SWCE Flashcards by Rai Olino

What is the probability of occurrence of a 500-year hydrologic event?
A. 5% C. 0.02%
B. 0.002% D. 0.2%

D. 0.2%

How well did you know this?

Not at all

Perfectly

Determine the discharge on a free discharging circular orifice (4” diameter)
installed at the end of a rectangular channel that is 40 cm wide. The total height
of water flowing in the channel is 50 cm. The orifice centerline is 30 cm from the
channel bottom. Discharge coefficient is 0.65.
A. 257.47 L/s C. 12.78 L/s
B. 10.44 L/s D. 16.50 L/s

B. 10.44 L/s

How well did you know this?

Not at all

Perfectly

: A 4” diameter well abstracts water from a confined aquifer. The steady
state drawdown at distances of 10m and 60m are respectively 2.4 m and 0.5 m.
The thickness of the aquifer and hydraulic conductivity are given as 15m and
10m/day respectively.
35. The aquifer transmissibility is __________________.
A. 600 m2/day C. 1.2 m2/day
B. 150 m2/day D. 54 m2/day

B. 150 m2/day

How well did you know this?

Not at all

Perfectly

: In a stream with a cross-sectional area of 15.2 m2, the trial runs for a
buoyant object to travel a water surface distance of 80 m were 52, 54, 53, 55 and
58 seconds each.
37. The average surface velocity is _________.
A. 0.98 m/s C. 0.68 m/s
B. 1.47 m/s D. 0.88 m/s

B. 1.47 m/s

How well did you know this?

Not at all

Perfectly

: In a stream with a cross-sectional area of 15.2 m2, the trial runs for a
buoyant object to travel a water surface distance of 80 m were 52, 54, 53, 55 and
58 seconds each.
38. The apparent flow rate in the given stream is _______.
A. 10.34 m3/s C. 18.99 m3/s
B. 22.34 m3/s D. 11.41 m3/

C. 18.99 m3/s

How well did you know this?

Not at all

Perfectly

Given the following direct runoff (m3/s) from a hydrograph taken at 1-
hour interval in the mainstream of a 50 km2 watershed: 0.0, 13.8, 44.8, 77.8, 37.8,
12.8, 4.5, 1.8, 1.3, 0.9, 0.6, 0.2, determine the equivalent depth of direct runoff
A. 14.0 mm
B. 16.0 mm
C. 3.93 mm
D. 12.0 mm

A. 14.0 mm

How well did you know this?

Not at all

Perfectly

What is the equivalent depth of the direct runoff that fell on a 576-hectare
watershed if the sum of the direct runoff values measured in the reference stream
every two hours is 200m3/s?
A. 25 mm C. 250 mmB. 50 mm D. 500 mm

C. 250 mm

How well did you know this?

Not at all

Perfectly

A small water impoundment is designed for a 25-year flood with a peak
flow of 5 m3/s. Determine the probability of exceedance in a period of 10 years.
A. 4%
B. 10%
C. 33%
D. 93%

C. 33%

How well did you know this?

Not at all

Perfectly

The role of hydrologist for water control is related
A. water withdrawal
B. instream uses
C. point and non-point sources
D. flood and drought mitigation

D. flood and drought mitigation

How well did you know this?

Not at all

Perfectly

A color code of red means that the rain to be expected in the next hour is ____________. A. below 7.5 mm
B. 7.5 – 15 mm
C. 15 – 30 mm
D. above 30 mm

D. above 30 mm

How well did you know this?

Not at all

Perfectly

This is a type of precipitation caused by hills or mountain ranges deflecting
the moisture-laden air masses upward, causing them to cool and precipitate their
moisture.
A. Convective Precipitation
B. Frontal Precipitation
C. Orographic Precipitation
D. Cyclonic Precipitation

C. Orographic Precipitation

How well did you know this?

Not at all

Perfectly

The type of precipitation associated with the highest amount of rainfall
contribution in the Philippines.
A. Convective Precipitation
B. Frontal Precipitation
C. Orographic Precipitation
D. Cyclonic Precipitation

D. Cyclonic Precipitation

How well did you know this?

Not at all

Perfectly

This affects mainly the climate distribution of the Luzon Island.
A. Frontal Precipitation
B. Orographic Precipitation
C. Convective Precipitation
D. Cyclonic Precipitation

B. Orographic Precipitation

How well did you know this?

Not at all

Perfectly

Which among the following has the longest wavelength?
A. infrared
B. untraviolet
C. gamma
D. visible light

A. infrared

How well did you know this?

Not at all

Perfectly

The WMO recommends a minimum network density for mountainous
tropical zones of
A. 1 gauge for 100 to 250 km2
B. 1 gauge for 600 to 900 km2
C. 1 gauge for 900 to 3000 km2
D. 1 gauge for 1500 to 10,000 km2

A. 1 gauge for 100 to 250 km2

How well did you know this?

Not at all

Perfectly

Which among the following is false?
A. New Thiessen polygons must be constructed when a new station is
installed.
B. Cyclones in the northern hemisphere moves in the counterclockwise
direction.
C. Greater evaporation occurs on areas with high albedo.
D. The intensity of a storm is an inverse function of its duration

C. Greater evaporation occurs on areas with high albedo.

How well did you know this?

Not at all

Perfectly

Equal values of dry bulb temperature and wet bulb temperature would
yield a relative humidity of
A. a positive value
B. a negative value
C. 0 %
D. 100 %

D. 100 %

How well did you know this?

Not at all

Perfectly

The decrease in temperature with respect to an increasing altitude can be
manifested on what layers?
A. troposphere and mesosphere
B. tropopause and stratopause
C. mesosphere and chromosphere
D. stratosphere and ozone layer

A. troposphere and mesosphere

How well did you know this?

Not at all

Perfectly

Winter solstice in the southern hemisphere occurs some time inA. March
B. June
C. September
D. December

B. June

How well did you know this?

Not at all

Perfectly

Perihelion in the northern hemisphere occurs some time in
A. January
B. March
C. July
D. December

A. January

How well did you know this?

Not at all

Perfectly

Which of the following is not a precursor in cyclogenesis or the formation
of a cyclone?
A. pre-existing atmospheric disturbance
B. strong vertical wind shear
C. a close location relative to the equator
D. a low relative humidity in the troposphere

B. strong vertical wind shear

How well did you know this?

Not at all

Perfectly

The globalized atmospheric circulation is brought about by the following
factors except the
A. inclination of the earth
B. Coriolis effect
C. uneven solar heating at different latitudes
D. location of the earth relative to the sun

D. location of the earth relative to the sun

How well did you know this?

Not at all

Perfectly

The instrument that can measure the amount of solar radiation using a
copper strip
A. Campbell-Stokes Sunshine recorder
B. pyranograph
C. bi-metallic actinograph
D. Gunn-Bellani pyranometer

C. bi-metallic actinograph

How well did you know this?

Not at all

Perfectly

The instrument used to measure the water level in the evaporation pan.
A. hook gauge
B. dumb-bell index
C. stilling well
D. anemometer

A. hook gauge

How well did you know this?

Not at all

Perfectly

7. How do you classify a cyclone with maximum sustained winds of 100 kph?A. typhoon B. super typhoon C. severe tropical storm D. tropical storm

C. severe tropical storm

About how many percent of the incoming solar radiation is absorbed by the earth’s atmosphere? A. 6 B. 16 C. 20 D. 50

C. 20

Which of the following has the lowest albedo? A. Forest B. Farms C. Desert D. Grassland

A. Forest

What Philippine climate type should be classified for an area that receives abundant rainfall almost the entire year but is very pronounced from November to April? A. Type 1 B. Type 2 C. Type 3 D. Type 4

B. Type 2

The type of Philippine climate where rain periods are maximum during the months of June to September and the places exposed to this climate are affected by the Southwest Monsoon. A. Type 1 B. Type 2 C. Type 3 D. Type 4

A. Type 1

What tropical cyclone warning signal (TCWS) should be raised if winds of about 200 kph is expected within 12 hours? A. 2 B. 3 C. 4 D. 5

D. 5

The statistical rule underlying in the assumptions of the normal distribution method. A. chi-square rule B. three-sigma rule C. Chebyshev’s rule D. probability rule

B. three-sigma rule

Using the float method in determining the velocity of water through a channel, the float velocity in relation to the average velocity is A. greater B. lesser C. equal D. neither greater nor lesser

A. greater

A typical orifice has a discharge coefficient of A. 0.25 B. 0.60 C. 1.42 D. 1.84

B. 0.60

That part of runoff which travels over the ground surface and through the channels to reach the basin outlet. A. interflow B. saturation flow C. overland flow D. direct runoff

D. direct runoff

The relationship established between stage and flow in a river. A. rating curve B. discharge sectioning C. shallow and deep channels D. control section

A. rating curve

This is the ratio of the standard deviation to the mean. A. skewness coefficient B. standard error C. variance D. coefficient of variation

D. coefficient of variation

A hydrologic process which is governed by chance and is time-dependent. A. rainfall B. stochastic C. probabilistic D. deterministic

B. stochastic

The distribution applicable to logarithmically transformed data which does not exhibit skewness anymore. A. Normal Distribution B. Log-Normal Distribution C. Log-Pearson Type III Distribution D. Kappa Distribution

B. Log-Normal Distribution

A barrier placed on a stream to constrict the flow of water and causes the water to fall over a crest, usually used for discharge measurement. A. orifice B. weir C. rating curve D. current meter

B. weir

The assumed state of flow in the derivation of the Chezy’s equation. A. steady uniform flow B. steady non-uniform flow C. unsteady uniform flow D. unsteady non-uniform flow

A. steady uniform flow

Which of the following can increase the rate of infiltration? A. low value of organic matter B. minimal tillage C. high temperature D. barren soil

C. high temperature

The main disadvantage of this method is the difficulty in obtaining initial rate of infiltration. A. Rainfall Simulation-Type Infiltrometer B. Catchment-Hydrograph Method C. Basin Method D. Horton method

C. Basin Method

Which of the following is not true for Lewis-Kostiakov? A. Applicable for small time values with permeable layer B. Applicable for soil underlain with impermeable layer. C. Will usually fit for experimental period of less than six hours. D. As time approaches infinity, the cumulative depth approaches zero

D. As time approaches infinity, the cumulative depth approaches zero

Which is not part of the process of infiltration? A. Passage of water into the soil surface B. Recharge to water table C. Filling up of the void spaces of the soil D. Downward transmission of the water in the soil

B. Recharge to water table

Which of the following terms does not mean the same thing as the others?A. water table B. vadose zone C. unsaturated zone D. zone of aeration

A. water table

The Philip equation of infiltration is based on A. regression analysis B. Darcy’s law C. the exhaustion process D. the equation of diffusivity

D. the equation of diffusivity

The normal discharge in the river A. Recession Limb B. Trough Flow C. Groundwater Flow D. Peak Flow

C. Groundwater Flow

This type of hydrograph is commonly used to simplify routing procedures. A. Rating Curve B. Unit hydrograph C. Basic hydrograph D. Triangular Hydrograph

D. Triangular Hydrograph

An aquifer which is underlain by a confining layer, has the potential for both vertical and horizontal flow, has the zero-gauge pressure line within the aquifer, and is comprised of both a saturated zone and a vadose zone will be defined as A. a confined aquifer B. an unconfined aquifer C. a homogeneous, isotropic aquifer D. a Darcian aquifer system

B. an unconfined aquifer

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

D. Aquitard

Which combination is attributed to having high values of pan coefficient?A. high wind speed on a fallow area B. low humidity on a cropped area C. high humidity on a fallow area D. low humidity on a fallow area

C. high humidity on a fallow area

Which part of the growth of plants has the largest crop coefficient value?A. Initial stage B. Crop Development C. Mid-Season D. Late Season

C. Mid-Season

What factor greatly contributes to the mass transfer effects in evapotranspiration? A. albedo change B. change in leaf area index C. height of crops D. water as a limiting factor

C. height of crops

Turbidity can be quantitatively measured in terms of NTU, which stands for A. No To drUgs B. Nephretic Turbidity Uniformity C. Nanometric Turbidity Unit D. Nephelometric Turbidity Unit

D. Nephelometric Turbidity Unit

Although clay soils have the highest total porosity, why is it not considered for well development? A. Clay soils have low water retention properties. B. Clay soils do not permit good drawdown curves. C. Clay soils have low safe yield. D. Clay soils have low water yield.

D. Clay soils have low water yield.

Which does not belong to the group? A. Nitrate, Methemoglobinemia B. Phospate, Eutrophication C. Fluoride, Irrigation Problems D. DO and pH, Fish Kill

C. Fluoride, Irrigation Problem

What is a commonly used indicator of possible health problems found in plants, soil, water and the intestines of humans and warm-blooded animals? A. Coliform bacteria B. Viruses C. Intestinal parasites D. Pathogenic organism

A. Coliform bacteria

What are the two main causes of hardness in water? A. Gold and silver B. Phosphate and nitrate C. Oxygen and methane D. Calcium and magnesium

D. Calcium and magnesium

It is the ratio of the volume of voids to the total volume of dry soil. A. Void ratio B. Bulk density C. Porosity D. Void density

A. Void ratio

The proportionality constant to determine the flow velocity of water through soils. A. Hydraulic potential gradient B. Uniformity coefficient C. Coefficient of proportionality D. Coefficient of permeability

D. Coefficient of permeability

The establishment of the National Irrigation Administration was the highlight of this episode. A. Japanese Regime B. Expansion Period C. Commonwealth Regime D. Early Independence Period

D. Early Independence Period

It is the ratio of the dry mass of the soil particles to the mass of water having the same volume as these particles A. Apparent Specific Gravity B. Real Specific Gravity C. Bulk Density D. Particle Density

B. Real Specific Gravity

The moisture content of the soil when the gravitational water has been removed. A. Readily available moisture B. Porosity C. Field capacity D. Permanent wilting point

C. Field capacity

The Atterberg Soil Classification Chart describes sand as a soil particle with a diameter of A. 0.002 to 0.2 mm B. 0.002 to 0.02 mm C. 0.20 to 2 mm D. 0.02 to 2 mm

D. 0.02 to 2 mm

The water that exists in the pore spaces of the soil and is retained against the force of gravity in a soil that permits unobstructed drainage A. Hygroscopic Water B. Capillary Water C. Gravitational Water D. Available Water

B. Capillary Water

The equation to estimate evapotranspiration using only extra-terrestrial radiation and air temperatures. A. Penman B. Hargreaves C. Blaney-Criddle D. Thornthwaite

B. Hargreaves

In developing a cropping pattern, harvesting of rice is usually scheduled on a period where A. labor is not limited B. irrigation water supply is abundant C. rainfall is maximum in the season D. solar radiation is at its seasonal peak

D. solar radiation is at its seasonal peak

These factors affect the variation of crop coefficient with the time/stage of crop growth, except for A. limiting nutrients in the soil B. changing height of crops C. changing albedo D. limiting presence of water

A. limiting nutrients in the soil

This is considered as a beneficial outflow in a water balance equation. A. net seepage B. deep percolation C. irrigation supply D. evapotranspiration

D. evapotranspiration

The ratio between water stored in the soil root zone during irrigation and the water delivered to the farm expressed in percent A. water storage efficiency B. application efficiency C. conveyance efficiency D. water use efficiency

B. application efficiency

The ratio of water stored in the root zone during the irrigation to the water needed in the root zone prior to irrigation, expressed in percent A. water use efficiency B. application efficiency C. water storage efficiency D. conveyance efficiency

C. water storage efficiency

The probability associated with dependable rainfall for a normal year A. 10% B. 20% C. 50% D. 80%

C. 50%

When the gravitational forces dominate over inertial forces in a fluid flow, the flow is classified as A. supercritical flow B. laminar flow C. turbulent flow D. subcritical flow

D. subcritical flow

When its cross-section is the same throughout its entire stretch, the channel is called a A. prismatic channel B. rectangular channel C. artificial channel D. natural channel

A. prismatic channel

For an infinitely wide channel, it is best to assume a hydraulic radius equal to A. hydraulic depth B. depth of flow C. half the depth of flow D. half of the hydraulic depth

B. depth of flow

A supercritical flow is a flow condition where A. Fr>1, high stage B. Fr>1, low stage C. Fr<1, high stage D. Fr<1, low stage

B. Fr>1, low stage

Structure installed at the head of conveyance canals or main canals to regulate the amount of water to be distributed A. Main canal B. Headgate C. Diversion Dam D. Irrigation Structures

B. Headgate

The flow combination associated with a gradually expanding channel under a constant discharge A. unsteady uniform flow B. unsteady non-uniform flow C. steady uniform flow D. steady non-uniform flow

D. steady non-uniform flow

This is a concrete structure usually built along the bank of a river or stream and which draws water to be channeled into an irrigation systemA. Diversion Dam B. Check Gate C. Secondary Gate D. Intake Structure

D. Intake Structure

A structure used to convey irrigation water across and above natural depressions such as rivers or creeks A. Elevated Flume B. Inverted Siphon C. Bench Flume D. Parshall Flume

A. Elevated Flume

Distribution control structures placed across an irrigation ditch to temporarily block the flow and to raise the upstream water level A. Culverts B. Weirs C. Turnouts D. Checks

D. Checks

These surface irrigation systems carry water down the land slope between crop rows. A. Border Irrigation B. Bedding Irrigation C. Basin Irrigation D. Furrow Irrigation

D. Furrow Irrigation

The subsurface drain system where laterals join the submain on both sides alternately. A. Herringbone System B. Gridiron System C. Parallel Drain System D. Double Main System

A. Herringbone System

The type of surface drainage system suitable in fields that do not require complete drainage with equally spaced laterals A. Gridiron B. Herringbone C. Natural System D. Parallel Drain System

C. Natural System

The following are the benefits of drainage, except A. Improves the soil structure and increases soil productivity B. Favors growth of soil bacteria C. Shortens the crop-growing season D. Seeps excess salts from the soil

C. Shortens the crop-growing season

This is the accumulation of excess water in the root zone of the soil A. Salinization B. Leaching C. Ponding D. Waterlogging

D. Waterlogging

This method of irrigation is observed in the rice terraces. A. Border Irrigation B. Bedding Irrigation C. Basin Irrigation D. Furrow Irrigation

C. Basin Irrigation

The higher the water pressure is in the sprinkler system, ________________________. A. The higher the efficiency of the system will be. B. The larger the droplets from the sprinkler nozzle are. C. The limited the sprinkler throw is. D. The higher the discharge is.

D. The higher the discharge is.

What construction procedure can reduce the effect of water hammer through buried pipes conveying irrigation water? A. Sand bedding B. Proper pipe fitting C. Reduce connections and fittings D. Operate at a much lower pressure

A. Sand bedding

Sprinkler irrigation is a versatile means of applying water to any crop, soil, and topographic condition. Except for one, it is particularly popular in humid regions because: A. Pipes are easily transported and provide no obstruction to farm operations when irrigation is not needed B. Surface ditches and prior land preparation are necessary for its operation. C. It is suitable for sandy soils or any other soil and topographic condition where surface irrigation may be inefficient or expensive, or where erosion may be particularly hazardous. D. Low rates and amounts of water may be applied; such are required for seed germination, frost protection, and cooling of crops in hot weather.

B. Surface ditches and prior land preparation are necessary for its operation.

The type of surface drainage system suitable for flat, poorly drained soils that have numerous shallow depressions A. Random Ditch System B. Interception Ditch System C. Parallel Lateral Ditch System D. Bedding System

C. Parallel Lateral Ditch System

SWCE Flashcards

(91 cards)