaching nutrients
d. all of the above

a. to produce the desired amount of plant yield

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The percent N, P2O5 and K2O in a fertilizer
a. fertilizer grade
b. fertilizer ratio
c. fertilizer recommendation
d. none of the above

a. fertilizer grade

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Which is not a single-element or straight fertilizer?
a. Urea
b. Muriate of Potash
c. Ammonium phosphate
d. Ammonium sulfate

c. Ammonium phosphate

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Given bed slope=0.0003; Manning’s coefficient, n=0.03; b/d ratio=3.5; wetted perimeter, p=14; z=0.5. The velocity of flow along a trapezoidal canal is:
a. 8.9 m/s b. 0.89 m/s c. 89 m/s d. 0.089 m/s

b. 0.89 m/s

Get d or b using the Perimeter then solve R = A/P. Then use Manning’s equation.

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Primarily caused by raindrop
a. Slip erosions
b. Wind erosions
c. Coastal erosions
d. Splash/Raindrop erosion

d. Splash/Raindrop erosion

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The thickness of a confined aquifer is 5 m, well diameter=40 cm, radius of influence=250 m, k=10 m/day, height of water in the pumping well=1,325 m, height of piezometric surface=1,500 m. The steady state discharge is:
a. 0.89 m3/sec
b. 0.089 m3/sec
c. 0.089 lps
d. 0.89 lps

b. 0.089 m3/sec

Q = [2pikt(h1-h2)]/ln(re/rw)

Q = [2pi(10m/day)(5m)(1500m-1325m)]/ln(250m/0.2m)

convert to lps

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Surface runoff plus interflow
a. Base flow
b. Direct runoff
c. Groundwater runoff
d. Peak flow

b. Direct runoff

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How many sprinklers with spacing of 7m x 7m are needed to irrigate a rectangular field of 150m x 200m if the laterals are set parallel to the larger side of the field:
a. 588 b. 609 c. 616 d. 638

a. 588

Total number of sprinklers = Nl x Ns
Nl = (150 m/7m) = 21 laterals
Ns = (200m/7m) = 28 sprinklers per lateral
TNOS = 21 x 28 =588 sprinklers

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The soil type largely influences the width of bed to be used. The furrows drain to collection ditches.
a. Random ditch system
b. Double-main system
c. Bedding system
d. Natural system

c. Bedding system

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The scientific name for pigeon:
a. Columbia livia
b. Anser domesticus
c. Gallus gallus
d. Numida meleagris

a. Columbia livia

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If the theoretical flow of velocity in an orifice is 4 m/s, what is the height of water flowing above the center of the orifice?
a. 0.8m b. 8.0m c. 0.9m d. 9.0m

a. 0.8m

V = sqrt(2gH)

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The needed for water to infiltrate into the soil, depending on the depth of water and the soil.
a. Infiltration rate
b. Infiltration
c. Infiltration efficiency
d. None of the above

a. Infiltration rate

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Irrigation systems that have relatively large service areas and are managed by government agencies
a. Shallow Tubewell Irrigation Systems (STW)
b. On-Farm Irrigation Facilities
c. Communal Irrigation Systems (CIS)
d. National Irrigation Systems (NIS)

d. National Irrigation Systems (NIS)

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Given an irrigation depth of 30 cm and 8 hrs of irrigation time. Determine the discharge needed to irrigate a hectare of land:
a. 375 m3/hr
b. 10 m3/hr
c. 30 m3/hr
d. 200 m3/hr

a. 375 m3/hr

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The soil moisture content when plants permanently wilt. The soil moisture
tension at this point is about 15 atmospheres.
a. Computation of moisture content
b. Readily available moisture (RAM)
c. Available moisture (AM)
d. Permanent wilting point (or wilting coefficient)

d. Permanent wilting point (or wilting coefficient)

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A flood flow of 560 m3/s was determined to have a 50% probability of occurrence. What is its return period?
a. 2 years c. 20 years
b. 5 years d. 50 years

a. 2 years

Probability = (1/Return Period) x 100

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Type of flow wherein the depth of flow in a prismatic channel is constant at any point in the channel
a. laminar flow
b. uniform flow
c. steady flow
d. critical flow

b. uniform flow

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Urea is one of the many form of commercial fertilizers with a typical grade of ______?
a. 14-14-14
b. d. 0-0-60
c. 45-0-0
d. 0-30-0

c. 45-0-0

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The study of soil which puts more emphasis on the origin, characteristics, classification and description:
a. Pedology
b. Botany
c. Pathology
d. Agronomy

a. Pedology

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The unit of heredity, variation, sex determination and related phenomena:
a. plasma
b. protein
c. gene
d. cell

c. gene

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A farmer is to irrigate a crop planted in furrows of 100m x 100m area. His furrow spacing is 50 cm and the application depth is 100 mm. If the
inflow rate is 0.4 lps/100m, determine the time of irrigating each furrow:
a. 3.47 hrs b. 0.69 hrs c. 28.94 hrs d. 15 days

a. 3.47 hrs

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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
b. Irrigation System
c. Irrigated Lands
d. Irrigable Lands

c. Irrigated Lands

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This property of run-off is used for flood forecasting and water quality analysis. It is the time where the flood flow is highest.
a. Recession time
b. Time to lag
c. Run-off time
d. Time to peak

d. Time to peak

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A rectangular lined canal will be used to irrigate 60 has. If a Francis weir of 0.4m crest will be used to control the flow, what would be the depth of water over the crest in order to supply 2 lps/ha?
a. 0.07m b. 0.30m c. 1.94m d. 4.47m

a. 0.07m

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The ratio of water beneficially used on the project, farm or field to the amount of water delivered to the farm expressed in percent.
a. Consumptive use efficiency
b. Water storage efficiency
c. Water-use efficiency
d. Water application efficiency

c. Water-use efficiency

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A type of terrace usually used for 9-24% slope characterized by breaking the slope at certain intervals by a ridge and a flat portion to trap runoff.
a. Bench terrace
b. Zingg terrace
c. Broad-based terrace
d. Manning’s terrace

b. Zingg terrace

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The operating pressure of the sprinkler heads in a sprinkler irrigation system is 12.52 kg/cm2. What is the allowable pressure (kg/m2) variation between the first and the last sprinkler head in a lateral?
a. 2.504 b. 5.240 c. 25.04 d. 4.520

a. 2.504

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The ratio of the void volume to the total soil volume (unitless)
a. Soil Texture
b. Soil Structure
c. Porosity
d. dry weight basis

c. Porosity

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Ratio of the bulk density of the soil with the density of water; it is the ratio of the weight of soil to the weight of water with volume equal to the total soil volume
a. Bulk density
b. Particle density
c. Apparent specific gravity
d. Real specific gravity

c. Apparent specific gravity

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A rectangular water tank, 2 meters high, is filled with water. Due to rust, a circular hole was made on lowest portion of one side of the tank. Considering that the tank is maintained full, what is the velocity of water right after its take-off from the hole?
a. 6.26 m/s
b. 39.22 m/s
c. 4.43 m/s
d. 19.63 m/s

a. 6.26 m/s

V = sqrt(2gH)

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If the speed of an irrigation centrifugal pump is increased by 30%, the power requirement is increased by:
a. 2.197 b. 1.297 c. 2.917 d. 1.972

a. 2.197

P1(n2/n1)^3 = P2

P1(1.3/1)^3 = P2

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Include seepage and percolation losses.
a. Irrigation water requirement (IWR)
b. Consumptive
c. Non-consumptive
d. Crop water requirement (CWR)

c. non-consumptive

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A farm ditch has depth of flowing water of 60cm, bottom width=50 cm, side slope=1horizontal:1vertical, channel slope=0.02%.
1. The velocity of flow in m/sec is:
a. 0.143 b. 0.0134 c. 0.314 d. 0.431
2. The discharge in m3/sec is:
a. 0.027 b. 0.207 c. 0.702 d. 0.072

c) 0.314
b) 0.207

Use n = 0.02, however, based on PAES 603:2016 the roughness coefficient for common farm ditch is 0.03. Either way, the closest answer is letter c for velocity.

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Determine the size of a pump to irrigate a 5-ha riceland. The water source is a stream with pumping head of 2 m.
Evaporation=8mm/day;
Percolation=2mm/day;
Irrigation interval=5 days
Irrigation period=10 hrs; Friction loss=0;
Pump efficiency=80%
Irrigation efficiency=80%.
a. 2.129 hp b. 2.85 hp c. 5 hp d. 1.5 hp

b. 2.85

Crop water requirement = 8mm/day + 2mm/day

Volume required = (10mm/day)(5 days)(50000 m2)/irrigation efficiency

Q = Volume required/irrigation period

P = QH/3960Eff = 2.85 hp

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Governed by chance; time dependent
a.Stochastic process
b.Probabilistic process
c.Deterministic process
d.Barrow process

a.Stochastic process

a.Stochastic process - future outcome is not completely predictable, hence, governed by chance.
b.Probabilistic process - a more general term, stochastic is a type of probabilistic.
c.Deterministic process - future outcome is completely predicted/determined.
d.Barrow process - distractor. There is no widely recognized “Barrow process” in the fields of probability or systems governed by chance.

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b. 0.19125 lps

Q = intake rate (sprikler spacing)
Q = 8.5 mm/hr(9mx9m)(1hr/3600s) = 0.19125 lps

*meters x meters x millimeters = liters

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Interval between corresponding points on successive terraces
a.Horizontal interval
b.Vertical Interval
c.Contour line
d.Contour topography

a.Horizontal interval

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It is a variation of the furrow method and it uses small rills or corrugations for irrigating closely spaced crops, such as small grains and pastures.
a.Sprinkler irrigation
b.Sub-irrigation
c.Drip or trickle irrigation
d.Corrugation irrigation

d.Corrugation irrigation

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A farmer proposes to use sprinkler on a rectangular field 160m x 120m with lateral line parallel to the shorter side. The land is adjacent to the river from which he pumps water. He needs a maximum application depth of 60 mm every 10 days. The maximum intake rate of the soil is 8.5 mm/hr and the application efficiency is 80%. Sprinkler spacing is 9m x 9m.
How many sprinklers are in a lateral?
a. 13 b. 18 c. 14 d. 17
How many number of lateral positions?
a. 13 b. 18 c. 14 d. 17
How many hours will it take him to apply the water requirement in one
lateral position?
a. 7.06 hrs b. 10 days c. 2 hrs d. 8.82 hrs
What is the required pump discharge in lps?
a. 45.53 b. 3.4 c. 2.55 d. 25.5

a) 13
d) 17
d) 8.82 hrs
dg=dnet/Ea, IP=dg/r
r = 8.5 mm/hr, dnet = 60 mm
a) 45.53
Qsys = Nl x Ns x qs

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What should be the diameter of a pipe such that the two of them will be just sufficient to hold the water in an open canal 2m wide and 1m deep? Assume half square section canal and use a common slope of 0.0007 and Chezy’s
coefficient = 58.
a. 1.26 m b. 1.8 m c. 1.085 m d. 1 m

a. 1.26 m

2Qpipe = Qcanal

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Measures the velocity of a floating object preferably in a straight section of a stream
a. Float method
b. Float type water stage recorder
c. Bubbler gage
d. Crest stage gage

a. Float method

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The following depths of water penetration in meters were observed at 10m interval along a furrow irrigation system:0.65, 0.66, 0.68,0.72, 0.73, 0.77, 0.78, 0.80, 0.82, and 0.86. The uniformity coefficient is.
a. 92% b.79% c.96% d.86%

a. 92%

UC = 1 - y/d
y = average deviation from the mean depth
d = mean depth

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Given the soil sampler with a diameter of 5.2 cm and length of 4.7 cm. What is the bulk volume of soil it could gather?
a.100 cc b. 95 cc c. 120 cc d. 24.4 cc

a.100 cc

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A crop grown between orchard trees or on field between cropping season to protect the land from leaching and erosion:
a. cover crop
b. inter-tilled crop
c. cash crop
d. companion crop

a. cover crop

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A crop which is planted in shortly before the first crop is to be harvested:
a. inter-tilled crop
b. cash crop
c. relay crop
d. companion crop

c. relay crop

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The science or study of disease, its causes, and its controls:
a. Agrometeorology
b. Horticulture
c. Pathology
d. Botany

c. Pathology

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An engineer is to design the mainline of a sprinkler system which will use a steel (Scobey’s coefficient K = 0.40) to carry a flow of 6.5 lps. The length of pipe is 150m and the inside diameter is 100 mm. Compute the head
loss of the system assuming a uniform flow.
a. 3.16 m b. 1.36 m c. 1.5 m d. 1.8 m

b. 1.36 m

Hf = k[(L)(Q)^1.9]/D^4.9 x (4.10 x 10^6)

L = meters
Q = lps
D = mm

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A practical adaptation of reforestation whereby the species planted have economic value, such as mango, pili and so on.
a. Cropping systems
b. Strip cropping
c. Agroforestry
d. Reforestation

c. Agroforestry

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What is the evapotranspiration of corn during its growing period if the crop coefficient is 2.5 and the reference crop evapotranspiration is 6 mm/day?
a. 2.44 mm/day b. 0.42 mm/day
c. 8.5 mm/day d. 15 mm/day

d. 15 mm/day

ETa = ETo x Kc

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The composite parts of the irrigation system that divert water from natural bodies of water such as rivers, streams, and lakes
a. Headworks
b. Communal irrigation system
c. Secondary canal
d. Main canal

a. Headworks

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The scientific name of strawberry:
a. Vitis vinifera
b. Sandorium koetjape
c. Cocos nucifera
d. Fragaria vesca

d. Fragaria vesca

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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 (DWR)
b. Farm Water Requirement (FWR)
c. Irrigation Water Requirement (IWR)
d. Crop Water Requirement (CWR)

d. Crop Water Requirement (CWR)

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The soil has a field capacity of 30.8% volume basis and a permanent wilting point of 12% dry mass basis. The apparent specific gravity is 1.4. If the rootzone depth is 1.0m and the management allowable deficit is 50% the net application depth is.
a. 70mm b.60mm c.50mm d.40mm

a. 70mm

dnet=(FCv - PWPm x As)(DRZ)(AMD)

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Delivery of 360 cfs to an 80-acre field is continued for 4 hrs. Tail water flow is estimated at 10 cfs. Soil probing after the irrigation indicates that 1 ft. of water was stored in the rootzone. Compute the application efficiency.
a.60% b. 62% c. 92% d. 67%

d. 67%

Application efficiency only considers the overall delivery. Hence, no need to subtract tail water flow.

Ea = 360 cfs/(Area x depth)/Irrigation period

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The duration of irrigation application for a 1-ha cornfield for a given discharge of 100lps to obtain an average depth of application of 200mm assuming an application efficiency of 70% should be.
a. 8hrs b. 10hrs c. 12hrs d.14hrs

a. 8hrs

IP = (volume required)/discharge

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How much water is needed in each irrigation if the moisture holding capacity of the soil is 1.5 in/ft and irrigation was started when 40% is depleted. The crop uses 0.25 in/day of moisture and has a root depth of 3 ft.
If there is no rain, how often will irrigation be required?
a. 4.8 in. every 6 days b. 1.8 in. every 7.2 days
c. 2.8 in. every 4 days d. 3.8 in. every 5 days

Moisture holding capacity is the same as available water.

dnet = (1.5in/12in)(0.4)(3ft x 12 in/ft) = 1.8 in

II = dnet/ETc
II = 1.8 in/0.25 in/day
II = 7.2 days

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The name for seasonal winds (derived from Arabic mausim, a season)
a.trade winds
b.Monsoon winds
c.Valley winds
d.Mountain winds

b.Monsoon winds

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The Philippine Agricultural Engineering law of 1998.
a. RA 8559
b. RA 8599
c. RA 8995
d. RA 8595

a. RA 8559

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The Agriculture and Fisheries modernization act of 1998?
a. RA 8535
b. RA8435
c. RA8543
d. RA8453

b. RA8435

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A notch of regular form through which the irrigation stream is made to flow and built as either portable or stationary structure.
a. Parshall flume
b. Weir
c. Dam
d. Orifice

b. Weir

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Is soil detachment and transport resulting from the impact of water drops directly on soil particles or on thin water surfaces.
a. Interrill erosion
b. Rill erosion
c. Splash / raindrop erosion
d. Stream channel erosion

c. Splash / raindrop erosion

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Compute the water holding capacity of soil in inches if the F.C. is 30% and the wilting point is 15% of the dry soil density. This density is 80 lbs/ft3 and the soil depth to be irrigated is 2 feet.
a. 3.6 b. 2.6 c. 5.6 d. 4.6

d. 4.6 inches

dnet = (FC - PWP)(As)(DRZ)

As = 80 lbs/ft3 / density of water (62.4 lbs/ft3)

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The mass per unit volume of the soil particle is:
a. Porosity
b. void ratio
c. soil density
d. specific gravity

a. Porosity

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Can stabilize the slopes of the gully and hence reduce runoff velocities.
a. Riprap
b. Grassed waterways
c. Check dams or weirs
d. Vegetation

b. Grassed waterways

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The trapezoidal canal is to have a base width of 6 m and side slopes of 1:1. The velocity of flow is 0.6 m/sec. What slope must be given the bed in order to deliver 5 m3/sec and n=0.025.
a. 0.00263 b. 0.0000263 c. 0.000263 d. 0.0263

c. 0.000263

calculate area, Q=VA
then calculate d

then calculate R

then solve for slope

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Caused by the rising of warmer, lighter air in colder, denser surroundings.
a. Frontal
b. Convective precipitation
c. Cyclonic precipitation
d. Orographic precipitation

b. Convective precipitation

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Landslides and slips due to saturation of steep hills and slopes.
a.Slip erosions
b.Wind erosions
c.Coastal erosions
d.Stream bank erosion

a.Slip erosions

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Given a probability of occurrence or exceedence of 5%. How many years will it take before a discharge of 1000 m3/sec will be equaled or exceeded?
a. 10 b. 15 c. 20 d. 25

c. 20

T = 1/P
T = 1/0.05

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Composite facilities that permit entry of water to paddy areas and consist of farm ditches and turnouts
a. Shallow Tubewell Irrigation Systems (STW)
b. On-Farm Irrigation Facilities
c. Communal Irrigation Systems (CIS)
d. National Irrigation Systems (NIS)

b. On-Farm Irrigation Facilities

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Given the following: bed slope = 0.0003 manning constant, n= 0.03 b/d ratio = 3.5 wetted perimeter = 14; z = 0.5. The velocity of flow along a trapezoidal canal is?
a. 8.2 m/s
b. 0.82 m/s
c. 82 m/s
d. 0.082 m/s

b. 0.82 m/s

solve d using b/d ratio and the perimeter
Then solve for R.
Then solve V.

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It is accomplished by running water through small channels or furrows while it moves down or across the slope of the field.
a. Corrugation irrigation
b. Furrow irrigation
c. Level-border or basin irrigation
d. Contour-ditch irrigation

b. Furrow irrigation

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The recommended flow velocity on earth canals is.
a. 0.30-1.0 m/s
b. 1.0-2.0 m/s
c. 0.10-0.75 m/s
d. None of the above

a. 0.30-1.0 m/s

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Which is highly dependent on soil texture, refers to the downward movement of water through a depth of soil.
a. Percolation
b. Evapotranspiration
c. Transpiration
d. Seepage

a. Percolation - vertical/downward movement of water

Seepage - lateral movement of water

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A soil sample has wet mass of 120g and an undisturbed volume of 78cc. If the dry mass basis moisture content is 20%, the bulk density is.
a. 3.28g/cc
b. 1.28g/cc
c. 2.28g/cc
d. 4.28g/cc

b. 1.28g/cc

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If the rectangular canal have base of 0.65 m, what would be the depth of flow when the hydraulic radius is equal to the area of flow.
a. 0.418 m
b. 4.18 m
c. 0.17 m
d. 1.7 m

c. 0.17 m

R = A/P
R = (bd)/P
R = 0.65d/1

P = b + 2d
1 = 0.65 +2d
d = 0.175 m

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The ____ is the amount of water to be applied to the field as irrigation.
a. Diversion Water Requirement (DWR)
b. Farm Water Requirement (FWR)
c. Irrigation Water Requirement (IWR)
d. Crop Water Requirement (CWR)

c. Irrigation Water Requirement (IWR)

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A concrete lined canal is to convey water over a distance of 250 m, from the well to farm, drop in elevation is 0.50 m over canal length and roughness coefficient, n=0.018. Estimate the bottom width of a rectangular canal with a
depth of flowing water of 0.25 m, if the hydraulic radius is equal to the depth of flow?
a. 0.5 m
b. 5 m
c. 50 m
d. None of the above
What is the velocity of water in the canal in item above.
a. 0.062 m/s
b. 0.62 m/s
c. 6.2 m/s
d. 62 m/s

a) 0.5

R=d
R=0.25/1
1 = b + 2d
b = 1 - 2(0.25)
b = 0.5 m

b) 0.62 m/s

recompute R then use manning’s

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Graphs that show interrelations between speed, head discharge, and horsepower of a pump.
a. Static head
b. Total dynamic head
c. Drawdown
d. Characteristic curve

d. Characteristic curve

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The most hydraulically efficient trapezoidal channel section to carry a discharge of 5m3/s on a bed material with roughness n of 0.02 and a bottom slope of 1 in 800 should have a bottom width of.
a. 1.65m b. 2.65m c. 3.65m d. 4.65m

a. 1.65m

Solve d, then solve b.

A = 1.73d^2
R = d/2

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A discharge of 20 L/sec is equivalent to.
a. 2 cu.m/hr
b. 20000 cu.m/hr
c. 0.02 L/min
d. 72 cu.m/hr

d. 72 cu.m/hr

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That portion of the available moisture that is most easily extracted by plants; this is approximately 75% of the available moisture.
a. Computation of moisture content
b. Readily available moisture (RAM)
c. Available moisture (AM)
d. Permanent wilting point (or wilting coefficient

b. Readily available moisture (RAM)

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Given an irrigation depth of 30cm and 10 hrs of irrigation time, determine the discharge needed to irrigate a hectare of land
a. 100 cu.m/hr
b. 10 cu.m/hr
c. 30 cu.m/hr
d. 300 cu.m/h

d. 300 cu.m/h

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Associated with the movement of air masses from high-pressure to lowpressure regions
a. Frontal
b. Non Frontal
c. Cyclonic precipitation
d. Orographic precipitation

c. Cyclonic precipitation

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One liter per second is equal to.
a. 16.85 gpm
b. 15.5 gpm
c. 15.85 gpm
d. 17.35 gpm

c. 15.85 gpm

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Lands which display marked characteristics justifying the operation of an irrigation system
a. Irrigators’ Association
b. Irrigation System
c. Irrigated Lands
d. Irrigable Lands

d. Irrigable Lands

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A farm channel carries a flow of 20 L/s for a field using furrow irrigation. If each furrow required a flow of 1 L/s, how many furrow can be irrigated at a time?
a. 20
b. 200
c. 2000
d. NOTA

a. 20

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A method of asexual propagation involving the transfer of aerial parts of one plant (scion) to the root or trunk material (stock) of another plant:
a. Hydroponics
b. Grafting
c. Inoculation
d. Marcotting

b. Grafting

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The sequences of events occurring in a viable seed, starting with the inhibition of water, that leads to the growth and development of embryo:
a. Reproduction
b. Vegetative stage
c. Fertilization
d. Germination

d. Germination

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A crop produced for direct sale for cash, as contracted with crops produced
as livestock feed:
a. cover crop
b. inter-tilled crop
c. companion crop
d. cash crop

d. cash crop

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An unlined trapezoidal irrigation canal is to carry a maximum discharge of 2,800lps. The side slope is to be set at 1:1. The head loss over a 1km distance is 1m. The Manning’s roughness coefficient is 0.025. If the maximum
permissible velocity is 0.92m/s, the design depth should be.
a. 10.95m b. 0.95m c. 2.95m d. 5.95m

b. 0.95m

Maximum discharge means most efficient

for unlined canal
b = 4dtan(θ/2)
b = 4dtan(60/2)
b = 4sqrt(3)/3 d
A = bd +zd^2 ; A = Q/V

The ratio of the normal consumptive use of water to the net amount of water depleted from the root zone soil.
a. Consumptive use efficiency
b. Water storage efficiency
c. Water-use efficiency
d. Water application efficiency

a. Consumptive use efficiency

An agricultural engineer uses the quarter time rules in irrigating the field. If the contact time required to fill the soil reservoir is 1 day, how
long will the water reach the far end of the field
a. 240 min
b. 260 min
c. 360 min
d. 320 min

c. 360 min
quarter time
1 day = 24 hours
24/4 = 6 hours
6 hours = 360 mins

The ratio between water stored in the soil root zone during irrigation and the water delivered to the farm expressed in percent.
a. Consumptive use efficiency
b. Water storage efficiency
c. Water application efficiency
d. Water conveyance efficiency

c. Water application efficiency

An average depth of 100mm of water is needed to irrigate 5 ha of land in 20 hrs, what stream size is needed?
a. 6.95 L/s
b. 69.5 L/s
c. 695 L/s
d. 6950 L/s

b. 69.5 L/s

The velocity of flow into the soil caused by a unit hydraulic gradient in which the driving force is one kilogram per kilogram of water.
a. Infiltration rate
b. Intake rate
c. Permeability
d. Saturation point

c. Permeability

Seventy-five mm of water is needed to irrigate the field. In order to irrigate adequately over the whole area, an average depth of 100mm must be applied, how much water is lost.
a. 2.5mm
b. 25mm
c. 75mm
d. 7.5mm

b. 25mm

The time rate at which water will percolate into the soil and can be expressed in terms of the following empirical equations
a. Infiltration rate
b. Intake rate
c. Permeability
d. Saturation point

a. Infiltration rate

Suppose a farm channel 4km long with a cross sectional area of 0.75 sq.m is to be filled with water before irrigation can begin. How long will this take when the discharge is 30Lps?
a. 27 hours
b. 17 hours
c. 10 hours
d. 5 hours

a. 27 hours

Construction of earth embankment or ridge and channel across the slope at an acceptable grade to control the flow of runoff as well as soil particles.
a. Riprap
b. Gabions
c. Diversion canal
d. Terracing

d. Terracing

An 8 mm rainfall was measured by a USWB standard rain gauge, 8 inches in diameter. Determine the depth in the inner cylinder whose area is 1/10 of the catch area
a. 0.8 cm
b. 259 mm
c. 80 mm
d. 80 cm

c. 80 mm

solve volume of catchment (Vc)

Vc = Ac/10 (d)

A 30inch diameter 1-meter long culvert has been designed to carry a maximum discharge of 1.7m3/s when flowing half-full. Its roughness
coefficient n is 0.014. If the inlet and the outlet are both unsubmerged, the difference in elevation between the inlet and the outlet should be.
a. 10cm b. 20cm c. 30cm d.40cm

a. 10cm

Erosion caused by wave action on the seashore.
a. Slip erosions
b. Wind erosions
c. Coastal erosions
d. Stream bank erosion

c. Coastal erosions

Determine the 10 year period peak runoff for a 80ha watershed having a runoff coefficient of 0.4, maximum length of water is 610m and the fall along this path is 6m. The rainfall intensity for that return period is 101.25mm/hr having duration equal to the time of concentration.
a. 9.0
b. 1.5
c. 16.5
d. 16.3

a. 9.0

q=0.0028CIA
q - m3/s
C- runoff coefficient
I - rainfall intensity, mm/hr
A- area, ha

Combination and splash and sheet erosion
a. Slip erosions
b. Gully erosion
c. Rill erosions
d. Interrill erosions

d. Interrill erosions

The approximate threshold for the soil loss in the Philippines is around 12metric ton per hectare per year. Assuming a soil bulk density of 1.2 metric ton / cu. m, What is the soil erosion in mm/ yr.
a. 0.1 mm / yr
b. 1.0 mm / yr
c. 10 mm / yr
d. 100 mm / yr

b. 1.0 mm / yr

Time for surface and interflow to recede; duration of flooding
a.Surface time
b.Base time
c.Recession time
d.Surface interflow time

c.Recession time

The discharge in a triangular channel with a vertex angle of 90 degrees is 390lps. The critical depth is.
a. 0.5m b. 5m c. 2.0m d. 1.0m

a. 0.5m

check annotated HIGH PRIO 2 for clear solution.

Number 83 (AL-SAHID)

Same as groundwater runoff
a. Base flow
b. Subsurface runoff
c. Groundwater runoff
d. Runoff volume

a. Base flow

A flood flow of 560 cu.m per second was determined to have a 20% probability of occurrence. What is its return period?
a. 2 years
b. 5 years
c. 20 years
d. 50 years

b. 5 years

For a watershed of 360 ha, the peak runoff rate for 5 cm/hr rain intensity (at the time of concentration) was observed as 2.5 cu.m/s. What is the runoff coefficient?
a. 0.5
b. 0.005
c. 5.0
d. 0.05

d. 0.05

If the depth changes abruptly over a comparatively short distance such as in a hydraulic jump
a. Turbulent flow
b. Gradually varied flow
c. Rapidly varied flow
d. Unsteady flow

c. Rapidly varied flow

Is the detachment and transport of soil particles from the land by water or wind action.
a. Erodibility
b. Erosivity
c. Erosion
d. Soil erosion

d. Soil erosion

The theoretical flow velocity in an orifice is 4 m/s, what is the height of water flowing the center of the orifice?
a. 20.4 cm
b. 81.6 cm
c. 361.2cm
d. 90.3 cm

b. 81.6 cm

V = sqrt(2gH)

Which wets the entire land surface
a. Hose pipe
b. Watering can
c. Drainage
d. By flooding

d. By flooding

Determine the crest length of a structure for a chute spillway for a design flow of 1.4 cms and a maximum water level at the inlet is 0.5 m, the
coefficient of discharge is 1.66.
a. 0.54 m
b. 2.38 m
c. 4.38 m
d. 3.28 m

b. 2.38 m

q = CLH^(3/2)
q - discharge, cms
C - coefficient of discharge
L - length, m
H - depth of flow over the crest, m

Replanting of forest trees species in the watershed area
a. Cropping systems
b. Strip cropping
c. Agroforestry
d. Reforestation

d. Reforestation

A rectangular water tank, 2 m high is filled with water. Due to rust, a circular hole was made to the lowest portion of one side of the tank.
Considering that the tank is maintained full, what is the velocity of water right after its take off from the hole?
a. 6.26 m/s
b. 4.43 m/s
c. 39.22 m/s
d. 19.63 m/s

a. 6.26 m/s

The channel where diverted water from a source flows to the intended area to be irrigated
a. Headworks
b. Secondary canal
c. Main canal
d. National irrigation system

c. Main canal

The normal depth in a 2m wide concrete lined trapezoidal irrigation canal with a side slope z of 2 and a bottom slope of 0.2% for a discharge is 1.65m3/s is.
a. 0.6m b. 1.6m c. 2.6m d. 3.6m

a. 0.6m

From PAES 603:2016, concrete lined canal’s roughness coefficient is 0.013.

solved depth using that n is 0.4 m, closest answer is 0.6 m.

However, if n is 0.03 the calculated depth is 0.6 m.

The method of fertilizer application in which the fertilizer is dissolved in water as prescribed and then sprayed on the upper portion of the plant particularly the leaves:
a. broadcast method
b. side dressing method
c. foliar spray fertilizer
d. localized fertilizer

c. foliar spray fertilizer

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
b. air dry
c. Hygroscopic coefficient
d. field capacity

d. field capacity

Plants living more than one year but in some cases, producing seed in the first year and every season thereafter:
a. annual
b. quarter-annual
c. biennial
d. perennial

d. perennial

Vulnerability or susceptibility of the soil t o erosion. It is a function of both the physical properties of the soil and land management practices.
a. Erodibility
b. Erosivity
c. Susceptibility
d. Vulnerability

a. Erodibility

A horizontal fully flowing 4 in pipe isdischarging water. The x and y-coordinate of the water trajectory is measured from the end of the pipe are 1.5 m and 0.8 m, respectively. Assuming that the coefficient of discharge is 1.0, what is the discharge of the pipe?
a. 10 lps
b. 20 lps
c. 30 lps
d. 40 lps

c. 30 lps

Q(lps) = 0.0174d^2X/sqrt(Y)

d - cm
X - cm
Y - cm

It is the simplest piece of overhead irrigation equipment and is commonly used in small-scale upland farming.
a. Hose pipe
b. Watering can
c. Drainage
d. Overhead irrigation

b. Watering can

An imaginary line of constant elevation on the surface of the ground.
a. Horizontal interval
b. Vertical Interval
c. Contour map
d. Contour line

d. Contour line

What should be the minimum weir height for measuring a flow of 1000 gpm with a 90 degree V-notch weir, if the flow is now moving at 5 ft/sec in a 2 ft wide rectangular channel?
a. 1.5 ft
b. 1.3 ft
c. 1.4 ft
d. 1.2 ft

d. 1.2 ft

the given velocity is not a Velocity of Approach.
It is the velocity after leaving the weir. (Critical velocity)

Weir height is 1.2 to 1.5 times the head over the weir.

The peak runoff in an 80ha watershed corresponding to a rainfall intensity of 20mm/hr and a runoff coefficient of 0.7 is.
a. 3.1m3/s b. 4.1m3/s c. 5.1m3/s d. 6.1m3/s

a. 3.1m3/s

The process of covering the land surface with plant residues, plastic or other materials appropriate to arrest loss of moisture through evaporation
a. Cropping systems
b. Contour cultivation
c. Mulching
d. Strip cropping

c. Mulching

A 10 inch diameter pipe is flowing 1/3 full, what is the velocity of the water if the volume of flow is 135 gpm?
a. 7.2 m/s
b. 2.0 ft/sec
c. 10.6 ft/sec
d. 3 m/s

b. 2.0 ft/sec

1/3 full means 1/3 of the diameter

The ratio of the volume of water to the total soil volume
a. Soil Texture
b. Volume basis or volumetric MC
c. Porosity
d. dry weight basis

b. Volume basis or volumetric MC

The Scientific name for onion:
a. Raphanus sativus
b. Daucus carota
c. Allium sativum
d. Allium sepa

d. Allium sepa

On a 20% hill slope, it is proposed to construct bench terraces with 1:1 batter slope, if the vertical interval is 2 m, what is the width of the
terrace?
a. 10 m
b. 20 m
c. 8 m
d. 16 m

c. 8 m

For batter slope 1:1
VI = HD(S)/100-S

For batter slope 1/2:1
VI = 2HD(S)/200-S

HD - horizontal distance
S - slope in percent
VI - vertical interval

A major irrigation system managed by the national irrigation administration
a. Communal irrigation system
b. Secondary canal
c. Main canal
d. National irrigation system

d. National irrigation system

Evapotranspiration in an 8 ha farm is 7mm/day and percolation losses is 2 mm/day. What is the design discharge of a canal to be able to deliver a 5 day requirement of the farm in 24 hours, if irrigation efficiency is 75%?
a. 150 cu.m/hr
b. 200 cu.m/hr
c. 175 cu.m/hr
d. 140 cu.m/hr

b. 200 cu.m/hr

Required volume of water = (7+2)(5day)(8ha)(10000m2/ha)(1m/1000mm)/0.75
V = 4800 m3
Q = 4800/24hrs
Q = 200 cu.m/hr

Expresses the relationship between speed in rpm, discharge in gpm, and head in feet.
a. Static head
b. Specific speed
c. Drawdown
d. Characteristic curve

b. Specific speed

What is the depth of water in a trapezoidal channel with a sideslope of 2 and carrying a 2.5 cu.m/s water flow? The channel bottom width is 1.5 m and the flowing water has a velocity of 0.8 m/s.
a.1.00 m
b.0.93 m
c.1.20 m
d.0.82 m

b.0.93 m

Provides record of the highest stage observed at a stream
a. Float method
b. Float type water stage recorder
c. Bubbler gage
d. Crest stage gage

d. Crest stage gage

An association of farmers within a contiguous area served by a national irrigation system or communal irrigation system
a. Irrigators’ Association
b. Irrigation System
c. Irrigated Lands
d. Irrigable Lands

a. Irrigators’ Association

How many sprinklers with spacing of 7m x 7m are needed to irrigate a rectangular piece of land 125m x 190m if the laterals are set parallels to the longer side of the field.
a. 503
b. 504
c. 459
d. 485

27 sprinkler/lat x 17 laterals = 459 sprinklers
125/7 = 17.85
190/7 = 27.14

ALWAYS ROUND DOWN

Given the following direct runoff hydrograph in m3/s taken at 1hr interval in the mainstream of a 50sq.km watershed:0, 2.8, 13.8, 44.8, 77.8, 37.8, 12.8, 4.5, 1.8, 1.3, 0.9, 0.6, 0.2. The equivalent depth of direct runoff is.
a. 14.3mm b.15.3mm c.16.3mm d.17.3mm

a. 14.3mm

Total volume = (summation of direct runoff)(time interval)

Total volume = 716760 m3

Equivalent depth = 716760 m3/Area = 14.3 mm

The ratio between the water delivered to the farm and the water diverted from a river or reservoir expressed in percent
a.Water storage efficiency
b.Water-use efficiency
c.Water application efficiency
d.Water conveyance efficiency

d.Water conveyance efficiency

Consists of carrying out agricultural operations very nearly on the contour. It reduces the velocity of overland flow and retards soil erosion
a.Cropping systems
b.Contour cultivation
c.Mulching
d.Strip cropping

b.Contour cultivation

Is a graphical representation of the instantaneous runoff rate against time. The area under the hydrograph gives the runoff volume
a.Hydrograph
b.Pearson hydrograph
c.Log-Normal Distribution hydrograph
d.Normal hydrograph

a.Hydrograph

An irrigation system that is managed by a bonafide irrigators’ association
a. Headworks
b. Communal irrigation system
c. Shallow tubewell
d. National irrigation system

b. Communal irrigation system

Record the pressure required to maintain a small flow of gas from an orifice submerged in the stream
a. Float method
b. Float type water stage recorder
c. Bubbler gage
d. Crest stage gage

c. Bubbler gage

A soil sample was obtained using s cylindrical soil sampler with a 4 inches diameter and 10 inches height. After oven drying the sample weight 2470 g, what is the soil bulk density?
a. 12 g/cc
b. 11 g/cc
c. 1200 kg/cu.m
d. 1.3 kg/cu.m

c. 1200 kg/cu.m

A dam spillway is to be designed to have a service life of 50 years. If the acceptable risk for structural failure due to excessive flood discharge is 10%, the spillway should be designed for a return period of.
a. 175 years
b. 275 years
c. 375 years
d. 475 years

d. 475 years

P=1 - (1 - 1/T)^n
P = acceptable risk of failure (10% or 0.10),
T = return period (in years, which we’re solving for),
n = service life of the structure (50 years).

Planting different crops simultaneously in the same field at the same cropping season.
a. Graded terrace
b. Relay cropping
c. Multi cropping or mixed cropping
d. Strip cropping

c. Multi cropping or mixed cropping

An irrigation engineer is to irrigate a crop planted in furrows of 100m x 100m area. The inflow rate is 0.5 li/sec/100m. If the furrow spacing is 50 cm and the application depth is 100 mm, determine the time in hours to irrigate the whole area.
a. 55.68 hrs
b. 555.6 hrs
c. 450.17 hrs
d. 245.56 hrs

b. 555.6 hrs

Discharge is not constant with respect to time
a. Spatially variable flow
b. Turbulent flow
c. Laminar flow
d. Unsteady flow

d. Unsteady flow

The lateral flow of liquid through porous media; the lost of water from irrigation canals.
a. Soil conservation
b. Seepage
c. Percolation
d. Watershed

b. Seepage

Find the irrigation interval. Given the ff. WHC- 1.5; MAD- 50%; allowed depletion-0.75 cm; ET/Ea-2.22 mm/day
a. 3 days
b. 2 days
c. 4 days
d. All of the above

a. 3 days

The discharge in a 6.56ft wide trapezoidal open channel with a side slope of 1:1 and a bottom slope of 0.1% is 98.8 ft3/s when the depth of flow is 1.0m. The roughness coefficient is.
a. 0.025 b.1.025 c.2.025 d.3.025

a. 0.025

A term adapted to measures utilizing both or in combination with the biological and engineering measures.
a. Culvert
b. Vengineering
c. Drop structures
d. Flume

b. Vengineering

Establishment of natural waterways or construction of canals and planting it with grasses to make it stable and arrest soil erosion
a. Riprap
b. Grassed waterways
c. Check dams or weirs
d. Farm Ponds / Water Impounding Dams

b. Grassed waterways

Landslides and slips due to saturation of steep hills and slopes.
a.Slip erosions
b.Wind erosions
c.Coastal erosions
d.Stream bank erosion

a.Slip erosions

A floating object travelled a distance of 10m in 9.5 seconds on the average in a 0.5m deep parabolic channel. If the top width is 1.0m the
discharge is.
a. 10.3m3/s
b. 1.3m3/s
c. 0.3m3/s
d. 5.3m3/s

c. 0.3m3/s

Q=VA
Area of parabola = 2/3bh
Q = (10m/9.5s)(2/3)(0.5 m)(1m) = 0.35 m3/s

The peak runoff in the mainstream of a watershed has a mean of 128 m3/s and a standard deviation of 52 m3/s. If the sample data is normally distributed, the magnitude of runoff corresponding to a probability of
exceedance of 16% is
a. 128 m3/s b. 76 m3/s c. 180 m3/s d. 52 m3/s

c. 180 m3/s

The scientific name for sheep:
a. Capra hircus
b. Sus domesticus
c. Bubalus Bubalis
d. Ovis aries

d. Ovis aries

Moisture content present in the soil when gravitational water has been removed is called:
a. wilting point b. field capacity
c. unavailable moisture d. nota

b. field capacity

A culvert has been designed for a flood discharge with a return period of 50 years. The risk that the culvert will experience the design flood one or more times in 75 years is
a. 2%
b. 22%
c. 67%
d. 78%

d. 78%

R=1-(1-P)^n
R is the risk (probability of at least one event occurring)
P is the annual probability of the event (flood) occurring, which is (P=1/T)
T is the return period (50 years)
n is the number of years (75 years)

The following infiltration capacity equation has been derived based on experimental data: f = 10 + 5e-12t where f is in mm/hr and t is in hr. The cumulative infiltration in mm after 45 minutes is
a. 7.5mm b. 7.9 mm c. 79 mm d. 450 mm

b. 7.9 mm

The water right based on the concept first time, first in right:
a. Right of way b. Appropriation Act
c. General Appropriation d. nota

b. Appropriation Act

The volume of water that can be stored in or released from an aquifer per unit horizontal area per unit change in hydraulic head is
a. specific storage
b. specific yield
c. storage coefficient
d. transmissivity

c. storage coefficient

The lateral movement of water in the soil:
a. seepage
b. drainage
c. irrigation
d. flooding

a. seepage

The velocities at depths of 0.16m and 0.64m in a 0.8m deep and 1.0m wide rectangular open channel are 1.2m/s and 0.3m/s, respectively. The discharge is.
a. 0.6m3/s
b. 1.6m3/s
c. 2.6m3/s
d. 3.6m3/s

Vave =(1.2 + 0.3)/2 = 0.75 m/s
Q=VA
Q = (0.75)(0.8)(1) = 0.6 m3/s

The discharge through a 90 v-notch weir may be computed by:
a. Q = 0.0184LH^3/2 b. Q = 0.0184(L-.2H)3/2
c. Q = 0.0186LH^3/2 d. Q = 0.0138H^5/2

d. Q = 0.0138H^5/2

A fully penetrating well installed in a confined aquifer with a transmissivity of 197 m2/day is pumped at a constant rate. If the drawdowns
in two observation wells 8 m and 22 m from the pumped well were observed to be 1.42 m and 0.44 m, respectively, the steady state pump discharge is
a. 200 gpm b. 220 gpm c. 240 gpm d. 260 gpm

b. 220 gpm

Confined aquifer
Q = 2piT(h2-h1)/ln(r2/r1)

Development of deep well by compressed air is best suited for ___wells.
a. big
b. small
c. open
d. nota

b. small

The velocities at 0.2 and 0.8 of the depth of flow in a parabolic open channel are 1.0 m/s and 0. 2 m/s, respectively. If the flow depth is 0.5 m and the top width is 1.5 m, the discharge is
a. 500 lps b. 450 lps c. 300 lps d. 250 lps

c. 300 lps

Q=VA
Area of parabola = 2/3bh
V = (v1+ v2)/2

The mass per unit volume of the soil particles is:
a. specific gravity b. porosity
c. soil density d. void ratio

c. soil density

The ratio of the volume of pores to the volume of solid is:
a. void ratio
b. porosity
c. specific gravity
d. soil density

a. void ratio - ratio of pores to the volume of solids
b. porosity - ratio of pores to the total volume

Water held by forces of surface tension and continuous films around the soil particles is:
a. capillary water
b. hygroscopic water
c. gravitational water
d. soil water

a. capillary water

Water held tightly to the surface of soil particle by adsorption
forces is:
a. capillary water
b. hygroscopic water
c. soil water
d. gravitational water

b. hygroscopic water

The peak runoff in a 50 ha-watershed corresponding to a rainfall intensity of 25 mm/hr and a runoff coefficient of 0.8 is
a. 2.8 m3/s
b. 28 m3/s
c. 280 m3/s
d. 1,000 m3/s

a. 2.8 m3/s

It is the sheet of water which overflows a weir:
a. Napped
b. weir pond
c. weir crest
c. weir gauge

a. Napped

Sprinkler type with operating pressure from 20-40 psi:
a. high pressure
b. low pressure
c. medium pressure
d. nota

b. low pressure

The type of erosion that takes place in small channels which cannot be obliterated by tillage operations is called
a. sheet
b. rill
c. interrill
d. gully

d. gully

An appurtenance to the pipeline which permits the passage of air to or
from the pipeline.
a. surge
b. water hammer
c. vent
d. gate

c. vent

It is the combined process of evaporation and transpiration from plants.
a. evaporation
b. transpiration
c. evapo-transpiration
d. condensation

c. evapo-transpiration

Barrier constructed to hold water back and raise its level.
a. channel
b. dam
c. well
d. weir

b. dam

The volume of water flowing each second, measured in m3/sec.
a. stream
b. discharge
c. velocity
d. cross-sectional area

b. discharge

Term for solar radiation received at the earth’s surface
a.insolation
b.illuminance
c.radiation
d.reflectiion

a.insolation

The channel connected to the main canal which distributes irrigation to specific areas
a. Headworks
b. Communal irrigation system
c. Shallow tubewell
d. Secondary canal

d. Secondary canal

The minimum distance from the center of the lone pumped well wherein no drawdown will be observed is the __________________.
a. well radius
b. radius of interference
c. radius of influence
d. drawdown curve

c. radius of influence

A 27 mm/day water requirement is equivalent to
a. 29.75 gpm/ha
b. 1.125 lps/ha
c. 3.125 lps/ha
d. 17.875 gpm/ha

c. 3.125 lps/ha

On the weather map, lines representing points of equal pressure is called.
a.Isohyets
b.Contour lines
c.Isobars
d.None of the above

c.Isobars

Planting different crops simultaneously in the same field at the same cropping season.
a. Mixed/multiple cropping
b. Relay cropping
c. Inter cropping
d. Strip cropping

a. Mixed/multiple cropping

Compute the unidirectional flow in two parallel drains; 1200 m apart if the soil hydraulic conductivity is 10m/day and the water level at the drains are 7 and 9 meters.
a. 0.00035 m2/hr c. 0.0083 m2/hr
b. 0.0007 m2/hr d. 0.0056 m2/hr

b. 0.0007 m2/hr

q=k(h2²-h1²)/2L

Compute the land soaking requirement for a soil (depth of rootzone = 35cm) with residual moisture content of 15% by mass, bulk density of 1,280 kg/m3 and porosity of 45%. Standing water for planting is 25 mm.
a. 115.3 mm
b. 134.4 mm
c. 90.3 mm
d. 159.4 mm

c. 90.3 mm

A 25-ft thick confined aquifer with hydraulic conductivity of 500ft/day was tapped by a 4”ϕ shallow tubewell. With a radius of influence of 2000 ft, determine the maximum discharge of the STW in liters per second. Assume an
allowable drawdown of 10 ft.
a. 29.61
b. 27.43
c. 41.15
d. 44.42

a. 29.61 lps

Q=2pikt(hw)/ln(re/r)

For an 8m x 8m sprinkler spacing, what is the design sprinkler throw for a 40% overlap?
a. 3.2 m
b. 6.4 m
c. 5.6 m
d. 10 m

c. 5.6 m

An unconfined aquifer is situated above a horizontal impervious base and is composed of sand with a hydraulic conductivity of 12m/day. In this aquifer, two fully penetrating ditches from a strip of land with a constant width of 1250m. The water level in the left and right ditches rises to 8 and 12m above the impervious base, respectively. The recharge by rainfall is 7.5 mm/day. Evaporation losses amount to 2.5 mm/day.
-Compute the flow into the right drain.
a. 3.509 m2 / day c. 2.741 m2 / day
b. 5.0715 m2 / day d.4.3035 m2 / day
-Compute the flow into the left drain.
a. 3.509 m2 / day c. 2.741 m2 / day
b. 5.0715 m2 / day d.4.3035 m2 / day
-Compute the maximum elevation of water table inside the strip of land.
a. 18.53 m
b. 16.41 m
c. 16.11 m
d. 18.70 m

c. 2.741 m2 / day
a. 3.509 m2 / day
b. 16.41 m

qR=RL/2 + k(h1²-h2²)/2L
qL=RL/2 +k(h2²-h1²)/2L
xs=L/2 +k(h2²-h1²)/2RL (from left drain)
hmax = sqrt((Rxs/k)(L-xs) + (xs/L)(h2²-h1²) + h1²)

R - net recharge
L - drain spacing
xs - stagnation point
k - hydraulic conductivity
h - height of water in the drain
hmax - max water table height (usually at stagnation point)

The 60 cm deep rootzone of a soil has volumetric field capacity and wilting point of 0.345 and 0.236 respectively. Crop consumptive use is 7.2 mm/day. Compute for the irrigation interval assuming there is 1.7 mm
daily rainfall and 80% allowable moisture depletion.
a. 8 days
b. 9 days
c. 10 days
c. 10 days

b. 9 days

For the most efficient trapezoidal cross-section:
a. width of the bottom=1.5 of the depth
b. width of the top=sum of sides
c. width of the bottom=twice the depth
d. width of the top=1/2 the sum of sides

b. width of the top=sum of sides

A conveyance structure used to turn conduits of varying sizes and shapes.
a. cut off
b. transition
c. weir
d. chute

b. transition

Surface irrigation method where a much smaller area is enclosed by levees.
a. trickle irrigation
b. drip irrigation
c. basin flooding
d. flood routing

c. basin flooding

The critical depth in a rectangular channel with a bottom width of 4.0 m for a discharge of 5 m3/s is
a. 0.34 m b. 0.44 m c. 0.54 m d. 0.64 m

c. 0.54 m

dc = cbrt(Q^2/b^2 g)

That part of surface runoff that flows over the surface towards the stream channel
a.Base flow
b.Direct runoff
c.Overland flow
d.Peak flow

c.Overland flow

Erosion of stream banks by flowing water.
a.Slip erosions
b.Wind erosions
c.Coastal erosions
d.Stream bank erosion

d.Stream bank erosion

A 30-inch diameter 1-meter long culvert has been designed to carry a maximum discharge of 1.7 m3/s when flowing half-full. Its roughness coefficient n is 0.014. If the inlet and the outlet are both unsubmerged, the difference in elevation between the inlet and the outlet should be
a. 5 cm b. 7.5 cm c. 10 cm d. 12.5 cm

c. 10 cm

What is the depth of water in a trapezoidal channel with a sideslope of 2 and carrying a 2.5 m3/s water flow? The channel’s bottom width is 1.5 meters and the flowing water has a velocity of 0.8 m/s.
a. 0.93m
b. 1.93m
c. 2.93m
d. 3.93m

a. 0.93m

A vertical section to the soil mass where significant changes in the soil texture and structure with depth are observed
a.Soil profile
b.Soil structure
c.Soil texture
d.Soil taxonomy

a.Soil profile

The moisture content of the soil when tension is 1/3 atmosphere.
a.Field capacity
b.Saturation point
c.Wilting point
d.None of the above

a.Field capacity

This refer to the additional height or depth of hydraulic structures
a. Flash board
b. Free board
c. Jump height
d. Critical depth

b. Free board

The rational method of determining runoff is applicable to.
a.Small watershed
b.Large watershed
c.Watershed with good vegetation
d.All watershed

c.Watershed with good vegetation

Refers to the number of days between irrigation periods without rainfall.
a. irrigation frequency
b. irrigation efficiency
c. Irrigation method
d. irrigation period

a. irrigation frequency

It is type of erosion where small channels are formed on the surface of the soil
a.Splash
b.rill
c.sheet
d.gully

b.rill

One in which a definite law of certainty exists
a.Stochastic process
b.Probabilistic process
c.Deterministic process
d.Barrow process

c.Deterministic process

The other term for gravity well.
a. Confined well
b. Water table well
c. Deep well
d. Well on perched aquifer

c. Deep well

A storm type occuring at the boundaries of warm moist air and dry cold air.
a.Orographic storm
b.Frontal storm
c.Convective storm
d.None of the above

b.Frontal storm

The no. of days allowed for operating irrigation to a given design area during the peak consumptive period of the crop being irrigated.
a. irrigation method
b. irrigation period
c. irrigation frequency
d. irrigation efficiency

b. irrigation period

A concrete-lined trapezoidal canal is to carry a maximum discharge of 2.0 m3/s. The required head loss over a horizontal distance of 1 km is 2.0 m. The side slope is to be set at 1:1 and the permissible b/d ratio is 3. If the Manning’s roughness coefficient is 0.015, the design depth required is
a. 0.42 m
b. 0.56 m
c. 0.64 m
d. 0.78 m

b. 0.56 m

A property associated with surface tension of liquid and manifested in the rise and fall of liquids in small diameter tubes.
a. conduction
b. capillary
c. cavitation
d. condensation

b. capillary

Amount of rainfall in the rootzone.
a. consumptive use
b. seepage
c. percolation
d. effective rainfall

d. effective rainfall

The most hydraulically efficient trapezoidal channel section to carry a discharge of 5 m3/s on a bed material with a roughness n of 0.02 and a bottom slope of 1 in 800 should have a bottom width of
a. 0.75 m
b. 1.35 m
c. 1.65 m
d. 2.25 m

c. 1.65 m

b = 2dtan(θ/2)

The soil has a field capacity of 22% and a permanent wilting point of 12 %, both on a dry mass basis. The apparent specific gravity is 1.4. If the rootzone depth is 1.0 m and the management allowable deficit is 50%, the net
application depth is
a. 50 mm
b. 60 mm
c. 70 mm
d. 80 mm

c. 70 mm

A 3-ha of cornfield is to be irrigated at a discharge of 250 lps. The average available water holding capacity is 140 mm/m soil, the management allowable deficit is 40%, and the rootzone depth is 0.5 m. The reference crop
potential evapotranspiration is 5 mm/day and the crop coefficient is 0.8. Assuming 70% application efficiency, the irrigation period should be
a. 1 hr
b. 1 ¼ hrs
c. 1 1/3 hrs
d. 1 ½ hrs

c. 1 1/3 hrs

A notch of regular form through which the irrigation stream is made to flow and flow built as either portable or stationary structures is called:
a. orifice
b. parshall flume
c. weir
d. dam

c. weir

For the most efficient circular cross-section, semi-circle the hydraulic radius is equal to:
a. ¼ its radius
b. its radius
c. ½ its radius
d. ¼ its diameter

d. ¼ its diameter

The amount of water used in producing crop is:
a. water holding capacity
b. critical growth stage
c. rooting characteristics
d. percolation

a. water holding capacity

Water that moves freely and drains out of the soil is:
a. gravitational
b. capillary
c. S.I.A.
d. hygroscopic

a. gravitational

How much water should be applied to a 6 ha farm where the rooting depth is 80 cm if it is in its permanent wilting point? Volumetric moisture contents are 0.15 and 0.32 for permanent wilting point and field capacity,
respectively.
a. 1,160m3
b. 4,160m3
c. 6,160m3
d. 8,160m3

d. 8,160m3

Sugarcane is to be irrigated using sprinkler irrigation. The sprinkler spacing is 12.2 m while the lateral spacing is 18.3 m. The soil water holding capacity is 120 mm/m, crop rooting depth is 1.0 m and management allowable
deficit is 45%. If the irrigation period is 12 hrs and the application efficiency is 70%, the required sprinkler discharge is
a. 0.2 lps
b. 0.3 lps
c. 0.4 lps
d. 0.5 lps

c. 0.4 lps

In drainage, open channel is often referred to as:
a. canals
b. traps
c. manholes
d. drains

a. canals

The direct attraction of similar molecules between similar molecules.
a. collision
b. attraction
c. repulsion
d. cohesion

d. cohesion

Groundwater is to be pumped from a shallow aquifer for irrigation purposes. The required discharge is 300 gpm. The suction head is 8 ft and the maximum drawdown is 10 ft. The friction and minor losses are 0.45 ft and 0.3
ft, respectively. If the pump efficiency is 60%, the theoretical input power required is
a. 2.0 hp
b. 2.2 hp
c. 2.4 hp
d. 3.0 hp

c. 2.4 hp

A temporary method of drainage artificially produced in the subsoil with digging a trench from the surface.
a. canal
b. flood routing
c. transition
d. mole drain

d. mole drain

The depth of water in mm or inches to be removed in 24 hr period from the drainage area.
a. infiltration rate
b. drainage coefficient
c. infiltration
d. percolation

b. drainage coefficient

Other terms for drip irrigation are __________ irrigation and __________ irrigation. This type of overhead irrigation operates at low pressure.
a. trickle – micro
b. sprinkle – slide
c. trickle – border
d. corrugation – trickle

a. trickle – micro

It is the average interval of time within the magnitude of given event will be equaled or exceeded at least once on the average.
a. period of exceedence
b. hydrologic frequency
c. return period
d. all of the above

c. return period

Ratio of the bulk density to the density of water.
a. oven-dry weight
b. apparent specific gravity
c. soil volume
d. porosity

b. apparent specific gravity

In open channel, the term A/P is:
a. hydraulic gradient
b. hydraulic radius
c. hydraulic conductivity
d. hydraulics

b. hydraulic radius

These are usually rural traders or barrio buyers who do accumulation of the produce of individual farmers and bulk these for storage or for distribution to wholesalers
a. assemblers
b. wholesalers
c. retailers
d. agents and brokers

a. assemblers

It is used to divide and distribute the flow of water at desired direction usually placed or built in main farm ditch to divert water to supplementary farm ditches.
a.spill wall
b.turnout
c.flume
d.division box

d.division box

In designing an open channel, it is necessary to know what the material firming the channel bed is to know the value of:
a. roughness coefficient
b. side slope
c. bed slope
d. bottom slope

a. roughness coefficient

This refers to wants for specific satisfiers backed up by an ability and willingness to buy them.
a. need
b. want
c. demand
d. value

c. demand

An irrigation method formed by building longitudinal levees approximately parallel to the contour and connecting them at a desirable places with levees at right angle.
a. check contour
b. border
c. basin
d. furrow

a. check contour

A device used to control the flow of water to or from a pipeline.
a. Inlet
b. gate
c. weir
d. flume

b. gate

Determine the head loss in a 4” aluminum lateral 500 ft long if sprinkler spacing is 50 ft. Sprinkler discharge is 0.25 lps.
a. 2.72ft
b.3.72ft
c.4.72ft
d.5.72ft

a. 2.72ft

Use Scobey’s equation

Hf =(ksLQ^(1.9))/D^(4.9) x (4.1 x 10^6)

ks = pipe coefficient (0.32 PVC, 0.40 Al, 0.42 GI)

A closed conduit usually circular, square or rectangular in cross section, used for conveying water across and under an elevated roadway,
embankment and dikes.
a. gate
b.culvert
c.canal
d.drop

b.culvert

This is a marketing function which facilitates transfer of ownership
a. assembly
b. storage
c. negotiation
d. grading

c. negotiation

It also refers to consumptive use by crops.
a. evapotranspiration
b. water circulation
c. saturation vapor pressure
d. osmosis

a. evapotranspiration

It is natural or artificial channel that shortens a meandering stream.
a. cut off
c. chutes
b. drawdown
d. transition

a. cut off

A concept used to evaluate the losses of water during irrigation from the time it leaves that source to the point of use.
a. irrigation efficiency
b. drainage efficiency
c. Discharge flow rate
d. nota

a. irrigation efficiency

This is oftentimes not considered a marketing activity, but it is a marketing function. This is because agricultural products must pass through some levels of transformation before being made available to the users. This marketing function increases marketability of products by changing product forms.
a. packaging/packing
b. grading
c. storage
d. processing

d. processing

The most simple form of open channel flow computation is:
a. unsteady uniform flow
b. steady non-uniform flow
c. steady uniform
d. unsteady non-uniform

c. steady uniform

These are intermediaries who deal directly with the end-users or the consumers. They are the wholesalers’ partners in distribution activities.
a. agents
b. retailers
c. assemblers
d. brokers

b. retailers

The speed at which water flows in channel is:
a. velocity
b. discharge
c. runoff
d. volumetric flow

a. velocity

It is equal to the cross-sectional area times the velocity of flow.
a. velocity
b. discharge
c. evaporation
d. runoff

b. discharge

Water that moves freely and drains out of the soil is:
a. hygroscopic water
b. capillary water
c. gravitational water
d. sea water

c. gravitational water

It is the state of felt deprivation of some basic satisfaction
a. need
b. want
c. demand
d. exchange

a. need

It is the most elaborate method of computing potential evapotranspiration:

a. Blaney-Criddle
b. Jensen-Haise
c. Hargreaves
d. Penman

d. Penman

Methods of supplying water in the basin
a. direct supply and cascade supply
b. flooding and pumping
c. sprinkling and dripping
d. wild flooding and pressurized supply

a. direct supply and cascade supply

It is anything offered for sale, attention, and acquisition
a. prospect
b. target market
c. product
d. market segment

c. product

Which is not part of the macro-environment?
a. demographic
b. suppliers of raw materials
c. technological
d. politico-legal

b. suppliers of raw materials

Groundwater is to be pumped from a shallow aquifer for irrigation purposes. The required discharge is 300 gpm. The suction head is 8 ft and the maximum drawdown is 10 ft. The friction and minor losses are 0.45 ft and 0.3 ft, respectively. If the pump efficiency is 60%, the theoretical input power required is.
a. 5.4Hp
b. 4.4 Hp
c. 3.4 Hp
d. 2.4 Hp

d. 2.4 Hp

P(Hp) = QH/3960Eff

Q = 300 gpm
H = 10 + 8 + 0.45 + 0.3
Eff = 0.6

Same as interflow
a. Surface runoff
b. Subsurface runoff
c. Groundwater runoff
d. Runoff volume

b. Subsurface runoff

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

a. aquifuge

Compute the land soaking requirement for a soil ( depth of rootzone = 60cm) with residual moisture content of 18 % by weight, bulk density of 1,320 kg/m3 and porosity of 50%. Standing water for planting is 20 mm.
a. 177.44 mm
b. 157.44 mm
c. 253.44 mm
d. 273.44 mm

b. 157.44 mm

LSR = (n - (RMCxAs))DRZ

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

What is the rootzone depth of a farm with land soaking requirement of 90mm if the soil porosity is 45%, residual moisture content is 18% (by weight) and bulk density is 1,250kg/m3?

a. 35cm c. 40cm
b. 45cm d. 60cm

c. 40cm

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 c. equal to
b. greater than d. not related to

a. less than

For an 10 m x10m sprinkler spacing, what is the design sprinkler throw for a 50% overlap?

a. 15 m c. 8 m
b. 7.5 m d. 5 m

b. 7.5 m

Four liters per second is equal to

a. 14.4 m3/hr
b. 63.41 gpm
c. both a and b
d. neither a nor b

c. both a and b

Irrigation method 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

What is the design discharge of a canal to be able to deliver a 6-day requirement of a 6-ha farm in 9 hours if the irrigation requirement is 8mm/day?

a. 88.9 m3/s c. 0.889 m3/s
b. 8.89 m3/s d. 0.0889 m3/s

d. 0.0889 m3/s

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 w/ the rainfall or irrigation water.
b. The drains are evenly spaced.
c. Darcy’s law is valid for flow through the soils.
d. All of the above.

d. All of the above.

______ is 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 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 moisture
c. permanent wilting point
d. saturation point

a. field capacity

The infiltration equation based on the exhaustion process is the _____.
a. Lewis-Kostiakov’s
b. Horton’s
c. Philip’s
d. Darcy’s

b. Horton’s

Run-off is the difference between the gross depth of irrigation water and the____.
a. net depth requirement
b. depth that infiltrated
c. crop evapotranspiration
d. water use rate

b. depth that infiltrated

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

In a drip system, the allowable pressure variation in a lateral with minimum and average head of 1.51 and 1.38 mters respectively is _____.
a. 0.185 psi
b. 0.462 psi
c. 0.370 psi
d. 0.130 psi

b. 0.462 psi

Allowable pressure = 2.5(ΔH)
AP = 2.5 (1.51 - 1.38) m x (1.42 PSI/1 m)
AP = 0.462 PSI

The head in an emitter discharging 4 liters of water per hour and with discharge coefficient of 0.798 and exponent of 0.5 is___.
a. 6.4 m
b. 5 m
c. 10 m
d. 1.8 m

PAES 608:2016 8.7.2
q (L/h) = KdH^x
Kd = discharge coefficient
H = head, m
x = exponent

Computer aided method wherein it averages estimated precipitation at all points of a superimposed grid.
a. Inverse Distance Ratio Method
b. Grid-Point Method
c. Isohyetal
d. Thiessen polygon

b. Grid-Point Method

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

Distribution control structures placed across an irrigation ditch to block the flow temporarily and to raise the upstream water level.

a. turnouts c. culverts
b. checks d. weirs

b. checks

Using Scobey’s equation for friction loss, a lateral with 10 sprinklers has a reduction coefficient of ____.
a. 0.3766
b. 0.100
c. 0.200
d. 0.3964

d. 0.3964

Which is not a component of the impact arm of an impact sprinkler?
a. nozzle
b. counterweight
c. vane
d. spoon

a. nozzle

A 20-ft thick confined aquifer with hydraulic conductivity of 400ft/day was tapped by a 4” Φ shallow tubewell. With a radius of influence of 2500 ft, determine the maximum discharge of the STW in liters per second. Assume an
allowable drawdown of 12 ft.
a. 22.17
b. 20.57
c. 62.71
d. 25.63

a. 22.17

Q = 2piT(h2-h1)/ln(r2/r1)

Used when there is skewness in the data distribution
a. Gamma Density Function
b. Pearson Type III Distribution
c. Log-Normal Distribution
d. Normal Distribution

c. Log-Normal Distribution

Governed by chance; time series INDEPENDENT
a. Stochastic process
b. Probabilistic process
c. Deterministic process
d. Barrow process

b. Probabilistic process

Station locations and amounts of rainfall are plotted on a suitable map, and contours of equal precipitation (isohyets) are then drawn.
a. Inverse Distance Ratio Method
b. Grid-Point Method
c. Isohyetal
d. Thiessen polygon

c. Isohyetal

This method can be used if there is a piped water-distribution system where a hose pipe can be connected to a tap or outlet and there is enough pressure in the water as it emerges from the hose pipe
a. Hose pipe
b. Watering can
c. Drainage
d. Overhead irrigation

a. Hose pipe

In surface irrigation, the ratio between the gross amount of irrigation water and the net requirement of the crop is the _____

a. application efficiency

It is an orderly sequence of planting crop in an area for a 365-day period.

a. cropping pattern c. crop sequence
b. crop combination d.cropping schedule

a. cropping pattern

A 21.6mm/day water requirement is equivalent to

a. 23.8 gpm/ha
b. 0.9 lps/ha
c. 2.5 lps/ha
d. 14.3 gpm/ha

c. 2.5 lps/ha

In the furrow irrigation, it is the difference between the depth of water that infiltrated and the net depth requirement is the

a. runoff
b. application losses
c. deep percolation
d. seepage

c. deep percolation

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Soil & Water Resources Development and Conservation, Irrigation, Drainage and Allied Subjects (HIGH PRIO) Flashcards

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