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]
