Soil and Water Conservation Engineering Flashcards by poodey pay

Slope of the upstream face of the embankment.
A. Downstream slope
B. Outside slope
C. Inside slope
D. Upstream slope

C. Inside slope

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Inside bottom or sill of the conduit.
A. Invert
B. Inside base
C. Inside sill
D. Bottom sill

A. Invert

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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.
A. Close siphon
B. Pressurized conduit
C. Siphon
D. Inverted siphon

D. Inverted siphon

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_______ water requirement is the amount of water required in lowland rice production which includes water losses through evaporation, seepage, percolation and land soaking.
A. Land preparation
B. Irrigation
C. Crop
D. Field

A. Land preparation

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_________ water requirement is the amount of water required in lowland rice production which is a function of the initial soil moisture and the physical properties of the soil.
A. Land preparation
B. Irrigation
C. Crop
D. Land soaking

D. Land soaking

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Spacing between irrigation laterals.
A. Ditch spacing
B. Lateral spacing
C. Horizontal spacing
D. Irrigation spacing

B. Lateral spacing

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Deep percolation of water beyond the root zone of plants, resulting in loss of salts or nutrients.
A. Vertical percolation
B. Root zone percolation
C. Leaching
D. Salt leaching

C. Leaching

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Canal with impermeable material (usually concrete) for channel stabilization and/or reduced seepage.
A. Line canal
B. Lined canal
C. Unlined canal
D. Impermeable canal

B. Lined canal

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Allowable pollutant-loading limit per unit of time, which the wastewater generator is permitted to discharge into any receiving body of water or land.
A. Pollutant limit
B. Loading limit
C. Allowable limit
D. Waste limit

B. Loading limit

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Portion of the pipe network between the mainline and the laterals.
A. Diversion pipe
B. Manifold
C. Main-lateral pipe
D. Reducer

B. Manifold

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Spillway which is not excavated such as natural draw, saddle or drainage way.
A. Surface spillway
B. Flood spillway
C. Natural spillway
D. Earth spillway

C. Natural spillway

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Constant flow depth along a longitudinal section of a channel under a uniform flow condition.
A. Critical depth
B. Constant depth
C. Laminar depth
D. Normal depth

D. Normal depth

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Maximum elevation of the water surface which can be attained by the spillway-type dam or reservoir without flow in the spillway.
A. Normal storage
B. Maximum storage
C. Critical elevation
D. Design depth

A. Normal storage

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Maximum elevation of the water surface which can be attained in an open channel without reaching the freeboard.
A. Normal storage
B. Maximum storage
C. Critical elevation
D. Design depth

D. Design depth

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In what condition is the open channel freeboard used for water conveyance?
A. Maximum flow
B. Emergency flow
C. Inundation
D. Rainy days

C. Inundation

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The primary purpose in limiting water flow not to go below minimum velocity.
A. Avoid percolation
B. Avoid sedimentation
C. Avoid critical depth
D. Optimize flow

B. Avoid sedimentation

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Open channel flow is water flow that is conveyed in such a manner that top surface is exposed to the atmosphere such as flow in canals, ditches, drainage channels, culverts, and pipes under _____ flow conditions
A. Full
B. Partially full
C. Normal
D. Critical

B. Partially full

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Part of the system that impounds the runoff.
A. Storage
B. Reservoir
C. Impounding
D. Runoff collector

B. Reservoir

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Slope at the downstream face of the embankment
A. Outside slope
B. Inside slope
C. Side slope
D. Soil gradient

A. Outside slope

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Ratio between reference evapotranspiration and water loss by evaporation from an open water surface of a pan.
A. Pan coefficient
B. Evaporation ratio
C. Reference pan ratio
D. ET ratio

A. Pan coefficient

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Rate of water loss by evaporation from an open water surface of a pan.
A. Surface evaporation
B. Sunken evaporation
C. Pan evaporation
D. Evaporation loss

C. Pan evaporation

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Vertical flow of water below the root zone which is affected by soil structure, texture, bulk density, mineralogy, organic matter content, salt type and concentration.
A. Leaching
B. Percolation
C. Infiltration
D. Seepage

B. Percolation

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Vertical flow of water to carry salts contained in water.
A. Leaching
B. Percolation
C. Infiltration
D. Seepage

A. Leaching

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Method to determine the rate of flow under laminar flow conditions through a unit cross sectional area of soil under unit hydraulic gradient.
A. Permeability test
B. Laminar test
C. Flow test
D. Hydraulic test

A. Permeability test

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The process by which the soil is removed from its natural place. A. Soil removal B. Runoff C. Soil erosion D. Leaching

C. Soil erosion

A kind of terrace which consists of a series of flattened areas. A. Broad-base terrace B. Bench terrace C. Conservation terrace D. Rice terrace

B. Bench terrace

The practice where legumes are plowed or incorporated into the soil. A. Legume incorporation B. Legume maturing C. Green manuring D. Manuring

C. Green manuring

Farming practice where plowing and harrowing are done along the contour. A. Contouring B. Strip cropping C. Crop row aligning D. Contour plowing

A. Contouring

The simplest method of determining soil erosion over a period of time. A. Catchment method B. Erometer method C. Plumb bob method D. Pin method

D. Pin method

Advance form of erosion. A. Rill erosion B. Gully erosion C. Sheet erosion D. Advanced erosion

B. Gully erosion

Dam which resists water flow of water by its weight. A. Resisting dam B. Buttress dam C. Gravity dam D. Arc dam

C. Gravity dam

Dam consisting of stones enclosed in cyclone wires which allows water passage. A. Gabion dam B. Stone dam C. Cyclone dam D. Interlink dam

A. Gabion dam

Material used to cover the soil to minimize evapotranspiration. A. Plastic B. Mulch C. Leaves D. Soil cover

B. Mulch

Geological formation shaped by the dissolution of a layer or layers of soluble bedrock, usually carbonate rocks such as limestone or dolomite. A. Geological layer B. Dissolved layer C. Soluble layer D. Karst topography

D. Karst topography

Scientific name of carabao grass commonly used in vegetated open channels. A. Glerisedia sepium B. Paspalum conjagatum C. Cyperus rotundos D. Leucaena leucocepala

B. Paspalum conjagatum

Philippine geographical constant for determining terrace vertical interval. A. 0.5 B. 0.8 C. 1 D. 1.5

A. 0.5

Constant for soil erodibility and cover conditions for erodible soil and poor cover. A. 0.5 B. 0.8 C. 1 D. 1.5

C. 1

Estimate the peak runoff rate in cubic meters per second from a 20-hectare drainage basin if rainfall depth for 6 hours reach 60 mm. Use typical runoff coefficient of 0.35. A. 2 B. 0.02 C. 0.2 D. 2.2

C. 0.2 Determining rainfall intensity I I = 60 mm/6 hours = 10 mm/hr Determining Peak Runoff Rate, q q = 0.0028CIA q = 0.0028(0.35)(10 mm/hr)(20 has) = 0.2 m3/s

Estimate the runoff volume in cubic meters from a 20-hectare drainage basin if rainfall depth for 6 hours reach 60 mm and duration of runoff is about 3 hours. Use typical runoff coefficient of 0.35. A. 1080 B. 1800 C. 1008 D. 8100

A. 1080 Determining rainfall intensity I I = 60 mm/6 hours = 10 mm/hr Determining Peak Runoff Rate, q q = 0.0028CIA q = 0.0028(0.35)(10 mm/hr)(20 has) = 0.2 m3/s Determining Total Runoff Volume, Q Q = 0.5 x Peak runoff rate x Duration Q = 0.5qT Q = 0.5(0.2 cu.m/s)(3 hrs x 3600 s/hr) Q = 1080 cubic meters

These results from the impact of water drops directly on soil particles or on thin water surfaces.

RAINDROP OR SPLASH EROSION

the upper part of the soil is washed away in a uniform thin layer from sloping lands, resulting to sheet or overland flow.

SHEET EROSION

The removal of soil by water from small but well – defined channels or streamlets. Rill is small enough to be easily removed by normal tillage operations. It is the form on which most soil erosion occurs.

RILL EROSION

Is an advance form of rill erosion. It produces channels larger than rills that cannot be erased by tillage.

GULLY EROSION

Consist of soil removal from banks of streams or rivers. The water cuts the lower banks causing the upper parts to fall.

STEAM CHANNEL EROSION

Are channel sodded with grasses, which absorbs the energy of run – off.

CONSTRUCTION OF VEGETATED WATERWAYS

Is a method of erosion control accomplished by constructing board channel or benches across the slope. Terraces control erosion by reducing the slope length.

TERRACING

Consist of a series of flattened areas that are converted steep slope of 20 to 30 % to a series of level benches.

BENCH TERRACE

The primary purpose of this type of terrace is to remove excess water to minimize erosion. The intercepted runoff is conducted to a safe outlet at a lower velocity

GRADED OR CHANNEL TYPE TERRACE

The primary purpose for this type of terrace is moisture conservation. It intercepts and detains runoff to be stored in the soil profile.

LEVEL OR RIDGE-TYPE TERRACE

Field operation such as plowing, harrowing, planting, cultivating, and harvesting are performed approximately on the contour.

CONTOURTING OR CONTOUR FRAMING

Is the process of growing alternate strips of different crops in the same field.

STRIP CROPPING

The layout and tillage are closely to the exact contour and with the crops following a definite rotational sequence.

CONTOUR STRIP CROPPING

Strip of uniform width is placed across the general slope.

FIELD STRIP CROPPING

Strips of closely growing plants, usually grass or legumes, are laid to out between contour strips of crops in regular rotations.

BUFFER STRIP CROPPING

A practice where adjoining farms operate as a single unit.

COMPACT FARMING

Planting closely growing crops such as grass and legumes.

COVER CROPPING

The systematic planting of different crops in succession. Generally, a leguminous crop should follow a grain crop; a deep-rooted crop should follow a shallow rooted crop.

CROP ROTATION OR RELAY CROPPING

A practice where legumes are plowed and incorporated with the soil during the flowering stage to improve the soil structure, increase the filtration capacity and provide nutrients for plants.

GREEN MANURING

Application of the tillage necessary to produce crops. Most parts of the field are left undisturbed and compact to give greater resistance for the field against erosion

MINIMUM TILLAGE

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

MULTIPLE CROPPING OR MIXED CROPPING

Is a multiple cropping system where different crops are grown at alternative rows.

INTERCROPPING

Aims to break –up hard pans, either natural ones or those developed by continuous plowing at the same depth, to improve infiltration.

SUBSOILING OR SUB – SURFACE TILLAGE

An instrument to measure the depth and intensity of rain falling or a flat surface.

RAIN GAGE

Refers to the depth of rainfall over an area per unit time.

RAINFALL INTENSITY

Type of rain gage which measures rain depth and intensity.

RECORDING RAIN GAGE

Type of rain gage which measures rain depth only. Rain gages of this type are generally vertical, cylindrical containers with top opening 203mm(8 in.) in diameter. The water is funneled into an inner cylinder one-tenth of the cross section of the catch area or collector.

NON – RECORDING RAIN GAGE

The average periods of time, which the depth of rainfall for a given duration will be equaled or exceeded once on the average.

RETURN PERIOD OR RECURRENCE INTERVAL

This can be computed by summing all the rainfall observations divided by the number of observations

AVERAGE DEPTH OR ARITHMETIC

Location of the rain gages plotted on a map of the watershed and straight lines are drowning between the rain gages. Perpendicular bisectors are then constructed on these connecting lines such that the bisectors form on an enclosed referred to as Thiessen polygon. The rain recorded is then considered to represent the precipitation within the appropriate polygon area.

THIESSENS METHOD

This involves the plotting of isohyets or lines of equal rainfall.

ISOHYETAL METHOD

Is that portion of the precipitation that makes its way forward stream channels, lakes or oceans as surface flow.

RUNOFF

Is defined as the application of water to soil for the purpose of supplying the moisture essential for plant growth.

IRRIGATION

Refers to the weight of a unit volume of dry soil in its natural structural condition.

BULK DENSITY

Is the ratio of the weight of a given volume of dry soil, airspace included, to the weight of an equal volume of water. It is also the ratio of the bulk density to the density of water.

APPARENT SPECIFIC GRAVITY

Is the weight per unit volume of the soil particle.

PARTICLE DENSITY

Is the ratio of the density of a single soil particle to the density of water.

REAL SPECIFIC GRAVITY

Is a thin film of water on the surface of the soil grains and is not capable of significant movement by the action of gravity or capillary forces.

HYGROSCOPIC WATER

Is that parts in excess of the hydroscopic water, which exist in the pore space of the soil and is retained against the force of gravity

CAPILLARY WATER

Water that moves downward freely by the action of gravity.

GRAVITATIONAL WATER

Is the moisture content of the soil when the gravitational water has been removed. It is usually determined two days after irrigation or heavy rainfall.

FIELD CAPACITY

The soil moisture content when plants permanently wilt. A plant is considered to be permanently wilted when it will not revive if placed in a saturated Condition

PERMANENT WILTING POINT OR WILTING COEFFICIENT

The range in moisture content between filed capacity and wilting point. It represents the amount of water that can be retained in the soil for the use by the crop.

AVAILABLE MOISTURE

Refers to the percentage of the available moisture to which the moisture content is allowed to reach before the next irrigation is applied.

ALLOWABLE DEFICIT

Determines the depth of soil necessary to be welted during irrigation. Water application beyond the root zone result to water loss due to deep percolation while shallow application inhibits full development of the root system.

ROOTZONE DEPTH

Refers to the number of days between two irrigation applications. It is also the number of days after irrigation when the moisture content reaches the allowable depletion level.

IRRIGATION INTERVAL OR FREQUENCY

The number of hour’s irrigation water is applied. It is influence by the filtration capacity of the soil.

IRRIGATION PERIOD

Refers to the sum of the water requirement and losses due to the inefficiency of the irrigation system.

NET WATER REQUIREMENT OR NET APPLICATION DEPTH

Water content of the soil is measured by oven drying the soil samples 150OC until there is no further change in weight. Time of drying is at least 24 hours.

GRAVIMETRIC METHOD

This rapid means of onsite moisture measurement.

NEUTRON SCATTERING

Is an instrument used to describe the moisture status of the soil in terms of its suction.

TENSIOMETER

This is a method employed only by the experienced irrigators. The irrigators observe the moisture of the soil by pressing a soil sample with his fingers.

FEEL AND APPEARANCE METHOD

These are used in places where the natural ground to where the canal will be laid out is very steep. If the canal profile follows the canal ground, the water velocity could be very high. The energy of the following stream is dissipated in the stilling basin or apron of drops.

DROPS OR DROPS SPILLWAYS

These are structures which are used to convey water down relatively steep hills which would require many drops closely spaced to control water velocity.

CHUTES

Is an elevated section of an irrigation canal. It is used for crossing natural depressions like creeks or rivers.

FLUME

Conveys water over the ditch bank into the field or furrow.

SIPHON TUBE

These are pipelines build on or near the ground surface. This structure conveys water across wide depressions.

INVERTED SIPHONS

This is done introducing water and letting it spread over the area to be irrigates. Water is applied from ditches without any levees to guide its flows or restrict its movement. This irrigation method is suited in place where water is abundant and inexpensive

UNCONTROLLED OR WILD FLOODING

Is done by subdividing the field into a series of strips, 5 to 20 meters wide and 75 to 100 meters long by levees or borders. Two adjacent borders guide advancing water. Strips are usually oriented to run down the predominant slope through some are built on the contour.

BORDER STRIP FLOODING

Consist of supplying large flow into relatively level plots surrounded by levees or dikes. This method is suited to prevent high percolation losses in areas with highly permeable soils.

LEVEL BORDER OR CHECK FLOODING

Like the level border, the area irrigated by this method is surrounded by levees. It is useful on fine texture soils with low permeability where it is necessary to maintain standing water to secure adequate penetration.

BASIN FLOODING

Requires the forming of small channel known as furrows where the irrigation water runs through. Irrigation by furrow wets only a portion of the ground surface, thus, reducing evaporation.

FURROW IRRIGATION

It is a variation of the furrow method and makes use of small and shallow furrow of rills called corrugation.

CORRUGATION IRRIGATION

Application of irrigation water is done in much the same way as rain. With this method, not only the soil is wetted but also the stem and leaves of the plants

OVERHEAD IRRIGATION

is the simplest overhead irrigation equipment commonly used in backyard gardening. It is provided with a thin cylinder stem with a perforated part on the end to allow rainfall simulation

WATERING CAN

This is done in place where there is a piped water system. A hosepipe is connected to an outlet or faucet, which conveys water to the crops.

HOSE PIPE

Consist of applying water to the surface of the soil in form of spray, which closely resembles that of rain. The flow water under pressure through small opening or nozzles produces the spray.

SPRINKLER IRRIGATION

Is a method of applying water directly to the soil near the plant through a network of small diameter pipes. The pipes provided with low flow rate outlets called emitters of drippers.

DRIP OR TRICKLE IRRIGATION

The depth of water in mm or inches to be removed in a 24-hour period from the drainage area, (in mm/day or in/say)

DRAINAGE COEFFICIENT

Specific property of soil is measure of the readiness with which the soil transmits water. Permeability is a velocity and for agricultural purposes can be conveniently expressed either in inches/hour or cm/hour.

Permeability

The downward movement of water into the soil through the soil surface, and the rate is generally expressed in in/hr or mm/hr.

Infiltration

Refers to the passage of soil water through the plant system, principally the leaves and its vaporization into the atmosphere.

Transpiration

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

Stilling Basin

a principle of English Common Law, which recognizes the right of riparian owner to make reasonable use of the stream flow provided the water, is used on riparian land.

Riparian Right

is that which is contiguous to a stream or body of water surface.

Riparian Land

type of drain whereby channels are produced by a tractor – drawn shaped metal in a subsoil without a trench from the surface.

Mole drain

consist of growing alternate strips of clean cultivated and close – growing crops in the same field.

Strip Cropping

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

Multiple Cropping or mixed cropping

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

Relay Cropping

Is a gate placed across a stream from which it is desired to divert water. The function of the check gate is analogous to that of the dam of the diversion weir or the rivers at the heads of canal systems.

Check gates

Used to divert from a project canal into the farm delivery systems or from a man canal into lateral canals.

Head gates

Specially shaped and stabilized channel section, which may also be used to measure flow and is generally less inclined to catch floating debris and sediments than a weir.

Flume

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

Culvert

The ratio of depth of direct run – off to depth precipitation producing the runoff over a drainage area.

Run-off coefficient

An irrigation method which necessitates the welting of only part of the surface (from ½ to 1/5) thus reducing evaporation losses, lessening the pudding of heavy soils, and making it possible to cultivate the soil sooner after irrigation.

Furrow Irrigation

An irrigation that makes use of small, shallow furrows.

Corrugation

A structure for passing out water not needed for storage or diversion.

Spillway

Any open channel or closed – conduit that conveys water.

Waterway

Static head plus pump, pipe and discharge head losses plus velocity head.

Total Dynamic Head

Defined as the sum of the volumes of water used by the vegetation growth of a given area for transpiration and building of plant tissues plus that evaporated from the adjacent ground or intercepted precipitation on the area in any specified time divided by the given area.

Consumptive use

The suitability of land for cropping or some of her use and the degree or intensity of land special soil and water conservation practices required for such use.

Land capacity

A horizontal projection of an area whose boundary follows ridges and summits from which a lake or stream receives surface water originating as precipitation.

Watershed

Downward movement of water within the soil.

Percolation

The application of water to soil the purpose of supplying the moisture essential for the plant growth.

Irrigation

The removal of excess water from agricultural land by means of open or covered drains.

Drainage

Is the moisture content in the soil per unit depth, which is usually expressed in inches per foot or mm per meter.

Moisture Capacity

The flow of liquid through porous media, the loss of water from irrigation canals.

Seepage

Can be estimated by dividing the field capacity by a factor varying from 2.0 to 2.4 depending upon the amount of silt in the soil.

Wilting Percentage

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

Soil texture

Quantity of water in the soil that is available for plant use, as limited by the field capacity, and the permanent wilting percentage.

Available soil moisture

an irrigation method formed by building longitudinal levees approximately parallel to the contour and connecting them at desirable places with levees at right angles.

Check contour

Application of water in small basins to retain the water and facilitate penetration. The basin may be formed in furrows or maybe several feet in dimensions.

Basin method of irrigation

Quantity of irrigation water, exclusive of precipitation, required by crops for their normal growth under field condition.

Irrigation requirement

A natural body composed of mineral and organic material on the surface of the earth in which plants growth.

Soil

An irrigation structure that conveys water from a higher to a lower level, maybe inclined or vertical.

Drop structure

Physical property of rock or soil material that defines degree to which they contain interstices, expressed as ratio of volume or interstices to the total volume of rock or earthen materials.

Porosity

The ratio of the cross sectional area of the flow in an open channel to the wetted perimeter of the flow in contact with the channel.

Hydraulic Radius

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

Contour line

The application of irrigation water with dissolved fertilizer to the field.

Fertigation

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

Soil Conservation

The wearing away or detachment of soil particles from earth surface by either wind or water.

Soil erosion

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

Graded terrace

In a system of moist air, the ratio of the mass of water vapor present to the volume occupied by the mixture.

Absolute Humidity

Erosion increased by human agency to beyond the normal geologic rate.

Accelerated erosion

The volume of water required covering one acre to a depth of one foot, hence, 43, 560 cubic feet.

Acre-foot

A thermodynamic change of state of a system in which there is no transfer of heat or mass across the boundaries of the system

Adiabatic process

In general, climatology as applied to the effect of climate on crops.

Agricultural climatology

The mixture of gases comprising the earth’s atmosphere.

Air The percent by volume of those gases found in relatively constant amount in dry air is as follows: Nitrogen (N2) 78.084 % Oxygen (O2 ) 20.946 Argon (A) 0.934 Carbon Dioxide (CO2) 0.033 Neon (Ne) 0.0018 Helium (He) 0.000524 Methane (CH4) 0.0002 Krypton (Kr) 0.000114 Hydrogen (H2) 0.00005 Nitrous Oxide (N2O) 0.00005 Xenon (Xe) 0.0000087

A widespread body of air, the properties of which can be identified as having been established while that air was situated over a particular region of the earth’s surface.

Air mass

An imaginary body of air, which may be assigned any or all of the basis dynamic and thermodynamic properties of air.

Air parcel

An expression of the amount of electromagnetic radiation reflected by a body to the amount incident upon it

Air pocket

The microscopic particles in the atmosphere which serve as condensation nuclei for droplet growth during the rapid adiabatic expansion.

Aitken nuclei

the ratio of the amount of electromagnetic radiation reflected by a body to the amount incident upon it.

Albedo

a geologic formation which may contain large quantities of water, but which does not permit movement of water at rates sufficient to support larges springs or justify the economic development of wells.

Aquiclude

a geologic formation that transmit water in sufficient quantities to support the economic development of wells.

Aquifer

A geologic formation that has no interconnected openings and hence cannot transmit or receive water.

Aquifuge

generally, any extremely dry climate.

Arid climate

also called mean, average which is one of the accepted measures of central tendencies

Arithmetic mean

the envelope of air surrounding the earth and bound to it by the earth’s gravitational attraction exerted upon it by the column of air directly above the point in question.

Atmosphere

the pressure exerted by the atmosphere as a consequence of gravitational attraction exerted upon it by the column of air directly above the point in question.

Atmospheric pressure

a mass of snow moving rapidly down a mountain slope

avalanche

that transition zone between earth and atmosphere within which most of terrestrial life are commonly found.

Biosphere

a hypothetical body which absorbs all of the electromagnetic radiation striking it.

Black body

the temperature at which the equilibrium vapor pressure between a liquid and its vapor is equal to the external pressure on the liquid.

Boiling point

the ratio of the universal gas constant to Avogadro’s number equal to 1.3804 x 10-16 ergs per degree Kelvin.

Boltzman's constant

A law describing the relationship of the horizontal wind direction in the atmosphere to the pressure distribution. If one stands with his back to the wind, the pressure to the left is lower than to the right in the Northern Hemisphere.

Buys Ballot

A unit of heat defined as the amount of heat required to raise the temperature of one gram of water through one degree centigrade.

Calorie

the phenomena resulting from the operation of surface tension on liquids in narrow tube.

Capillarity

a sequence of atomic nuclear reactions and spontaneous radioactive decays which serves to convert matter into energy in the form of radiation and high-speed particles.

Carbon cycle

a heavy, colorless gas of chemical symbol CO2.

Carbon dioxide

a temperature scale with the ice point at 0 degree and the boiling point of water at 100 degrees. Conversation to the Fahrenheit temperature scale is given by the formula.

Celsius temperature scale

the apparent force in a rotating system, deflecting masses radically outward from the axis of rotation.

Centrifugal Force

the vaguely defined region of the upper atmosphere in which photochemical reactions take place.

Chemosphere

a statistical significance test based upon the frequency of occurrence.

Chi-square Test

the flow or motion of a fluid or through a given area or volume.

Circulation

the differential equation relating pressure to temperature in given system in which two phases of a substance is in equilibrium.

Clapeyron – Classius equation

the long term of weather. It is the statistical collective of weather conditions.

Climate

the type of observation which includes the evaluation of one more of the following: maximum – minimum temperature and total precipitation and may also include the description of weather such as cloudy, clear etc. Observations are done at least once daily.

Climatological observation

the scientific study of climate.

Climatology

a hydrometer consisting of a visible aggregate of minute water and or ice particles in the atmosphere above the earth’s surface

Cloud

any technique carried out with the intent of adding to a cloud certain particle that will alter the natural development of cloud.

Cloud seeding

the merging of two water drops into a single larger drop

Coalescence

the time required for water to travel from the most remote point of a river basin to the basin outlet.

Concentration

the physical process by which a vapor becomes liquid or solid.

Condensation

the transfer of energy within and through a conductor by means of internal particle or molecular activity.

Conduction

the principle that the total energy of an isolated system remains constant.

Conservation of energy

The principle that states that mass cannot be created nor destroyed but only transferred from one volume to another. It is generally expressed in the form of continuity equation.

Conservation of mass

in general, mass motions within a fluid resulting in transport and mixing of the properties of the fluid.

Convection

in a specified stream channel, the water depth at which the specific energy is the minimum for the given flow rate.

Critical depth

the empirical generalization that for many so called perfect gases, a mixture of these gases will have a pressure equal to the sum of the partial pressures that each of these gases, mixture of these gases will have a pressure equal to the sum of the partial pressures of these gases would have as sole component with the same volume and temperature, provided there is no chemical interaction.

Dalton's Law

Generally, a measure of the departure of the mean daily temperature from a given standard.

Degree-day

the ratio of the mass of any substance to the volume occupied by it (usually expressed in grams per cubic centimeter).

Density

in general, point or area of locally lower elevation in a particular surface. In meteorology an area of low pressure.

Depression

the temperature at which the air becomes saturated when air is cooled under constant pressure and with constant water vapor content.

Dew point temperature

thermodynamic change of state of a system in which there is transfer of heat across the boundaries of a system.

Diabatic process

the process by which the direction of radiation is changed so it spreads into the geometric shadow region of an opaque or refractive object that lies in a radiation field.

Diffraction

In meteorology, the exchange of fluid particles between region spaces.

Diffusion

The rate of flow of water past a point in a stream, expressed as volume per unit time.

Discharge

(Also called equatorial calms). A nautical term for the equatorial trough.

Doldrums

(Also called catchment area). The size of the area comprising a watershed or river basin.

Drainage area

Very small, numerous and uniformly dispersed water drops that may appear to float while following air currents.

Drizzle

a period of abnormally dry weather sufficiently prolonged for the lack of water to cause a serious hydrologic imbalance.

Drought

A special lapse rate of temperature, defined as the rate of decrease of temperature with height of a parcel air lifted adiabatically through an atmosphere in hydrostatic equilibrium, the value being equal to 10 degrees Celsius per kilometer or 5.4 degrees Fahrenheit per thousand feet.

Dry – adiabatic lapse rate

in certain types of climates, an annually recurring period of one or more months during which precipitation is at a minimum for that region.

Dry season

Loosely, a period of abnormally dry weather.

Dry spell

That part of the precipitable water which, in theory, can actually fall as precipitation.

Effective precipitable water

That part of the precipitation that reaches stream channels as runoff

Effective precipitation

The layer of transition between the surface boundary layer where the shearing stress is constant, and the free atmosphere, where the atmosphere is treated as an ideal fluid in geostrophic equilibrium.

Ekman Layer

The ratio of the emittance of a given surface at a specified wavelength and emitting temperature to the emittance of an ideal black body at the same wavelength and temperature.

Emissivity

in meteorology, the mixing of environment air into a pre – existing organized air current so that the environmental becomes part of the current.

Entrainment

The rate of decrease of temperature with elevation. ∆T/∆z

Environmental lapse rate

geographically, the imaginary great circle of latitude zero degree on the earth’s surface.

Equator

the movement of the soil or rock from one point to another by the action of the sea, running water, precipitation or wind.

Erosion

(Also called vaporization). The physical process by which liquid or solid is transformed to the gaseous state.

Evaporation

a hydrometer consisting of a visible aggregate of minute water droplets suspended in the atmosphere near the earth’s surface.

Fog

a unit of illuminance equal to one lumen per square foot

Food-candle

a statement of expected future occurrences, that which is predicted.

Forecast

dark lines in the absorption spectrum of solar radiation.

Fraunhofer lines

that portion of the earth’s atmosphere above the planetary boundary layer in which the effect of the earth’s the air is friction on the air motion is negligible, and in which the air is treated dynamically as an ideal fluid.

Free atmosphere

the phase transition of a substance is passing from the liquid to the solid state.

Freezing

the rate of recurrence of an event in periodic motion

Frequency

the mechanical resistive force offered by one medium or body to the relative motion of another medium or body in contact with the first.

Friction

in meteorology, the interface or transition zone between two air masses of different density.

Front

the initial formation of a front.

Frontogenesis

the phase transition of a substance passing from solid to the liquid state; melting

Fusion

In its broadest sense, the complete statistical description of atmospheric motions over the earth

General circulation

received by a unit horizontal surface.

Global radiation

a hypothetical “body” which absorbs some constant fraction, between zero and one, of all electromagnetic radiation incidents upon it.

Gray body

the heating effect exerted by the atmosphere upon the earth by virtue of the fact that the atmosphere absorbs and remits infrared radiation.

Greenhouse effect

generally, the period of the year during which the temperature of cultivated vegetation remains sufficiently high to allow plants growth.

Growing season

a form of energy transferred between systems by virtue of a difference in temperature and existing only in the process of energy transformation.

Heat

the equilibrium that exists on the average between the radiation received by the earth and atmosphere from the sun and that emitted by the earth and atmosphere.

Heat balance

the transfer or exchange of heat by radiation, conduction or convection in a fluid and or between the fluid and it surroundings.

Heat transfer

one of several lines or planes used as reference for observation and measurement relative to a given location on the surface of the earth generally referred to as horizontal direction.

Horizon

generally, some measure of water vapor content of air.

humidity

the slope of the profile of the static level for a hydraulic system. In open channel flow, the hydraulic gradient is the slope of the water surface taken parallel to the flow.

Hydraulic gradient

a graphical representation of stage or discharge at a point on a stream as a function of time.

Hydrograph

The composite picture, including change of state and vertical and horizontal transport of the interchange of water substance between the earth, the atmosphere and seas.

Hydrologic cycle

the scientific study of the waters of the earth, especially with relation to the effects of precipitation and evaporation upon the occurrence and character of water in streams, lakes and or below the land surface.

Hydrology

any product of condensation or sublimation of atmospheric water vapor whether formed in the free atmospheric of at the earth’s surface.

Hydrometer

that part of meteorology of direct concern to hydrologic problems, particularly to flood control hydroelectric power, irrigation and similar fields of engineering and water resources.

Hydrometeorology

a colloidal system in which the dispersion medium is water.

Hydrosol

The water portion of the earth.

Hydrosphere

a map chart displaying temporal or aerial distribution of precipitation.

Hyetograph

a recording instrument combining on one record, the variation of temperature and humidity as a function of time.

Hygrothermograph

any one of macroscopic crystalline forms in which ice appears, including hexagonal columns, ice needles, etc.

Ice crystal

the total luminous flux received on a unit area of a given real or imaginary surface, expressed in such units as the foot – candle, lux, or phot. Illuminance is analogous to irradiant.

Illuminance

the passage of water through the soil surface into the soil or the quantity of water entering the soil.

Infiltration

(Also called long-wave radiation). Electromagnetic radiation lying in the wavelength interval from about 0.8 micron to an indefinite upper boundary sometimes set at 1000 microns.

Infrared radiation

(Contracted from incoming solar radiation). In general, solar radiation received at the earth’s surface.

Insulation

a property of the steady state of a system such that certain disturbance or perturbations introduced into the steady state will increase in magnitude

Instability

(or thermometer shelter) A box-like structure designed to protect certain meteorological instruments from exposure to direct sunshine, precipitation and condensation, while at the same time providing ventilation.

Instrument shelter

the process by which precipitation is caught and retained on vegetation or structures and subsequently evaporated without reaching the ground.

Interception

(Also called equatorial convergence zone). The axis or portion thereof, of the broad trade wind current of the tropics. The axis is the dividing line between the southeast trades as the northeast trades

Intertropical convergence zone

in meteorology, a departure from the usual decreases or increases altitude of the value of an atmospheric property.

Inversion

the atmosphere shell characterized by a high ion density its base is at about 70 or 80 km and it extends to an indefinite height.

Ionosphere

a line of equal change in atmosphere pressure during a specified time interval.

Isallobars

Of equal or constant entropy, (or in meteorology, potential temperature), with respect to either space or time

Isentropic

a line of equal or constant pressure; an isopleth. In meteorology, it most often refers to a line drawn through all points of equal atmospheric pressure along a given reference surface.

Isobar

(sometimes called fathom curve). A contour of equal depth in a body of water

Isobaths

a line or surface showing the depths in oceans or lakes at which point have the same temperature.

Isobathythem

a line in a chart connecting points having the same time of occurrence of a particular phenomenon. In meteorology, the past position of fronts, instability lines, isotherms etc.

Isochrone

a line connecting points having the same vertical direction of a particular vector quantity.

Isocline

a line drawn through all points on the earth’s surface having the same magnetic inclination

Isoclinic line

a line or surface showing the depths in the ground at which points have the same temperature. Isogeotherms are often drawn against coordinates of the time and depth to represent the diurnal or annual variation of soil temperature.

Isogeotherms

in meteorology, isogons are usually drawn the velocity vector as an aid in constructing streamlines for a wind field.

Isogons

of equal or constant salinity.

Isohaline

a line drawn through geographical points recording equal amounts of precipitation during a given period for a particular storm.

Isohyets

a line drawn through all points on a map having the same amount of cloudiness.

Isoneph

a line of equal or constant specific volume

Isopycnic

a line of equal magnitude of vertical wind shear.

Isoshear

a line of equal or constant temperature.

Isostere

(also called isovel). A line in a given surface connecting points with equal wind speed.

Isotach

a line of equal or constant temperature.

Isotherm

relatively strong wings concentrated within a narrow stream in the atmosphere.

Jet stream

a unit of energy equal to 10 ergs or 0.2399 calorie

Joule

any wind blowing down an incline, the opposite of anabatic wind. If the wind is warm, it is called a foehn; if cold, it may be a fall wind, or a gravity wind such as a mountain wind.

Katabatic wind

of, or pertaining to, a decrease in atmosphere pressure.

Katallobaric

an absolute temperature scale independent of the thermodynamic properties of the working substance. The ice point in the Kelvin scale in 273.160 K

Kelvin temperature scale

the energy which a body posses as a consequence of its motion, defined a one- half the product of its mass and the square of its speed. ½ mv2.

Kinetic energy

The radiation law which state that a given temperature the ratio of the emissivity to the absorptivity for a given wavelength is the same for all bodies and is equal to the emissivity of an ideal black body at that temperature and wavelength.

Kirchoff’s Law

a law in radiometry which state that at a given temperature of the ratio of emissivity to the absorptivity for a given wavelength is the same for all bodies angle between the normal to the surface and the direction of the radiation.

Lambert’s law

the complete cycle of diurnal local winds occurring on seacoasts due to differences in surface temperature of land and sea.

Land and sea breeze

a coastal breeze blowing in the land to sea, caused by the temperature difference when the sea surface is warmer than the adjacent land. Therefore, it usually blows by the night and alternates with a see breeze, which blows in the opposite direction by day

Land breeze

a unit of energy per unit area commonly employed in radiation theory; equal to one – gram calorie per square centimeter.

Langley

a curve showing the variation of temperature with height in the free air.

Lapse line

the decrease of an atmospheric variable with height, the variable being temperature, unless otherwise specified.

Lapse rate

that portion of the atmosphere from the earth’s surface to the Tropopause, i.e., the lowest 10 to 20 km of the atmosphere.

Troposphere

the boundary between the troposphere and stratosphere, usually characterized by an abrupt change of lapse rate.

Tropopause

The system, occupying most of the tropics, which blows from the subtropical highs toward the equatorial trough.

Trade winds

The water that reaches streams by traveling over the surface of the soil.

Surface runoff

the atmosphere shell above the troposphere and below the mesosphere.

Stratosphere

Relates the wavelength of maximum intensity emitted by a black body to its absolute temperature.

Wien’s Law

general term for the class of actinometers, which measure the intensity of direct solar radiation.

pyrheliometer

general name for the class of actinometers, which measure the combined intensity of incoming direct solar radiation and diffuse, sky radiation.

Pyranometer

generally, the amount of moisture which, if available would be removed from a given land area by evapotranspiration.

Potential evapotranspiration

same as zone of saturation

Phreatic zone

Same as water table.

Phreatic surface

the point on the earth’s surface, which is nearest the sun. At present, the earth reaches this point on about January 1.

Perihelion

Water flowing over the ground surface toward a channel. Upon reaching the channel, it is called surface runoff.

Overland flow

precipitation that results from the lifting of moist air over an Orographic barrier such as a mountain range.

Orographic precipitation

the lifting of an air current caused by its passage up and over mountains.

Orographic Lifting

the outer, solid portion of the earth; the crust of the earth.

Lithosphere

Soil and Water Conservation Engineering Flashcards

(313 cards)