Practice Test: Hydrology and Soil and Water Conservation Engineering

Question 1

The factor that affects adoption of soil and water conservation measures

a. land tenure
b. high initial investment cost
c. construction skills
d. both a and b
e. all of the above

Answer 1

e. all of the above

Question 2

Which of the following irrigation projects is under the implementation and supervision of National Irrigation Administration?

a. Small Farm Reservoir (SFR)
b. Small Water Impounding Project (SWIP)
c. Communal Irrigation System (CIS)
d. None of the above
e. All of the above

Answer 2

c. Communal Irrigation System

Question 3

The detachment and transport of soil by a concentrated flow of water

a. sheet erosion
b. interill erosion
c. rill erosion
d. streambank erosion
e. none of the above

Answer 3

c. rill erosion

Question 4

The ratio of the circumference of a circle of the same area as the basin, to the basin perimeter

a. circulatory ratio
b. elongation ratio
c. circumferential ratio
d. relief ratio
e. none of the above

Answer 4

a. circulatory ratio

Question 5

A stream that flows only in direct response to precipitation

a. perennial stream
b. intermittent stream
c. ephemeral stream
d. both a and b
e. both b and c

Answer 5

c. ephemeral stream

Question 6

A hydrograph with a unit volume of direct runoff for a given storm duration

a. unit hydrograph
b. basic hydrograph
c. runoff hydrograph
d. synthetic hydrograph
e. dimensionless hydrograph

Answer 6

a. unit hydrograph

Question 7

Which of the following is not a purpose of terracing?

a. to reduce soil erosion
b. for water conservation
c. for flood control
d. for soil fertility rejuvenation
e. none of the above

Answer 7

d. for soil fertility rejuvenation

Question 8

It is an organic synthetic permeable cloth-like material used for soil conservation and erosion prevention

a. Geotextile
b. Geosynthetics
c. Geomeshscreen
d. both a and b
e. all of the above

Answer 8

d. both a and b

Question 9

Open channel flow is uniform flow and the continuity equation applies when

a. energy grade line and hydraulic grade line are parallel
b. hydraulic grade line and channel bed are parallel
c. energy grade line and channel bed are parallel
d. energy grade line, hydraulic grade line, and channel bed are parallel
e. all of the above

Answer 9

d. energy grade line, hydraulic grade line, and channel bed are parallel

Question 10

When the viscous forces are weak relative to inertial forces, the flow is

a. laminar
b. turbulent
c. transitional
d. critical
e. uniform

Answer 10

b. turbulent

Question 11

A channel having a steep slope

a. flume
b. chute
c. drop spillway
d. drop inlet
e. spillway

Answer 11

b. chute

Question 12

Is the elevation or vertical distance of the free water surface above a datum

a. stage
b. depth of flow
c. hydraulic depth
d. channel depth
e. both a and b

Answer 12

a. stage

Question 13

The Manning’s roughness coefficient for grassed channels or waterways is specifically known as

a. resistance coefficient
b. retardance coefficient
c. impedance coefficient
d. none of the above
e. all of the above

Answer 13

b. retardance coefficient

Question 14

The following measures accelerates channel flow, except,

a. channel deepening
b. channel straightening
c. channel widening
d. levees
e. vegetative control

Answer 14

e. vegetative control

Question 15

The distance between adjacent terraces

a. horizontal distance
b. vertical distance
c. horizontal interval
d. vertical interval
e. none of the above

Answer 15

d. vertical interval

Question 16

Which is not an element of flood routing?

a. inflow hydrograph
b. outflow hydrograph
c. spillway hydrograph
d. overflow discharge
e. available storage

Answer 16

d. overflow discharge

Question 17

Precipitation associated with the movement of air masses due to a difference in barometric pressure

a. convective
b. orographic
c. cyclonic
d. ITCZ
e. monsoon

Answer 17

c. cyclonic

Question 18

The method of determining average areal precipitation which accounts for the effect of topography and unequal gage density

a. arithmetic average
b. thiessen method
c. isohyetal method
d. both a and b
e. both b and c

Answer 18

e. both b and c

Question 19

Approximately ______ of the water extracted by the plant roots is transpired.

a. 75-79%
b. 80-84%
c. 85-89%
d. 90-94%
e. 95-99%

Answer 19

e. 95-99%

Question 20

The passage of water into the soil surface.

a. infiltration
b. seepage
c. percolation
d. leaching
e. both and b

Answer 20

a. infiltration

Question 21

Part of the runoff which travels over the ground surface and through the channels to reach the basin outlet.

a. surface runoff
b. overland flow
c. direct runoff
d. both a and b
e. all of the above

Answer 21

e. all of the above

Question 22

The time it takes for the runoff from the remotest point of the watershed to reach the outlet.

a. time to peak
b. time of concentration
c. recession time
d. runoff time
e. base time

Answer 22

b. time of concentration

Question 23

An equation or method used in the estimation and representation of evapotranspiration rate

a. Hargreaves Equation
b. Horton’s Equation
c. Lewis-Kostiakov Equation
d. Rational Equation
e. Gardner and Windsoe Equation

Answer 23

a. Hargreaves Equation

Question 24

Erosion which produces channels large enough to be obliterated by normal tillage

a. interill erosion
b. rill erosion
c. gully erosion
d. scour erosion
e. streambank erosion

Answer 24

c. gully erosion

Question 25

The rate of evapotranspiration occurring under field conditions for the given crop, soil moisture, and meteorological conditions a. potential evapotranspiration b. reference crop evapotranspiration c. actual crop evapotranspiration d. total crop evapotranspiration e. none of the above

Answer 25

c. actual crop evapotranspiration

Question 26

Fraction of sheet and rill erosion that actually reaches has reference point of discharge a. runoff coefficient b. sediment coefficient c. sediment delivery ratio d. erosion delivery ratio e. both c and d

Answer 26

c. sediment delivery ratio

Question 27

Water flows uniformly with a depth of 1.5 feet in a concrete-lined and trowel-finished trapezoidal canal (n=0.013) with a bottom width of 5 feet, side slope of 1:2, and a channel slope of 0.075%. Find the discharge in m3/s. a. 0.478 b. 0.487 c. 0.748 d. 0.784 e. 0.847

Answer 27

d. 0.784

Question 28

At what depth will water flow in a 3-m wide rectangular channel if n=0.015 s= 0.05° Q= 4 m3/s a. 0.56 m b. 0.66 m c. 0.76 m d. 0.86 m e. 0.96 m

Answer 28

e. 0.96 m

Question 29

A trapezoidal main canal of a large River Irrigation System has a top and bottom width of 15m and 6m, respectively. The side slope is 1 ½:1 and the canal is lined with concrete, for which 𝘯 is assumed to be 0.015. If it is to carry 45 m3/s of water, what must be the grade of the canal, in percentage and in degrees? a. 0.02%, 0.1° b. 0.01%, 0.2° c. 0.2%, 1° d. 0.1%, 2° e. 2%, 10°

Answer 29

a. 0.02%, 0.1°

Question 30

A trapezoidal main canal of a large River Irrigation System has a top and bottom width of 15m and 6m, respectively. The side slope is 1 ½:1 and the canal is lined with concrete, for which 𝘯 is assumed to be 0.015. If it is to carry 45 m3/s of water, what must be the grade of the canal, in percentage and in degrees? (Refer to the Problem above) If the flow in the canal were to decrease by 15 m3/s. All other data, including slope being the same, what would be the depth of the water? a. 1.45 m b. 1.54 m c. 2.45 m d. 2.54 m e. 3.45 m

Answer 30

c. 2.45 m

Question 31

If the most efficient of all trapezoidal cross sections can be used, what depth of open channel would you recommend to carry 100 cumecs with a with a velocity of 5 mps? a. 1.4 m b. 2.4 m c. 3.4 m d. 1.3 m e. 2.3 m

Answer 31

c. 3.4 m

Question 32

The critical depth of a triangular smooth concrete flume (n=0.012) is 2.61 ft. If the side slope is 2:1, determine the discharge. a. 80 cfs b. 82 cfs c. 84 cfs d. 88 cfs e. 92cfs

Answer 32

d. 88cfs

Question 33

A rain gage was inoperable during the month of June 2004. The rainfall totals for the three surrounding stations X, Y, Z during the same month are 5.50, 6.25, and 5.85 inches, respectively. The normal annual precipitation amounts of the station and of X, Y, Z are 80, 73, 79, and 86 inches, respectively. Estimate the amount of rainfall for the station on June 2004. a. 4.70 in b. 5.80 in c. 5.83 in d. 5.87 in e. 5.90 in

Answer 33

d. 5.87 in

Question 34

A water impounding reservoir with a capacity of 1500 m3 was constructed on a catchment area of 100 ha. If the annual streamflow averages 12.5 cm and the annual sediment production is 4.26 m3/ha, what is the probable life of the reservoir before its capacity is reduced to 500 m3? a. 6 years b. 7 years c. 8 years d. 9 years e. 10 years

Answer 34

c. 8 years

Question 35

What is the trap efficiency of the reservoir in Problem No. 34? a. 15% b. 20% c. 25% d. 30% e. 35%

Answer 35

d. 30%