SWCE

Question 1

Maximum water quantity that can be guaranteed during critical period

Answer 1

Safe yield

Question 2

Dams that can only be used in narrow canyons

Answer 2

Arch dam

Question 3

Water level in a group of artesian wells

Answer 3

Water table

Question 4

What is the best method of irrigation for irregular topography?

Answer 4

Sprinkler

Question 5

What is the best method of irrigation for row crops?

Answer 5

Furrow

Question 6

Which irrigation method has the best control of water supplied?

Answer 6

Sub-irrigation

Question 7

Locus of the elevation to which water will rise in a piezometric tube

Answer 7

Hydraulic gradient

Question 8

The sheet of water which is flowing over the crest of a dam or weir

Answer 8

Nappe

Question 9

The flow that occurs when the velocity is larger than the critical velocity and the depth is smaller than the critical depth

Answer 9

Super critical

Question 10

For dam called SWIM projects the volume storage should not exceed (in million m2)

Answer 10

50

Question 11

needed in estimating runoff, planning erosion control measures, planning for irrigation and drainage, and water conservation in low rainfall regions

Answer 11

precipitation

Question 12

needed in designing structures and channels that will handle natural flows of water

Answer 12

runoff

Question 13

required in planning irrigation and drainage systems, moisture conservation practices, etc.

Answer 13

Infiltration, Evaporation and transpiration

Question 14

caused by the rising of warmer, lighter air in colder, denser surroundings.

Answer 14

Convective Precipitation

Question 15

results from mechanical lifting of the air mass over mountain barriers.

Answer 15

Orographic Precipitation

Question 16

air is lifted through horizontal convergence of the inflow into a low pressure area

Answer 16

Non-frontal

Question 17

associated with the movement of air masses from high-pressure to low-pressure regions.

Answer 17

Cyclonic Precipitation

Question 18

lifting of warm air over cold air at the contact zone between air masses having different characteristics

Answer 18

Frontal

Question 19

this involves the averaging arithmetically all the rainfall depths measured by the rain gages within the area.

Answer 19

Arithmetic mean

Question 20

– location of the rain gauges are plotted on the map of the area and stations are connected by straight lines. Perpendicular bisectors are constructed on each of the connecting lines thereby forming polygons enclosing each rain gage. The average rainfall over the area is then estimated as the area weighted average for all polygons

Answer 20

Thiessen polygon

Question 21

station locations and amounts of rainfall are plotted on a suitable map, and contours of equal precipitation (isohyets) are then drawn. The equation used is similar to that of Thiessen method except that the area, Ai, is the area under one isohyet, Pi.

Answer 21

Isohyetal

Question 22

computer aided method wherein it averages estimated precipitation at all points of a superimposed grid.

Answer 22

Grid-Point Method

Question 23

for rolling areas and non-uniform distribution of gages, distance factor fixed by location of gages is used for analysis using this method. It operates under the principle that the value of points close together in space are more likely to be similar than with points farther apart.

Answer 23

Inverse Distance Ratio Method

Question 24

the number of years during which one storm of a given duration and intensity is expected to occur.

Answer 24

frequency or recurrence interval

Question 25

one in which a definite law of certainty exists

Answer 25

Deterministic Process

Question 26

governed by chance; time series INDEPENDENT

Answer 26

Probabilistic Process

Question 27

governed by chance; time series DEPENDENT

Answer 27

Stochastic Process

Question 28

data is more or less normally distributed

Answer 28

Normal Distribution

Question 29

used when there is skewness in the data distribution

Answer 29

Log-Normal Distribution

Question 30

considers further the skewness of the logarithmically transformed hydrologic data; preferred for flood flow frequency; log-normal distribution is a special case of this method

Answer 30

Pearson Type III Distribution

Question 31

so far gives the best fit for most stations for 1-week, 2-week, 3-week and monthly rainfall totals of the country

Answer 31

Gamma Density Function

Question 32

that which travels over the ground surface and through the channels to reach the basin outlet

Answer 32

Surface Runoff

Question 33

that which infiltrates into the soil surface and moves laterally through the upper soil horizons towards streams as perched groundwater above major groundwater level

Answer 33

Interflow

Question 34

roundwater discharge into a stream due to deep percolation of the infiltrated water into groundwater aquifers

Answer 34

Groundwater Runoff

Question 35

that part of surface runoff that flows over the surface towards the stream channel

Answer 35

Overland flow

Question 36

surface runoff plus interflow

Answer 36

Direct runoff

Question 37

same as interflow

Answer 37

Subsurface runoff

Question 38

same as groundwater runoff

Answer 38

Baseflow

Question 39

used to determine the magnitude of floods and a valuable consideration in the design of structures

Answer 39

Peak Flow (qp)

Question 40

used for flood forecasting and water quality studies; watershed response time

Answer 40

Time to Peak (tp)

Question 41

total water yield from a storm for a given watershed

Answer 41

Recession Time (tr)

Question 42

total of time to peak and recession time; (tb) = (tp) + (tr)

Answer 42

Base time (tb)

Question 43

low flow, dependable flow, groundwater discharge

Answer 43

Base flow

Question 44

a graphical representation of the instantaneous runoff rate against time. The area under it gives the runoff volume.

Answer 44

hydrograph

Question 45

– assumes that all hydrographs from all small watersheds (in the US) have similar forms
– it is plotted over 100 arbitrary units of flow and 100 arbitrary units of time

Answer 45

Basic Hydrograph

Question 46

approximation of the basic hydrograph
- - developed mainly to simplify flood routing procedures in US

Answer 46

Triangular Hydrograph

Question 47

a hydrograph with a unit volume (e.g. 1cm) of direct runoff for a given storm duration
represent the response of the basin on a given storm duration and characteristics
- - enables one to synthesize hydrographs for complex storms by superimposing the hydrographs resulting from the individual components of the storm

Answer 47

Unit Hydrograph

Question 48

prepared using data from a number of watershed to develop dimensionless unit hydrographs which are applicable to ungaged watersheds
a dimensionless hydrograph is made from natural or unit hydrographs in which the time to peak (tp) and the peak runoff rate (qp) are considered an t/tp is plotted against q/qp

Answer 48

Synthetic Hydrograph

Question 49

provide record of the highest stage observed at a stream

Answer 49

Crest Stage Gage

Question 50

record the pressure required to maintain a small flow of gas from an orifice submerged in the stream

Answer 50

Bubbler Gage

Question 51

motion of a float is recorded on a graph

Answer 51

Float-type Water-Stage Recorder

Question 52

measures the velocity of a floating object preferably in a straight section of a stream

Answer 52

Float method

Question 53

utilizes the equation or relation:

V = a + bN

Where: V – water velocity
a – starting velocity or velocity required to overcome mechanical friction
b – constant of proportionality
N – revolution per seconds of the meter cups / propeller

Answer 53

Propeller-type Meter (Current Meters)

Question 54

Type of water erosion, primarily caused by raindrop

Answer 54

Splash / Raindrop Erosion

Question 55

Type of water erosion, a thin film of soil layer detached and transported by water flowing on the land surface.

Answer 55

Sheet erosion

Question 56

Type of water erosion, combination and splash and sheet erosion

Answer 56

Interrill erosion

Question 57

Type of water erosion, advanced stage of rill erosion. Rills when neglected develop in size and become gullies.

Answer 57

Gully erosion

Question 58

Type of water erosion, erosion of stream banks by flowing water

Answer 58

Stream bank erosion

Question 59

Type of water erosion, erosion caused by wave action on the seashore

Answer 59

Coastal erosion

Question 60

Type of water erosion, finger-like rills appear on the soil surface

Answer 60

Rill erosion

Question 61

caused by high velocity winds moving over barren land surfaces.

Answer 61

Wind erosion

Question 62

land slides and slips due to saturation of steep hills and slopes.

Answer 62

Slip erosion

Question 63

replanting of forest trees species in the watershed area

Answer 63

Reforestation

Question 64

a practical adaptation of reforestation whereby the species planted have economic value, such as mango, pili and so on.

Answer 64

Agroforestry

Question 65

is the practice of growing different crops in alternate strips across the slope to serve as barriers for soil erosion.

Answer 65

Strip cropping

Question 66

the process of covering the land surface with plant residues, plastic or other materials appropriate to arrest loss of moisture through evaporation

Answer 66

Mulching

Question 67

consists of carrying out agricultural operations very nearly on the contour. It reduces the velocity of overland flow and retards soil erosion

Answer 67

Contour cultivation

Question 68

modification of cropping system such as crop rotation and mixed cropping

Answer 68

Cropping systems

Question 69

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.

Answer 69

Terracing

Question 70

establishment of natural waterways or construction of canals and planting it with grasses to make it stable and arrest soil erosion

Answer 70

Grassed Waterways

Question 71

constructed along the channel or waterway to control the velocity of flowing water and encourage deposition of sediments carried by water

Answer 71

Check dams or weirs

Question 72

temporary detainment of water in farm pond and dams to mitigate the erosive capacity of water

Answer 72

Farm Ponds / Water Impounding Dams

Question 73

a channel constructed around the slope and given a slight gradient to cause water to flow to a suitable and stable outlet.

Answer 73

Diversion Canal

Question 74

concrete structure made of stones constructed along steep embankments to prevent landslide or gully erosion

Answer 74

Riprap

Question 75

made of stones carefully and properly piled-up and arranged on steep embankments to protect from gully erosion or landslide

Answer 75

Stone wall

Question 76

usually starts as small rills and gradually develops into deeper crevices

Answer 76

Gully erosion

Question 77

is constructed across the slope above the gully. The grassed waterway intercepts the runoff coming from above the gully

Answer 77

Grassed waterways

Question 78

can stabilize the slopes of the gully and hence reduce runoff velocities.

Answer 78

Vegetation

Question 79

construction of series of platforms along the contours cut into the hill slope in a step like formation

used for 25-30% slopes
used for maximum moisture conservation
used where land is at a premium
conventional
difficult to farm

Answer 79

Bench

Question 80

-primary purpose is to remove excess water in such a way as to minimize erosion
-reduce slope length, conducts intercepted runoff water to outlet at non-erosive velocity
-outlet either surface or subsurface type

Answer 80

Broad-based Graded or channel type

Question 81

-used for 9-24% slope
-easier to farm than conventional
-used for maximum soil and water conservation

Answer 81

Zingg or Conservation bench terrace

Question 82

-no grade in channel
-primary purpose is moisture conservation, erosion control is secondary
-channel is normally closed at both ends to assure maximum detention
-adopted to deep, permeable soils
more formable than bench types
-used where outlets are a problem

Answer 82

Broad-based, Level or ridge type

Question 83

no grade in channel
primary purpose is moisture conservation, erosion control is secondary
channel is normally closed at both ends to assure maximum detention
adopted to deep, permeable soils
more formable than bench types
used where outlets are a problem

Question 84

are open channels protected with suitable grasses constructed along the slope and act as outlet for terraces and graded bunds. They are also used to safely convey runoff from contour furrows, diversion channels and serve as emergency spillways in farm ponds.

The velocity of flow is dependent upon the ability of the vegetation to resist erosion. For design purposes, an average of 1.5 m/s to 2 m/s is used.

Answer 84

Grassed Waterways

Question 85

Structures constructed along a channel to dissipate safely the energy of water by letting the water fall freely for a certain height.

Answer 85

Drop structures

Question 86

A term adapted to measures utilizing both or in combination with the biological and engineering measures.

Answer 86

Vengineering

Question 87

discharge is constant with respect to time

Answer 87

Steady Flow

Question 88

if the depth changes abruptly over a comparatively short distance such as in a hydraulic jump

Answer 88

Rapidly Varied Flow

Question 89

depth of flow is the same at every section of the prismatic channel

Answer 89

Uniform Flow

Question 90

discharge is not constant with respect to time

Answer 90

Unsteady Flow

Question 91

depth changes along the length of channel

Answer 91

Varied Flow

Question 92

if the depth changes smoothly over a distance

Answer 92

Gradually Varied Flow

Question 93

Fr = 1

Answer 93

Critical Flow

Question 94

fluid moves in parallel layers with no cross-currents; Re <= 2000

Answer 94

Laminar Flow

Question 95

Fr < 1

Answer 95

Subcritical Flow

Question 96

Fr > 1

Answer 96

Supercritical Flow

Question 97

characterized by pulsatory cross-current velocities; Re => 4000

Answer 97

Turbulent Flow

Question 98

special case of flow in which the discharge varies with distance along the channel

Question 99

is the elevation above some arbitrary zero datum of the water surface at a station along a river or stream.

Question 100

a scale set at the river/stream so that a portion of it is immersed in the water at all times to measure river stage.

Question 101

vulnerability or susceptibility of the soil to erosion. It is a function of both the physical properties of the soil and land management practices.

Question 102

is the detachment and transport of soil particles from the land by water or wind action.

Question 103

is soil detachment and transport resulting from the impact of water drops directly on soil particles or on thin water surfaces.

Question 104

detachment and transport of soil by concentrated flow of water creating shallow rills or furrows.

Question 105

potential ability of the rain to cause erosion. It is a function of the physical characteristics of the rainfall.

Question 106

consists of soil removal from stream banks or soil movement in the channel.

Question 107

detachment and transport of soil particles by concentrated flow of water creating channels larger and deeper than rills. As differentiated with rill, channels or gullies created cannot be obliterated by normal tillage operation. Thus gully erosion is an advanced stage of rill erosion.

Question 108

the depth of water in inches to be removed in a 24 hours period from the drainage area.

Question 109

structured device designed to hold a pool of water to cushion the impact and retard the flow of falling water as from an overflow weir, chute or drop.

Question 110

planting different crops simultaneously in the same field at the same cropping season.

Question 111

consist of growing alternate strip of clean cultivated and close-growing crops in the same field oriented across the slope.

Question 112

(crop rotation) planting different crops, one after the other each season.

Question 113

are specially shaped and stabilized channel sections which may also be used to measure flow and are generally less inclined than weirs to prevent floating debris and sediments from detention

Question 114

the ratio of depth of run-off to depth of precipitation producing the run-off over a drainage area.

Question 115

a natural body composed of mineral and organic material on the surface of the earth on which plants grow.

Question 116

closed conduit usually circular, square or rectangular in cross section, used for conveying water across and under an elevated roadway, embankments, or dike.

Question 117

the relative proportion of the various size groups of individual soil grain.

Question 118

a structure which conveys water from a higher to a lower level, maybe inclined or vertical.

Question 119

an imaginary line of constant elevation on the surface of the ground.

Question 120

the application of engineering principles to the solution of soil management problems, any method used to fully utilize and conserve soil.

Question 121

constructed by cutting a shallow channel on the uphill-side and using only this soil to build the embankment.

Question 122

study which deals with the relationship of the

physical environment and agricultural elements

Question 123

the study of animal and plant life cycle as

affected by seasonal variations of climate

Question 124

are usually found in universities
and research institutes/stations, to collect
meteorological and biological data

Question 125

The pressure under a gravity dam producing an overturning effect

Question 126

The most elaborate method of computing potential Evapotranspiration

Question 127

2 Methods of supplying water in the basin

Question 128

Banawe rice terraces is a.

Question 129

The soil contain more or less equal amounts of sand, silt and clay?

Question 130

A vertical section to the soil mass where significant changes in the soil texture and structure with depth are observed

Question 131

The moisture content of the soil when tension is 1/3 atmosphere

Question 132

This refer to the additional height or depth of hydraulic structures

Question 133

The rational method of determining runoff is applicable to.

Question 134

The other term for gravity well.

Question 135

Term for solar radiation received at the earth’s surface

Question 136

On the weather map, lines representing points of equal pressure is called.

Question 137

It is the measure in difference in the ground level between two places in the field and referred to as percentage. It is the number of meter difference in elevation for each 100 m horizontal distance

Question 138

The name for seasonal winds (derived from Arabic mausim, a season).

Question 139

The type of climate prevailing in region 1 and 2.

Question 140

The recommended variation in the lateral between the first and last sprinkle.

Question 141

A soil ph above 7.7.

Question 142

Pipelines built on or near the ground surface to convey water across wide depressions.

Question 143

Subsurface system wherein laterals join the submain on the both sides alternately.

Question 144

It is the water retained about individual soil particles by molecular action and can removed only by heating.

Question 145

The artificial application of water to the soil for the purpose of crop production.

Question 146

Small earth embankment or dam built around each basin to hold water without leakage while it is infiltrate.

Question 147

A piece of land divided into strips by small earth bunds usually sloping uniformly away from the farm channel in the direction of water flow to irrigate similar crops and soil.

Question 148

A small drain constructed at the end of each boarder to remove excess surface water .

Question 149

A hydraulic shock occur when water flowing to pipe undergoes sudden changes in velocity.

Question 150

The formation of cavities filled with the liquid vapor due to a local pressure drop and their collapse as soon as the vapor bubbles reach regions of high pressure .

Question 151

A notch of regular form through which the irrigation stream is made to flow and built as either portable or stationary structure.

Question 152

The most stable and chief component of most soil on volumetric basis

Question 153

Water held tightly to the surface of the soil particles by adsorption forces is called:

Question 154

Two pronounced seasons: dry from November to April: wet during the rest of the year. All provinces on the Western part of the rest of the year. All provinces on the Western part of the Islands of Luzon, Mindoro, Negros and Palawan are covered

Question 155

No pronounced season, relatively dry from November to April and wet during the rest of the year. This type of climate covers the Western portion of the Mountain Province, Southern Quezon the Bontoc Peninsula, Masbate, Romblon, Northeast Panay, Eastern Negros, Central and Southern Cebu, part of Northern Mindanao and most of Eastern Palawan

Answer 155

Type 1

Question 156

Rainfall more or less evenly distributed throughout the year. The areas covered by Type IV climate are Batanes Province, North-eastern Luzon, Western Camarines Norte and Camarines Sur, Albay, Eastern Mindoro, Marinduque, Western Leyte, Northern Negros and most of Central, Eastern and Southern Mindanao.

Question 157

No dry season with a very pronounced maximum rainfall from November to January. The areas covered are Catanduanes, Sorsogon, the Eastern part of Albay, the Eastern and Northern Parts of Camarines Norte, a great protion of the Eastern part of Quezon, the Eatern part of Leyte and a large portion of Eastern Mindanao

Question 158

is the study of the earth’s atmosphere

Question 159

is the branch of meteorology that
deals with the state of the atmosphere
averaged over a long period of time

Question 160

atmospheric condition over a short
duration, particularly the combination of
heat, moisture and wind characteristics
of the atmosphere in a day

Question 161

climate that prevail over a large region of the earth’s surface

Question 162

areas up to several square miles (e.g. river valleys, mountain areas, watersheds and basins, shores, urban areas)

Question 163

the total weather condition of an area
as generalized over a long period of
time, i.e. seasons, years, decades

Question 164

incoming sunlight

Question 165

fraction of the incident radiation that is reflected by an object

Question 166

the period when the sun is farthest from the earth (δ=23.450)

Question 167

over short distances, or within few feet or inches (e.g. streets, immediate plant surroundings, garden plot)

Question 168

sun’s position makes day and night equal (sun is directly above the observer: δ=0)

Question 169

Stronger high and low tides
During new and full moon (earth, moon and sun are parallel or in-line)
Moon’s pull is supplemented or offset by sun’s gravity

Question 170

Smaller high and low tides
Moon is in the 1st and 3rd quarter (forms 900with the sun)
Moon’s pull is stronger but the sun’s gravity lessens it.

Question 171

large-scale, seasonal version of the diurnal sea/land breeze that occurs along many coast, especially Arabian Sea and Indian Ocean

Question 172

fair weather clouds that are individual, woolly, cauliflower-like masses usually moving rapidly on a strong wind.

Question 173

ow, watery, almost featureless clouds of indefinite shape * When touching the ground, it is called fog.

Question 174

are wispy white clouds of tiny ice crystals * Also called ‘Mare’s tail’.

Question 175

rain clouds’

Question 176

heavy, swelling, cauliflower-like clouds that form the towering summer thunderbolts.

Question 177

Low pressure area around equator where prevailing winds are calm.

Question 178

are air-mass boundaries that lie along line of low pressure

Question 179

combination of the warm and cold front, where cold air overtakes and lifts the warm front

Question 180

the warm air advances and the cold air retreats

Question 181

the cold air advances and the warm air retreats

Question 182

temporarily fixed boundary between polar and tropical air masses

Question 183

storm in a region of low surface pressures

Question 184

Lowest barometric pressure (15% of the pressure outside the storm)
 surrounded by a ring of towering thunderstorm

Question 185

most severe weather condition

 30~65 km φ

Question 186

are the fastest most violent winds on earth - top speed of 110 kph near the ground and stay about 10 minutes (though a few monster tornadoes from a mile or more wide and can last for an hour or more)

Question 187

forms when moist, unstable air is lifted vertically into the atmosphere, resulting in condensation and the release of latent heat

Question 188

When temperature rises, the expanding mercury is forced past the constriction but when the temperature falls the column of mercury remains in the tube, thus indicating the maximum temperature

Question 189

It is basically a manometer with one end exposed to the atmosphere
It is more sensitive than aneroid barometer since it has Vernier scale on it and has already temperature, elevation and altitude corrections.

Question 190

To provide a standardized environment in which to put or keep the temperature- and humidity-measuring instruments.

It shields the instruments against rain and direct solar radiation while allowing air to circulate freely around them.

Question 191

A device that measures or records the amount of sunshine at a given location.

Question 192

A type of actinometer used to measure broadband solar irradiance (short wave radiation)

Question 193

Used to measure intensity of direct solar radiation

Question 194

A device which uses a laser or other light source to determine the height of a cloud base.

Question 195

A group of instruments for simultaneous measurement and radio transmission of meteorological data: temperature, pressure, and humidity of the atmosphere. The instrument package is usually carried into the atmosphere by a balloon.

Question 196

comprises 8 sensors for measuring wind speed, wind direction, air temperature, RH, solar radiation, soil temp., surface wetness, and rainfall.

Question 197

is a geologic formation or rather impervious nature which transmits water at a slow rate
compared to an aquifer.

Question 198

a geologic formation which can absorb water but cannot transmit significant amounts
Examples are clays and shales.

Question 199

is a geologic formation with no interconnected pores and hence can neither absorb nor
nor transmit water

Question 200

is the volume of water, expressed as a percentage of the total volume of the
saturated aquifer that will drain by gravity when the water table drops due to pumping or drainage

Question 201

is the percentage volume of water which will not drain by gravity. This
corresponds to the field capacity or the water holding capacity of soil.

Question 202

is a dimensionless or fractional quantity referring to the volume of water
given out by a unit prism of aquifer when the piezometric surface or the water table drops by unit depth
- it is the same as the volume of water taken into storage by a unit prism of the
aquifer when the piezometric surface or water table rises by unit depth.

Question 203

of a well, is the discharge per unit drawdown in the well. It is measure
of the effectiveness of the well and decreases with the increase in the pumping rate and prolonged pumping.

Question 204

is the process of breaking down rocks by mechanical and chemical process into
smaller pieces

Question 205

that part of atmospheric moisture that falls on the earth surface. It is
primary input into the hydrologic cycle.

Question 206

a light steady rain in fine drops, about 0.5 mm and intensity less than 1 mm/hr

Question 207

is the condensed water vapor of the atmosphere falling in drops (>0.5 mm,
maximum size is 6 mm) from the clouds.

Question 208

is the freezing of drizzle or rain when they come in contact with cold objects

Question 209

is the frozen rain drops which falling through air at subfreezing temperature.

Question 210

is the ice crystal resulting from sublimation; i.e., water vapor condenses to ice

Question 211

refers to small lumps of ice (3.5 mm diameter formed by alternate freezing
and melting, when they are carried up and down in highly turbulent air
currents.

Question 212

is moisture condensed from the atmosphere in small drops upon cool surfaces

Question 213

is a feathery deposit of ice formed on the ground or on the surface of exposed
object by dew or water vapor that has frozen

Question 214

is a thin cloud of varying sizes formed at the surface of the earth by condensation
of atmospheric vapor, usually interfering with visibility.

Question 215

is a very thin fog.

Question 216

equation that implies that at t → ∞, f = 0. This is only possible if the soil is
underlain by an impermeable layer. As such, the equation will only apply for soil underlain with
impervious layers or for small t values in soils with pervious layers.

Question 217

For this equation infiltration rate is a decay type function whereby continuous infiltration and
wetting of the soil will decrease infiltration due to decrease in soil profile storage potential, in
washing of fine soil particles into soil voids and swelling of soil colloids and closing of soil cracks.

Question 218

This equation it is analyzed infiltration as a general phenomenon of water movement in a
porous medium.

Question 219

stream with continuous flow and has considerable

contribution to the baseflow

Question 220

stream with periodic or seasonal flow

Question 221

stream with flow in direct response to rainfall

Question 222

refers to the physical characteristics, dissolved chemical constituents, and bacteriological quality of water, with reference to a specific use.

Question 223

Vegetative cover over the land surface of a catchment area.

Question 224

A zone in the soil just above the water table that remains saturated or almost saturated. The extent depends upon the size-distribution of pores.

Question 225

A measure of the quantity of cations a given mass of soil can hold. It is related to clay content and type, and organic matter content.

Question 226

describe the rate of flow of water through porous media. The rate of flow of water in porous media is proportional to, and in the direction of, the hydraulic gradient and inversely proportional to the thickness of the bed.

Question 227

A universal constant used in the equation relating the rate of emission of radiant energy from the surface of a body to the emissivity of the surface and the temperature of the body.

Question 228

Instrument, consisting of a porous cup filled with water and connected to a manometer or vacuum gage, used for measuring the soil-water matric potential.

Question 229

The rate at which water of a prevailing density and viscosity is transmitted through a unit width of an aquifer or confining bed under a unit hydraulic gradient. It is a function of properties of the liquid, the porous media, and the thickness of the porous media.