PAES 601

Question 1

PAES 601:2016?

Answer 1

General Irrigation Terminologies

Question 2

areas open for public entry such as golf courses, public and private parks,
playgrounds, schoolyards and playing fields, residential landscapes and industrial
park landscapes

Answer 2

access areas

Question 3

volume of water stored in reservoir between the minimum water level and normal
water level

Answer 3

active storage

Question 4

rate of evapotranspiration equal to or smaller than predicted crop evapotranpiration as
affected by the level of available soil water, salinity, field size or other causes

Answer 4

actual crop evapotranspiration

Question 5

rise in maximum flood level from the original unobstructed flood level which result
after an obstruction to the flow such as a dam, has been introduced

Answer 5

afflux elevation

Question 6

overgrowths of algae in water producing dangerous toxins in fresh or marine water

Answer 6

algal bloom

Question 7

ratio of the average depth of irrigation water infiltrated and stored in the root zone to
the average depth of irrigation water applied

Answer 7

application efficiency

Question 8

geologic formation which contains water and transmits it at a rate sufficient to be
economically developed for pumping artificially developed well

Answer 8

aquifer

Question 9

cross-sectional area of the flow which is measured perpendicular to the direction of
flow

Answer 9

area

Question 10

field that is level in all directions, encompassed by a dike to prevent runoff, and
provides an undirected flow of water onto the field

Answer 10

basin

Question 11

type of surface irrigation where water is applied to the basin through a gap in the
perimeter dike or adjacent ditch; water is retained until it infiltrates into the soil or the
excess is drained off

Answer 11

basin irrigation

Question 12

maximum average contact pressure between the foundation and the soil which should
not produce shear failure in the soil

Answer 12

bearing capacity

Question 13

method of irrigation which makes use of parallel border strips where the water flows
down the slope at a nearly uniform depth

Answer 13

border irrigation

Question 14

area of land bounded by two border ridges or dikes that guide the irrigation stream
from the inlet point of application to the ends of the strip

Answer 14

border strip

Question 15

inclination or elevation drop per unit length of the channel bottom

Answer 15

channel bed slope

Question 16

groundwater that is confined by relatively impermeable layer

Answer 16

confined aquifer

Question 17

introduction of substances not found in the natural composition of water that make the
water less desirable or unfit for intended use

Answer 17

contamination

Question 18

ratio between water received at the inlet for a block of fields to that released at the
project’s headwork

Answer 18

conveyance efficiency

Question 19

loss of water from a channel during transport due to seepage and percolation

Answer 19

conveyance loss

Question 20

depth of water flow where the energy content is at minimum hence, no other
backwater forces are involved

Answer 20

critical depth

Question 21

ratio of the actual crop evpotranspiration to its potential evapotranspiration

Answer 21

crop coefficient

Question 22

ratio of the actual crop evpotranspiration to its potential evapotranspiration

Answer 22

crop coefficient

Question 23

rate of evapotranspiration of a disease-free crop growing in a large field (one or more
ha) under optimal soil conditions, including sufficient water and fertilizer and
achieving full production potential of that crop under the given growing environment;
includes water loss through transpiration by the vegetation, and vaporation from the
soil surface and wet leaves

Answer 23

crop evapotranspiration

Question 24

sequence of different crops grown in regular order on any particular field or fields

Answer 24

cropping pattern

Question 25

any barrier constructed to store water

Answer 25

dam

Question 26

vertical distance from lowest point of the ground line to the dam crest

Answer 26

dam height

Question 27

volume below the intake structure; sediment volume based on 25 years of accumulation in the reservoir

Answer 27

dead storage

Question 28

depth of water in the channel cross-section

Answer 28

depth

Question 29

actual height of the embankment after settlement

Answer 29

designed height

Question 30

maximum area which an irrigation project can serve considering the extent of arable lands and the available water supply

Answer 30

design irrigable area

Question 31

numerical value on the uniformity of application for agricultural irrigation systems

Answer 31

distribution uniformity

Question 32

structure or weir provided across the river or creek to raise its water level and divert the water into the main canal to facilitate irrigation by gravity

Answer 32

diversion dam

Question 33

the total quantity of water diverted from a stream, lake, or reservoir, or removed from the ground in order to irrigate a crop

Answer 33

diversion water requirement

Question 34

trickle irrigation involves dripping water onto the soil at very low rates (2-20 litres/hour) from the emitters where water is applied close to plants so that only part of the soil in which the roots grow is wetted

Answer 34

drip irrigation

Question 35

in-line canal structure designed to convey canal water from a higher level to a lower level, duly dissipating the excess energy resulting from the drop in elevation

Answer 35

drop

Question 36

amount of rainwater that falls directly on the field and is used by the crop for growth and development excluding deep percolation, surface runoff and interception

Answer 36

effective rainfall

Question 37

soil depth from which the bulk of the roots of the crop extracts most of the water needed for evapotranspiration

Answer 37

effective rooting depth

Question 38

effective size | -particle diameter corresponding to a ____ sieve passing

Answer 38

10%

Question 39

discharges from known sources which is passed into a body of water or land, or wastewater flowing out of a manufacturing plant, industrial plant including domestic, commercial and recreational facilities

Answer 39

effluent

Question 40

any legal restriction or limitation on quantities, rates, and/or concentrations or any combination thereof, of physical, chemical or biological parameters of effluent which a person or point source is allowed to delivery into a body of water or land

Answer 40

effluent standard

Question 41

water conveying conduit or trough which is supported on abutments by piers

Answer 41

elevated flume

Question 42

spacing between emitters or emission points along a lateral line

Answer 42

emitter spacing

Question 43

applicator used in drip, subsurface, or bubbler irrigation designed to disspate pressure and to discharge a small uniform flow or trickle of water at a constant rate that does not vary significantly because of minor differences in pressure

Answer 43

emitters

Question 44

specific energy line | grade line of the water surface profile plus the velocity head in open channels

Answer 44

energy grade line

Question 45

provision for passing of equipment and small machinery

Answer 45

equipment crossing

Question 46

combination of water transpired from vegetation and evaporated from the soil, water, and plant surfaces.

Answer 46

evapotranspiration

Question 47

channel which conveys irrigation water from the turnout to the paddy field

Answer 47

farm ditch

Question 48

dam component which prevents migration of small particles and screen off fine materials that flow with seepage water and prevent piping

Answer 48

filter drain

Question 49

height of the embankment to be attained during construction

Answer 49

finished height

Question 50

amount of water to replenish the crop water requirement and losses less the effective rainfall

Answer 50

farm water requirement

Question 51

additional height of the dam provided as a safety factor to prevent overtopping by wave action or other cause

Answer 51

freeboard

Question 52

small parallel channels, made to carry water in order to irrigate the crop

Answer 52

furrows

Question 53

method of irrigation where water runs through small parallel channels as it moves down the slope of the field

Answer 53

furrow irrigation

Question 54

small channel along one part of a field that is used for distributing water in surface irrigation

Answer 54

head ditch | supply ditch

Question 55

dam composed of a single kind of embankment material exclusive for slope protection

Answer 55

homogeneous embankment

Question 56

ratio of flow area to the wetted top width

Answer 56

hydraulic depth

Question 57

profile of the free water surface

Answer 57

hydraulic grade line

Question 58

occurs when a thin sheet of incoming flow moving at high velocity strikes water of sufficient depth

Answer 58

hydraulic jump

Question 59

cross-sectional area of flow divided by the wetted perimeter

Answer 59

hydraulic radius

Question 60

estimation of the chance or likelihood of occurrence of a given event by determining the frequency curves of best fit to samples of hydrologic data

Answer 60

hydrologic frequency analysis

Question 61

inside slope

Answer 61

slope of the upstream face of the embankment

Question 62

inside bottom or sill of t the conduit

Answer 62

invert

Question 63

closed conduit designed to convey canal water in full and under pressure running condition, to convey canal water by gravity under roadways, railways, drainage channels and local depressions

Answer 63

inverted siphon

Question 64

time required to cover an area with one application of water

Answer 64

irrigation period