PART 2: HYDROLOGY AND SWE GLOSSARY OF TERMS Flashcards
A kind of well that has been treated to
eliminate the potential for contamination of aquifer.
abandoned well
Dike and drainage structure protecting
marshlands; Outlet structure with flap gate which permits outflow of
fresh water, but prevents inflow of tidal salt water.
Aboiteaux
Erosion which is much more rapid
than normal, natural, or geological erosion, primarily as a result of the
influence of the activities of man or in some cases, of animals.
Accelerated Erosion
The build-up or increase of one or more
constituents in the soil at a given position as a result of translocation.
The build-up may be a residue due to the translocation of material out of
the horizon or may be due to an addition of material.
Accumulation
Is a soil with a pH below 7.0.
acid soil
Refers to the volume of water that would
cover one acre to a depth of one foot
acre-foot
Composting system using controlled
aeration from a series of perforated pipes running underneath each pile
and connected to a pump that draws or blows air through the piles.
Aerated Static Pile
The decay organic matter by
microorganisms in the presence of oxygen.
aerobic decomposition
A structural cross section resembling the capital
letter A, which consists of two rigid members together at the bottom and
usually braced in the middle.
A-frame
Is defined as the quantity of air in
the soil which remains after the soil has been saturated with water to the
point of absolute water capacity.
air capacity of soils
Upward movement of air through the
soil during downward flow (percolation) water.
Air Counter Flow
Renewal of soil by air diffusion.
air drainage
Device that releases air from a pipeline
automatically without permitting loss of water.
air relief valve
An outlet valve attached to the top of a riser
with an opening equal in diameter to the inside diameter of the riser pipe
and an adjustable lid or cover to control the flow of water.
Alfalfa Valve
Soils not having the same physical
properties when the direction of measurement is changed.
Anisotropic Soils
Flow
rate of water passing through a unit cross section of porous media.
Apparent Flow Velocity
Rate that water is applied to a given
area. Usually expressed in units of depth per time;
Application Rate
Floor lining extending downstream from a
hydraulic structure to protect the structure from erosion and scour;
Apron
Underground geologic formation that neither
yields nor allows the passage of an appreciable quantity of water,
although it may be saturated with water itself
aquiclude
An underground formation that contains sufficient
saturated permeable material to yield significant quantities of water; A
geologic formation that hold and yield useable amount of water.
Aquifer
Underground geologic formation that is slightly
permeable and yields inappreciable amounts of water when compared to
an aquifer.
aquitard
Curved masonry concrete dam, convex
upstream, that depends to arch action for its stability.
arched dam
Climate characterized by low rainfall and
high evaporation potential.
arid climate
Aquifer that contains water under
pressure as a result of hydrostatic head.
artesian aquifer
is
the ratio of the length of the longer sides to the length of the shorter
sides.
aspect ratio
Natural ability of soil, air or water
to accept and/or degrade potential pollutants without harmful effects to
the environment.
Assimilative Capacity
Any pump designed to perform a service
to the main pump or power unit, such as a cooling water or a standby
pump to supplement the system for peaking requirements.
Auxiliary Pump
Dam spillway built to carry runoff in
excess of that carried by the principal spillway. This is sometimes called
emergency spillway.
Auxiliary Spillway
The portion of water in a soil that
can be readily absorbed by plant roots. It is the amount of water
released between in situ field capacity and the permanent wilting point.
Available Soil Water
The weight percentage of
water which a soil can store in a form available to plants. It is equal to
the moisture content at field capacity minus that at the wilting point.
available water capacity
Type of pump which develop most of
the suction and discharge head by propelling or lifting action of the
impeller vanes on the water; A rotary pump that develops head mostly
by the propelling or lifting action of the vanes on water, commonly
referred to as a propeller pump.
axial flow pump
The horizontal angle in degrees measured from
due south in the northern hemisphere (due north in the southern
hemisphere)
azimuth
The replacement of the
excavated material after drain replacement and blinding, or envelope
installation.
Backfilling (Drainage)
Land area on the downhill side of a terrace
ridge or earth embankment.
Backslope
Water leaving a stream channel during
rising stages of stream flow, most of which returns to stream flow during
falling stages
bank storage
(1) The cross-sectional area of the base of a
cone penetrometer, (2) Contact area of a dam with original surface.
base area
Circle of an involute cylindrical gear, the
“base circle” of the involutes forming the tooth profile.
base circle
Water in a stream that results from groundwater inflow i.e., that which is not affected by surface inflow.
baseflow
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.
basic hydrograph
Irrigation by flooding areas of level land
surrounded by dikes.
basin irrigation
A surface drainage method accomplished by
plowing land to form a series of low narrow ridges separated by parallel
dead furrows.
bedding
The acute angle of a V-groove in the
bottom of a trench for support of pipe drains.
bedding angle
Coarse sediment or material moving on or
near the bottom of a flowing channel by rolling, sliding or bouncing.
bed load
A water conducting channel built on
constructed terraces along hillsides or around mountain slopes when the
ground is too rough, steep, or rocky to permit an excavated canal.
bench flume
Level terraces built in stair-step fashion
with a level top and a steep, vertical embankment between successive
terraces, used to improve distribution of rainfall or irrigation water.
bench terrace
Strip or area of land, usually level, between the
edge of spoil bank and edge of a ditch or canal.
berm
A structural or
nonstructural method, activity, maintenance procedure, or other
management practice used singularly or in combination to reduce
nonpoint source inputs to receiving waters in order to achieve water
quality protection goals.
Best Management Practice (BMP)
Breaking down of natural or synthetic
organic materials by microorganisms in soils, natural bodies of water,
wastewater treatment systems.
biodegradation
A rupture in a pip drain usually attributed to
hydraulic pressure from within the line and resulting in displacement of
pipe and in washout of supporting and covering earth materials. Also
“break troughs” or ruptures in embankments caused by piping.
blowout
A type of terrace constructed so
that crops can be planted and machinery safely operated on the entire
cross section.
Broadbase Terrace
Weir for water measurement having
a rounded or wide crest in the direction of the stream.
Broad-Crested Weir
The mass of dry soil per unit bulk
volume.
bulk density
Vegetative cover over the land surface of a
catchment area.
canopy
Entrance to a closed conduit that has been
covered or shielded to induce priming aluminum submergence.
canopy inlet
A zone in the soil just above the water
table that remains saturated or almost
unsaturated.
capillary fringe
Is
that amount of water that is capable of
movement after the soil has drained. It
is held by adhesion and surface
tension as films around particles and in
the finer pore spaces.
capillary moisture
(Preferred term is Soil-water
pressure).
capillary pressure
Height water will rise by
surface tension above a free water surface in the soil, expressed as
length unit of water. Sometimes called “capillary rise.”
Capillary Pressure Head
Is held by the surface tension forces as
a continuous film around the particles and in the capillary spaces.
CAPILLARY WATER
An irrigation pipeline riser
extending above the ground, with a water tight cap over its top and outlet
gates on its sides slightly above the ground surface.
capped riser or pot
A sequence of atomic nuclear reaction
sand spontaneous radioactive decays which serves to convert matter
into energy in the form f radiation and high speed particles.
carbon cycle
An excavator that uses a chain with
cutters attached to cut or remove, and deposit spoil to the side of the
trench or on to a discharge conveyor.
Chain Trencher
A structure to control water depth in a canal, ditch
or irrigated field.
Check
Small barrier constructed in a gully or other
small watercourse to decrease flow velocity, minimize channel scour,
and promote deposition of sediment.
check Dam
Lined channel constructed with a steep
slope to convey water to lower level without erosion.
chute spillway
Man-made reservoir or receptable for holding
water or other liquids
cistern
The water table of
piezometric surface is roughly conical in shape, produced by the
extraction of water from a well.
Cone of Depression or Influence
An aquifer whose upper, and perhaps
lower, boundary is defined by a layer of natural material that does not
transmit water readily.
Confined Aquifer
The continuing protection and
management of natural resources in accordance with principles that
assure their optimum long-term economic and social benefits.
conservation
Weir having sufficiently sharp upstream
edges and slow approach velocity to cause the napped to contract.
contracted weir
Loss of water from a channel or pipe
during transport, including losses due to seepage, leakage, evaporation,
and transpiration by plants growing in or near the channel.
conveyance loss
1) Refers to the top of a dam, dike, spillway, or
weir, 2) Summit of a wave or peak of a flood.
crest
Is the depth of flow in a channel at which
specific energy is a minimum for a given discharge.
critical depth
Is a closed conduit usually circular, square or
rectangular in cross section, used for conveying water across and under
an elevated roadway, embankments, or dike.
culvert
Portion of land surface or area from which the earth
or rock has been removed or will be removed by excavation; The depth
below original ground surface to excavated surface.
cut
Process of earth moving by excavating part
of an area and using the excavated material for adjacent embankments
or fill areas.
Cut-and-Fill
Wall, collar, or other surface structure such as
trench filled with relatively impervious material intended to reduce
percolation of water along other smooth surfaces, or through porous
strata.
Cutoff
Surface reservoir designed to trap
sediment and debris.
Debris Basin
A fan-shaped deposit of debris including
soil, sand, gravel, and boulders built up at the point where a mountain
stream meets a valley, or where the velocity of a stream is reduced
sufficiently to cause such deposits.
Debris Cone
Preferential removal of fine soil particles from
the surface soil by wind.
Deflation
Water that moves downward through
the soil profile below the root zone and cannot be used by plants.
Deep Percolation
The difference between the drybulb and wet-bulb temperatures.
Depression, Wet Bulb
Transported material deposited because of
decreased transport capacity of water or wind.
Deposition
A distance measured vertically downward from the
ground surface.
Depth
Dam constructed for the temporary
storage of surface runoff and for releasing the stored water at controlled
rates
Detention Dam
The temperature at which the
condensation of water vapor in a space begins for a given state of
humidity and pressure and as the temperature of the vapor is reduced.
Dew Point Temperature
Any closed conduit (perforated tubing or tile) or
open channel, used for removal of surplus ground or surface water.
Drain
Process of removing surface or subsurface
water from a soil or area.
Drainage
The area from which runoff is collected
and delivered to an outlet
Drainage Basin
Refers to the removal of mud from the bottom
of water bodies using a scooping machine. This disturbs the ecosystem
and causes silting that can kill aquatic life.
Dredging
Serves as an adaptor of the drill bit and
conduit of water jet channel.
Drilling Pipe
Like inclined drops, they are used to carry water
from a higher to a lower elevation but they carry water over longer
distances and flatter slopes and through several changes in grade.
Drops
Overall hydraulic structure in which the
water drops over a vertical wall onto an apron.
Drop Spillway
Are irrigation structures which convey
water from a higher to a lower level, maybe inclined or vertical.
Drop Structures
Is the temperature as
measured by an ordinary dry bulb thermometer.
Dry Bulb Temperature of the Air
An artificial embankment constructed to prevent
flooding.
Dyke [Soil & Water]
Is the vulnerability or susceptibility of the soil
to erosion. It is a function of both the physical properties of the soil and
land management practices.
Erodibility
The wearing away of the land surface by
running water, wind, ice, or other geological agents, including such
processes as gravitational creep.
Erosion
Erosion much more
rapid than normal, natural, or geological erosion, primarily as a result of
the influence of the activities of man or, in some cases, of animals.
Accelerated Erosion
The normal or natural
erosion caused by geological processes acting over long geological
periods.
Geological Erosion
The erosion process whereby
water accumulated in narrow channels and, over short periods, removes
the soil from this narrow area to considerable depths, ranging from 0.5 m
(1.6 ft.) to as much as 30 m (97 ft).
Gully Erosion
The removal of a fairly
uniform layer of soil on a multitude of relatively small areas by splash
due to raindrop impact and by shallow surface flow.
Interrill Erosion [Soil & Water]
It is the wearing away of the
earth’s surface by water, ice, or other natural agents under natural
environmental conditions of climate, vegetation, etc., undisturbed by
man. (See Geological erosion).
Natural Erosion
The gradual erosion of land
used by man which does not greatly exceed natural erosion.
Normal Erosion
An erosion process in which
numerous small channels of only several centimeters in depth are
formed; occurs mainly on recently cultivated soils.
Rill Erosion
The removal of soil from the
land surface by rainfall and surface runoff. Often interpreted to include
rill and interrill erosion.
Sheet Erosion
The detachment and
airborne movement of small soil particles caused by the impact of
raindrops on soils.
Splash Erosion
The potential ability of water, wind, gravity, etc.,
to cause erosion.
Erosivity
The process of changing of the liquid into
vapor form.
Evaporation
The mean rate of evaporation
measured over the past test period; The quantity of water evaporated
from a given water surface per unit of time.
Evaporation Rate
Refer to the
temporary detainment of water in farm pond and dams to mitigate the
erosive capacity of water.
Farm Ponds/Water Impounding Dams [Soil & Water]
Amount of water remaining in soil when
the downward water flow due to gravity becomes negligible.
Field Capacity
Sands, gravels, or fibrous materials placed
around a well screed or perforated casing to increase permeability near
the well and prevent unwanted aquifer particles from entering the well.
Filter (Wells)
Methods or facilities for controlling flood
flows.
Flood Control
The economic loss caused by floods,
including damage by inundation, erosion, and/or sediment deposition.
Flood Damage
Lowland and relatively flat areas adjoining
inland and coastal waters, including floodprone areas of lands. This land
includes, at a minimum, those areas that are subject to a 1 percent or
greater chance of flooding in any given year.
Flood Plains
The highest magnitude of the stage of
discharge attained by a flood. Also called peak stage or peak discharge.
Flood Peak [Soil & Water]
Any normally dry land area that is
susceptible to being inundated by water from any natural source.
Floodplain [Soil & Water]
Volume of water that spreads out
and is temporally stored in a floodplain.
Floodplain Storage [Soil & Water]
Refers to the quantity of fluid in motion pre a unit
of time. It is expressed in mass per unit time or volume per unit time.
Flow Rate
The vertical distance above the elevation of
the hydraulic gradeline at working head to the tops of vents or stand.
Freeboard [Soil & Water]
Friction head loss per unit length of
conduit.
Friction Slope [Soil & Water]
Rectangular or cylindrical wire mesh cage filled
with rock for protecting aprons, stream banks, shorelines, etc., against
erosion.
Gabion [Soil & Water]
Stream or part of a stream that has an
increase in flow because of inflow from ground water.
Gaining Stream [Soil & Water]
A device used to control the flow of water to, from
or in a pipeline; A device used to control the flow of water to, from, or in
a pipeline, or open channel. It may be opened and closed by screw
action, slide action, or hydraulic or pneumatic actuators.
Gate [Soil & Water]
Elevation of a water surface
measured by a gauge.
Gauge Height (Hydraulics) [Soil & Water]
The normal or natural erosion
caused by geological processes acting over long geological periods.
Geological Erosion [Soil & Water]
The process of maintaining constant and
correct slope of a trench, ditch, terrace, canal, etc., using optical or laser
surveying equipment.
Grade Control [Soil & Water]
A line established as aconstruction
reference for ditches, terraces, etc.
Grade Line [Soil & Water]
Is a type of flow if the depth
changes smoothly over a distance.
Gradually Varied Flow [[Soil & Water]
[Soil & Water] An area with vegetative cover
where runoff water infiltrates into the soil.
Grassed Infiltration Area
[Soil & Water] Refers to the establishment of
natural waterways or construction of canals and planting it with grasses
to make it stable and arrest soil erosion.
Grassed Waterways
[Soil & Water] Is not held by the soil but drains
under the influence of gravity.
Gravitational Water
Gravity Inlet [Soil & Water] A structure to control the flow of water from
an open conduit into a pipeline.
Gravity Inlet
[Soil & Water] Water within the earth that supplies wells
and springs.
Groundwater
[Soil & Water] Refers to the flow of water in an
aquifer or soil. That portion of the discharge of a stream that is derived
from ground water
Groundwater Flow
[Soil & Water] Pumping of ground water, for
irrigation or other uses at rates, significantly faster than the rate which
the ground water is being recharged.
Groundwater Mining
[Soil & Water] Refers to the inflow to an
aquifer
Groundwater Recharge
[Soil & Water] Is a groundwater discharge into a
stream due to deep percolation of the infiltrated water into groundwater
aquifers.
Groundwater Runoff
A shallow steep-sided valley that may occur
naturally or be formed by accelerated erosion.
GULLY
[Soil & Water] The energy in the liquid system expressed as the
equivalent height of a water column above a given datum; Quantity used
to express a form of energy content of the liquid per unit weight of the
liquid referred to any arbitrary datum.
Head
[Soil & Water] Ditch across the upper end of a field used for
distributing water in the surface irrigation.
Head Ditch
[Soil & Water] Diversion structures at the upper end of a
conduit or canal.
Head Works
[Soil & Water] Energy loss in fluid flow.
Head Loss
[Soil & Water] Water upstream from a structure; Source of
a stream.
Headwater
A graphical representation of a frequency
distribution by a series of rectangles where the width of the rectangle
represents the range of the variable and the height represents the
frequency of occurrence.
Histogram [Soil & Water]
[Soil & Water] Climate characterized by high rainfall
and low evaporation potential.
Humid Climates
The rate at which water will
move through soil in response to a given potential gradient.
Hydraulic Conductivity [Soil & Water]
[Soil & Water] The hydraulic diameter of an orifice
is 4 times the orifice area divided by the orifice perimeter
Hydraulic Diameter
[Soil & Water] A measure of efficiency with
which a pump imparts energy to water or a turbine extracts energy from
water.
Hydraulic Efficiency
[Soil & Water] Change in the hydraulic head per
unit distance
Hydraulic Gradient
[Soil & Water] Abrupt turbulent rise in water level from
a flow stage less than critical depth to a flow stage greater than critical
depth within which the velocity passes from supercritical to subcritical.
Hydraulic Pump
[Soil & Water] friction along the wetted boundary
of a channel or conduit that causes a loss in head.
Hydraulic Resistance
[Soil & Water] Graphical or tabular representation of the
flow rate of a stream with respect to time.
Hydrograph
[Soil & Water] An indication of the effects of
ground cover and treatment on infiltration and runoff generally estimated
from the density of plants and residue cover on sample areas.
Hydrologic Condition
[Soil & Water] Term used to describe the movement
of water in and on the earth and atmosphere.
Hydrologic Cycle
[Soil & Water] Is a science that treats of the waters of the
Earth, their occurrence, circulation, and distribution, their chemical and
physical properties, and their reaction with their environment, including
their relation to living things.
Hydrology
[Soil & Water] The downward entry of water through the soil
surface into the soil;
Infiltration
[Soil & Water] The rate at which water enters the soil
or other porous material under a given condition, expressed as depth of
water per unit time, usually in millimeters per hour; The quantity of water
that enters the soil surface in a specified time interval.
Infiltration Rate
[Soil & Water] Layer of soil resistant to
penetration by water, air, or roots.
Impermeable Layer, Soil
[Soil & Water] The entry of extraneous rain water into a sewer
system from sources other than infiltration, such as basement drains,
manholes, storm drains, and street washing.
Inflow
[Soil & Water] Stream or portion of stream that
contributes water to the ground water supply.
Influent Stream
[Soil & Water] That portion of precipitation required to
satisfy interception, the wetting of the soil surface, and depression
storage sometimes called “initial abstraction.”
Initial Storage
[Soil & Water] An appurtenance to deliver water to a pipeline
system.
Inlet
[Soil & Water] That portion of precipitation caught by
vegetation and prevented from reaching the soil surface.
Interception
[Soil & Water] A channel located across the flow of
groundwater and installed to collect subsurface flow before it resurfaces.
Surface water is also collected and removed.
Interceptor Drain
[Soil & Water] That which infiltrates into the soil surface and
moves laterally through the upper soil horizons towards streams as
perched groundwater above major groundwater level.
Interflow
[Soil & Water] Secondary dike in a multiple dike flood
protection system.
Interior Dike
[Soil & Water] Drain installed within a dam or other earth
structure as distinguished from peripheral or interceptor drains.
Interior Drain
[Soil & Water] Natural channel in which water
does not flow continuously.
Intermittent Stream
[Soil & Water] The removal of a fairly uniform layer of
soil on a multitude or relatively small areas by splash due to raindrop
impact and by shallow surface flow.
Interrill Erosion
[Soil & Water] The condition of a soil or other porous media
when physical properties, particularly hydraulic conductivity, are equal in
all directions.
Isotropic
[Soil & Water] Terrace that is selected as a reference in
laying out other terraces.
Key Terrace
(Hydrology) [Soil & Water] The interval between the time
when one half of the equivalent uniform excess rain (runoff) has fallen
and the time when the peak of the runoff hydrograph occurs.
Lag Time
Flow in which there are no cross currents or
eddies, and where the fluid elements move in approximately parallel
directions.
laminar flow
[Soil & Water] The operation of shaping the surface of
land to predetermined grades so each row or surface slopes to drain or
is configured for efficient irrigation water applications.
Land Grading
[Soil & Water] Process of shaping the land surface to a
level surface. A special case of lands grading
Land Leveling
[Soil & Water] Refers to the restoration of
productivity to lands made barren through processes such as erosion,
mining or land clearing.
Land Reclamation
[Soil & Water] Water that moves downward through some
porous media and contains dissolved substances removed from media.
Leachate
[Soil & Water] The removal of soluble constituents such as
nitrates or chlorides from soils or other material by water.
Leaching
[Soil & Water] A terrace constructed along the contour
with no slope and with either closed or open channel ends.
Level Terrace
[Soil & Water] A hub-end screw-type or butterfly gate which
is installed in the pipeline.
Line Gate
[Soil & Water] An isolated block of soil, usually undistributed
and in situ, for measuring the quantity, quality, or rate of water
movement through or from the soil.
Lysimeter
[Soil & Water] Cross-sectional area of a stream divided by
its surface width; the average depth.
Mean Depth
[Soil & Water] Is the moisture content in the soil per
unit depth which is usually expressed in inches foot.
Moisture Capacity
[Soil & Water] Depth of flow in an open channel during
uniform flow for the given conditions.
Normal Depth
An opening
with a closed perimeter through which water flows;
orifice
[Soil & Water] Point where water flows from a conduit stream, or
drain.
Outfall
[Soil & Water] An appurtenance to deliver water from a pipe
system to the land or to any surface pipe system.
Outlet
[Soil & Water] That part of surface runoff that flows
over the surface towards the stream channel.
Overhead Flow
[Soil & Water] A weather pattern in which
precipitation is caused by the rising and cooling of air masses as they
are forced upward by topography.
Orographic Storm
[Soil & Water] The area wetted as a percentage
of the total crop area.
Percent Area Wetted
[Soil & Water] A water table, usually of limited
area, maintained above larger ground-water bodies by the presence of
an intervening, relatively impervious confining stratum.
Perched Water Table
[Soil & Water] Subsurface water that flows through
the soil profile of other porous water.
Percolating Water
[Soil & Water] Downward movement of water through the
soil profile or other porous media.
Percolation
[Soil & Water] The rate of movement of water under
hydrostatic pressure down through the interstices of rock, soil, or filtering
media except movement through large openings such as caves: The
rate at which water moves through porous media, such as soil;
Percolation Rate
[Soil & Water] Pipe designed to discharge or accept
water through small, multiple, closely spaced orifices, placed in its
circumference.
Perforated Pipe
[Soil & Water] The property of a material which permits
movement of water through it when saturated and actuated by
hydrostatic pressure of the magnitude normally encountered in natural
subsurface water; The ease with which gases, liquids, or plant roots
penetrate or pass through a layer of soil or porous media.
Permeability
[Soil & Water] Device for containing the soil sample and
subjecting it to fluid flow in order to measure permeability or hydraulic
conductivity.
Permeameter
[Soil & Water] Boundary between segments of a
subsurface body of ground water that contributes to different stream
systems.
Phreatic Divide
Refers to
the soil moisture content when plants permanently wilt. The soil
moisture tension at this point is about 15 atmospheres. Permanent
wilting percentage can be estimated by dividing the field capacity by a
factor ranging from 2.0 to 2.4, with the value higher for soils with higher
silt content.
Permanent Wilting Point (
Highest water velocity in a
channel or conduit that does no cause erosion.
Permissible Velocity
[Soil & Water] Tube for measuring the combined elevation
and pressure head or potential of a fluid; Is a device set in a pipe to
enable a Bourdon gauge or a manometer attached to the piezometer to
show the net or normal pressure.
Piezometer
[Soil & Water] Erosion of flow channels through soil by flowing
water erosion control structure at a transition to drop water into a deeper
drain.
Piping
Property of a wet soil which
allows it to be deformed without appreciable volume change or cracking.
PLASTICITY
[Soil & Water] Is a period of hundreds of thousands of
years of heavy rainfall.
Pluvial Period
[Soil & Water] Water is discharged from
emission points that are individually and relatively widely spaced.
Point-source Emitters
[Soil & Water] The sum of the specific yield and the specific
Retention; The volume of pores and the soil of the sample.
Porosity
[Soil & Water] An outlet used for connecting surface
pipe to an alfalfa valve outlet.
Portable Hydrant
[Soil & Water] Irrigation pipe, which is or can be moved
between irrigation sets, such as sprinkler or gated pipe.
Portable Pipe
Maximum working head of a cast-in-place pipeline shall be 4.5m (15 ft)
above the centerline of the pipe.
PRESSURE
[Soil & Water] A pump which develops most of its
head by the lifting action of vanes on the water.
Propeller Pump
[Soil & Water] A soil which has lost its granular structure
and is in a defloculated condition as a result of tillage, usually when it
was in a wet plastic condition.
Puddled Soil
[Soil & Water] Well drilled into an aquifer which is
pumped to lower the water table.
Pumped Well Drain
Ratio of the water power produced by
the pump, to the power delivered to the pump by the power unit.
pump eff
[Soil & Water] Screen of parallel bars placed in a channel to catch
debris, sometimes called a “bar screen”.
Rack
[Soil & Water] Flow from a source or to a sink along radial
lines. Direction of flow in a centrifugal pump.
Radial Flow
[Soil & Water] Frequency of occurrence of a
rainfall event whose intensity and duration can be expected to be
equaled or exceeded.
Rainfall Frequency
[Soil & Water] Rate of rainfall for any given time
interval, usually expressed in units of depth per time.
Rainfall Intensity
[Soil & Water] The interception and accumulation
of rainfall by the foliage and branches of vegetation.
Rainfall Interception
[Soil & Water] A length of a stream or channel with relativity
constant characteristics.
Reach
body of water that receivers runoff or wastewater discharges
receiving water
descending portion of a stream flow or hydrograph
recession curve
[Soil & Water] Is the time for surface and interflow
to recede; duration of flooding.
Recession Time (tr)
[Soil & Water] Process by which water is added to the zone
of saturation to replenish an aquifer.
Recharge
[Soil & Water] A land area over which water infiltrates
and percolates downward to replenish an aquifer.
Recharge Area
[Soil & Water] Wastewater that is treated and reused
to supplement water supplies.
Reclaimed Water
[Soil & Water] A time period in which a given
hydrologic event can be expected to be equaled or exceeded, usually
expressed in years.
Recurrence Interval
[Soil & Water] Body of water, such as a natural or
constructed lake, in which water is collected and stored for use.
Reservoir
[Soil & Water] A combination of
conversation practices and management identified by land and water
uses that, when installed, will control soil losses and maintain acceptable
water quality to permit sustained use
Resource Management System
[Soil & Water] Precipitation on an area that does not escape
as runoff; the difference between total precipitation and total runoff.
Retention
[Soil & Water] Replacement of existing equipment with
equipment that uses less water.
Retrofit
[Soil & Water] The frequency of occurrence of a
hydrologic event whose intensity and duration can be expected to be
equaled or exceeded, usually expressed in years.
Return Period
[Soil & Water] Small channels eroded into the soil surface by runoff,
which can be filled easily and removed by normal tillage.
Rill
[Soil & Water] An erosion process in which numerous
small channels of only several centimeters in depth are formed; occurs
mainly on recently cultivated soils.
Rill Erosion
[Soil & Water] The soil profile modified by tillage or
amendments for use by plant roots.
Root bed
[Soil & Water] That part of the soil profile exploited by the
roots of plants; Depth of soil that plants roots readily penetrate and in
which the predominant root activity occurs.
Root Zone
[Soil & Water] The portion of precipitation, snow melt, or
irrigation that flows over the soil, eventually making its way to surface
water supplies.
Runoff
[Soil & Water] Soil movement by water or wind where
particles skip or bounce along the streambed or soil surface.
Saltation
[Soil & Water] Flow of water through a porous material
under saturated conditions.
Saturated Flow
[Soil & Water] A soil for which the entire profile is
saturated with water.
Saturated Soil
[Soil & Water] To abrade or wear away; the wearing away of a
channel or surface as in a flood by flowing water.
Scour
[Soil & Water] Any material carried in suspension or bed
load in water which will ultimately settle after the water losses velocity.
Sediment
[Soil & Water] Deposition of waterborne or windborne
particles resulting from a decrease in transport capacity.
Sedimentation
[Soil & Water] Pond at the upper end of a conveyance
or reservoir for detaining particle-laden water for a sufficient length of
time for deposition to occur.
Sediment Basin
[Soil & Water] Amount of sediment carried by running
water or wind.
Sediment Load
[Soil & Water] Percolation of water through the soil; The slow
movement of water through the small cracks, pores, interstices, of a
material;
Seepage
[Soil & Water] An annular plat of concrete or other
impervious material placed on the outside surface of underground
conduits to lengthen the flow path and thus impede seepage.
Seep Collars
Water, usually storm runoff, flowing in a thin
layer over the soil or other smooth surface.
sheet flow
[Soil & Water] Slope of the sides of a channel or
embankment, horizontal to vertical distance
Side Slopes
[Soil & Water] Diverting surface water by means of a
shallow overflow crest to avoid diverting sand, silt, or other debris carried
as bed load.
Skimming
[Soil & Water] A local
government entity within a defined water or soil protection area that
provides assistance to residents in conserving natural resources,
especially soil and water.
Soil and Water Conservation District, SWCD
The proportion of soluble
sodium ions in relation to the soluble calcium and magnesium ions in the
soil water extract.
Sodium Absorption Ratio (SAR)
Is a natural body composed of mineral and organic
material on the surface of the earth in which plants grow.
soil
It is the process by which air and other gases
enter the soil or are exchanged.
soil aeration
The act of reducing the specific volume of
soil.
soil compaction
[Soil & Water] Is the application of engineering
principles to the solution of soil management problems, method used to
fully utilize and conserve soil.
Soil Conservation
[Soil & Water] A measure of the soil’s susceptibility to
erosional processes.
Soil Erodibility
[Soil & Water] Is the detachment and transport of soil
particles from the land by water or wind action.
Soil Erosion
[Soil & Water] Soil-specific
relationship between the soil-water matric potential and soil-water
content.
Soil-water Characteristic Curve
[Soil & Water] Refers to the amount of
water required to raise the soil water content of root zone to field
capacity.
Soil-water Deficit or Depletion
[Soil & Water] It is the amount of work that must
be done per unit quantity of pure water in order to transport reversibly
and isothermally and infinitesimal quantity of water from a pool of pure
water at a specified elevation at atmospheric pressure to the soil water
at the point under consideration.
Soil-water Potential
[Soil & Water] Is a special case of flow in
which the discharge varies with distance along the channel.
Spatially Variable Flow
[Soil & Water] Well discharge divided by the water
level drawdown after a specified pumping duration.
Specific Capacity
The amount of heat which must be removed or
added in order to lower or raise the temperature of one pound of a
substance one degree Fahrenheit.
Specific Heat
[Soil & Water] Amount of water that a unit volume of
porous media or soil, after being saturated, will yield when drained by
gravity
Specific Yield
is a structure for passing out water not needed
for storage or diversion.
spillway
Elevation of a water surface above or below an
established datum; gauge height.
stage
[Soil & Water] Wave on the water surface at an acute
angle to the flow which maintains a relatively constant position.
Standing Wave
[Soil & Water] A vent constructed of vertical pipe on a
pipeline, to relieve pressure surges and water hammer.
Standpipe
[Soil & Water] It is the difference in elevation of the water
surface in a pond, lake, or river from which the water flows from a
submerged discharged pipe. In pumping the groundwater source, static
head is the difference in elevation between the water surface in the well
and the water surface of the discharged canal.
Static Head
A vertical distance between the source and
discharge water in a pump installation.
static lift
[Soil & Water] Is a type of flow if discharge is constant
with respect to time.
Steady Flow
[Soil & Water] Constructed with a stable steep
backslope.
Steep Backslope
[Soil & Water] Is a 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.
Stilling Basin
[Soil & Water] Underground channel with sides and top
lined with flat stones, forming a generally rectangular or triangular
section through which water passes.
Stone Drain
[Soil & Water] Relationship between the volume of
water stored and water surface elevation in a reservoir.
Storage Curve
[Soil & Water] Any body of running water moving under gravity
flow through clearly defined natural channels to progressively lower
levels.
Stream
[Soil & Water] Is an erosion of stream banks by
flowing water.
Stream Bank Erosion
[Soil & Water] It is the discharge that occurs in a natural
channel.
Streamflow
[Soil & Water] Earth material beneath a subsurface drain or
foundation.
Subgrade
[Soil & Water] A collector pipe which serves several laterals
and discharges into a larger main collector pipe
Submain
[Soil & Water] Flow through any critical depth
measuring structure where the downstream water depth is high enough
to interfere with establishment of critical velocity at the control section.
Submerged Flow
Is that part of solum below plow depth or below the
A horizon.
subsoil
[Soil & Water] Measuring weir with sides and bottom
flush with the channel, thus eliminating contractions or nappe of the
overflowing water.
Suppressed Weir
[Soil & Water] Movement of coarse sediment in almost
continuous contract with the soil surface during wind erosion.
Surface Creep
[Soil & Water] The diversion or orderly removal of
excess water from the surface of land by means of improved natural or
constructed channels, supplemented when necessary by shaping or
grading of land surfaces to such channels.
Surface Drainage
[Soil & Water] Structure for diverting surface water into
an open ditch, subsurface drain, or pipeline.
Surface Inlet
[Soil & Water] That portion of precipitation required
to satisfy interpretation, the wetting of the soil surface, and depression
storage.
Surface Retention
[Soil & Water] That which travels over the ground
surface and through the channels to reach the basin outlet.
Surface Runoff
[Soil & Water] Reorienting and packing of dispersed
soil particles in the immediate surface layer of soil and clogging of
surface pores resulting in reduces infiltration.
Surface Sealing
[Soil & Water] Is the upper 12 inches or 30 cm of the soil,
or in arable soils, the depth commonly stirred by the plow.
Surface Soil
[Soil & Water] Sum of detention and channel storage
excluding depression storage, represents at any given moment, the total
water enroute to an outlet from an area or watershed.
Surface Storage
[Soil & Water] Water flowing or stored on the earth’s
surface.
Surface Water
Material moving in suspension in a
fluid, due to the upward components of the turbulent currents or by
colloidal suspension. Sometimes called “suspended load.”
Suspended Sediment
[Soil & Water] Is prepared using the data from
a number of watershed to develop dimensionless unit hydrographs
which are applicable to ungaged watersheds. Also a dimensionless
hydrograph that 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.
Synthetic Hydrograph
[Soil & Water] The temperature of an air
mass at which the condensation of water vapor begins as the
temperature of the air mass is reduced.
Temperature, Dewpoint
[Soil & Water] The temperature of a gas or
mixture of gases indicated by an accurate thermometer protected from
or corrected for radiation effects.
Temperature, Dry-bulb
[Soil & Water] Wet-bulb temperature is the
temperature indicated by a wet-bulb sensor of a psychrometer
constructed and used according to instructions.
Temperature, Wet-bulb
[Soil & Water] A type of soil moisture probe used to
monitor soil moisture conditions to help determine when water should be
applied.
Tensiometer
[Soil & Water] A broad surface running along the contour. It
can be a natural phenomenon or specially constructed to intercept
runoff, thereby preventing erosion and conserving moisture. Sometimes
they are built to provide adequate rooting depths for plants.
Terrace
[Soil & Water] Level terraces built in
stair-step fashion with a level to p and a steep, vertical embankment
between successive terraces, used to improve distribution of rainfall or
irrigation water.
Terrace System-Bench Terrace
[Soil & Water] A type of terrace
constructed so that crops a can be planted and machinery safely
operated on the netire cross section.
Broadbase Terrace
[Soil & Water] Terrace
which is constructed by moving soil for the embankment from the uphill
side only.
Channel-type Terrace
[Soil & Water] A
broad level or flat channel terrace constructed below a sloping runoff,
with erosion control as the primary objective.
Conservation Bench Terrace
[Soil & Water] A terrace whose back
and front slopes are constructed with steep but stable slopes and kept in
permanent vegetation.
Grade Terrace
[Soil & Water] A terrace constructed
along the contour with no slope and with either closed or open channel
ends. Used primarily to retain runoff.
Level Terrace
[Soil & Water] Is the 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.
Terracing
[Soil & Water] Is the location of the rain gauges that
are plotted on the map of the area and stations and are connected by
straight lines.
Theissen Polygon
[Soil & Water] Support laid underneath a tile line in
unstable soil to keep horizontal and vertical alignment of the tile line.
Tile Cradle
[Soil & Water] Quality of a tile that determines its crushing
strength, and its ability to resist water absorption and damage by
freezing and thawing.
Tile Density
[Soil & Water] Short lengths of concrete or pottery pipes
placed end to end at a suitable depth and spacing in the soil to collect
water from the soil and lead it to an outlet.
Tile Drain
[Soil & Water] Opening between 2 drain tiles through which
water from the surrounding soil flows.
Tile Joint
[Soil & Water] It is the time required for
precipitation excess to flow from the most remote point of a watershed to
the outlet.
Time of Concentration
[Soil & Water] It is used for flood forecasting and
water quality studies; watershed response time.
Time to Peak (tp)
[Soil & Water] Horizontal distance across the top of a ditch
or embankment.
Top Width
[Soil & Water] Is the reading of a pressure gage
at the discharge of the pump, converted into feet of liquid and referred to
datum, plus velocity head at the point of gage attachment.
Total Discharge Head
[Soil & Water] It is the head required to lift water
from the water source to the centerline of the pump plus velocity head,
entrance losses and friction losses in suction pipeline.
Total Suction Head
[Soil & Water] A sharp sided 90 deg. V-notch weir.
Triangular Weir
[Soil & Water] A stream that contributes its water to another
stream or body of water.
Tributary
[Soil & Water] A pipe or other conduit through an
embankment to carry low flows to maintain a constant water level in a
reservoir.
Trickle Spillway
[Soil & Water] A flow in which the fluid particles move
in an irregular random manner, in which the head loss is approximately
proportional to the second power of the velocity.
Turbulent Flow
[Soil & Water] An aquifer whose upper boundary
consists of relatively porous natural material that transmits water readily
and does not confine water.
Unconfined Aquifer
[Soil & Water] Erosion of material at the base of a steep
slope, overfall, or cliff by falling water, stream, wind, or wave action;
produces an overhanging cliff.
Undercutting
[Soil & Water] Flow in which the velocity and depth are
the same at each cross section.
Uniform Flow
[Soil & Water] Is a hydrograph with a unit volume of
direct runoff for a given storm duration. It represents the response of the
basin on a given storm duration and characteristics, and enables one to
synthesize hydrographs for complex storms by superimposing the
hydrographs resulting from the individual components of the storm.
Unit Hydrograph
[Soil & Water] Movement of water in soil in which
the pores are not completely filled with water.
Unsaturated Flow
[Soil & Water] That part of the soil profile in which
the voids are not completely filled with water.
Unsaturated Zone
[Soil & Water] A type of flow in which discharge is not
constant with respect to time.
Unsteady Flow
[Soil & Water] An area where soils are generally relatively well
drained such that the water table is significantly below the soil surface
most of the year.
Upland
[Soil & Water] Zone of unsaturated soil that extends from
the soil surface to the ground-water table.
Vadose Zone
[Soil & Water] Flow measuring flume with a contracted
throat that causes a drop in the hydraulic grade line ( preferred term is
Parshall flume).
Venturi Flume
Is when the water molecules in the air exert
a particular pressure.
vapor pressure
Is when the water molecules in the air exert
a particular pressure.
vapor pressure
[Soil & Water] Difference between the existing
vapor pressure and that of a saturated atmospheric vapor pressure at
the same temperature.
Vapor Pressure Deficit
[Soil & Water] That part of the sediment load of a stream
that is composed of suspended clay and silt particles.
Wash Load
Water is reduced quality that has been used for
some purpose and discarded.
wastewater
[Soil & Water] It is the ratio between the
water stored in the soil root zone during irrigation and the water
delivered to the farm expressed in percent.
Water Application Efficiency
[Soil & Water] Protection and management of
water resources for maximum sustained benefits.
Water Conservation
[Soil & Water] Ratio of the volume of
irrigation water delivered by a distribution system to the water introduced
into the system.
Water Conveyance Efficiency
[Soil & Water] Amount of soil water available
in plants.
Water Holding Capacity
[Soil & Water] A method of land grading wherein fields
are divided into segments, flooded, and the highs are scraped down unit
all soil is beneath the water surface.
Water Leveling
[Soil & Water] Pipe that conveys water from supply to
storage or use.
Waterline
[Soil & Water] A term used to describe the chemical,
physical, and biological characteristics of water with respect to its
suitability for a particular use.
Water Quality
[Soil & Water] Legal rights to use water supplies derived
from common law, court decisions, or statutory enactment.
Water Rights
[Soil & Water] Using wastewater or reclaimed water from
one application for another application.
Water Reuse
[Soil & Water] Is a topographically delineated area which
drains into a reference point in the stream.
Watershed
[Soil & Water] It is the ratio of water stored
in the root zone during the irrigation to the water needed in the root zone
prior to irrigation, expressed in percent.
Water Storage Efficiency
[Soil & Water] The collection, treatment,
storage, and distribution of potable water from source to consumer.
Water Supply System
[Soil & Water] Imposition of a higher rate on
excessive water use.
Water Surcharge
[Soil & Water] Structure across a stream to control or divert the
flow; Device for measuring the flow of water.
Weir
[Soil & Water] A pit, hole, or shaft sunk into the earth to tap an
underground source of water.
Well
[Soil & Water] A pipe installed within a borehole to prevent
collapse of sidewall material, to receive and protect pump and pump
column, and to allow water flow from the aquifer to pump intake.
Well Casing
[Soil & Water] It is the process of removing fine
formation materials or materials introduced during well construction from
the well intake zone for the purpose of stabilizing and increasing the
permeability of the well intake zone and the filter pack material.
Well Development
[Soil & Water] Determination of well yield vs. drawdown
relationship with time.
Well Test
[Soil & Water] Discharge rate can be sustained from a well
for some specified period of time.
Well Yield
[Soil & Water] The difference between the dryand wet-bulb temperatures.
Wet Bulb Depression
[Soil & Water] Numerical quantity to designate the
relation of precipitation or annual runoff for a given year to the long term
average.
Wetness Index
[Soil & Water] The average irrigated soil area in a
horizontal plane located at or below the emitter.
Wetted Area
[Soil & Water] Diameter of the wetted circle created
by a single sprinkler head.
Wetted Diameter
[Soil & Water] Length of the wetted contact between
a conveyed liquid and the open channel or closed conduit conveying it,
measured ina plane at right angles to the direction of flow.
Wheatstone Bridge [Ag Elec] Circuit configuration used to
Wetted Perimeter
[Soil & Water] Is held with a force of 15 atm.
Wilting point of wilting coefficient also indicates the percentage moisture
content of a soil at which a plant wilts and will not be able to recover.
Wilting Percentage
[Soil & Water] Detachment, transportation, and
deposition of soil by the action of wind.
Wind Erosion
[Soil & Water] A means of measuring wind velocity with
an accuracy of ± 3km/h (± 2mph)
Wind Velocity
[Soil & Water] Detachment, transportation, and
deposition of soil by the action of wind.
Wind Erosion
[Soil & Water] Earth embankment having sections
such as cores and diaphragms of varying permeability to control
seepage.
Zone Embankment
[Soil & Water] A subsurface zone in which all the
pores or the material are filled with groundwater under pressure greater
than atmospheric pressure.
Zone of Saturation
