PART 2: HYDROLOGY AND SWE GLOSSARY OF TERMS Flashcards
(367 cards)
1
Q
A kind of well that has been treated to
eliminate the potential for contamination of aquifer.
A
abandoned well
2
Q
Dike and drainage structure protecting
marshlands; Outlet structure with flap gate which permits outflow of
fresh water, but prevents inflow of tidal salt water.
A
Aboiteaux
3
Q
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.
A
Accelerated Erosion
4
Q
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.
A
Accumulation
5
Q
Is a soil with a pH below 7.0.
A
acid soil
6
Q
Refers to the volume of water that would
cover one acre to a depth of one foot
A
acre-foot
7
Q
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.
A
Aerated Static Pile
8
Q
The decay organic matter by
microorganisms in the presence of oxygen.
A
aerobic decomposition
9
Q
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
A-frame
10
Q
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.
A
air capacity of soils
11
Q
Upward movement of air through the
soil during downward flow (percolation) water.
A
Air Counter Flow
12
Q
Renewal of soil by air diffusion.
A
air drainage
13
Q
Device that releases air from a pipeline
automatically without permitting loss of water.
A
air relief valve
14
Q
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.
A
Alfalfa Valve
15
Q
Soils not having the same physical
properties when the direction of measurement is changed.
A
Anisotropic Soils
16
Q
Flow
rate of water passing through a unit cross section of porous media.
A
Apparent Flow Velocity
17
Q
Rate that water is applied to a given
area. Usually expressed in units of depth per time;
A
Application Rate
18
Q
Floor lining extending downstream from a
hydraulic structure to protect the structure from erosion and scour;
A
Apron
19
Q
Underground geologic formation that neither
yields nor allows the passage of an appreciable quantity of water,
although it may be saturated with water itself
A
aquiclude
20
Q
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.
A
Aquifer
21
Q
Underground geologic formation that is slightly
permeable and yields inappreciable amounts of water when compared to
an aquifer.
A
aquitard
22
Q
Curved masonry concrete dam, convex
upstream, that depends to arch action for its stability.
A
arched dam
23
Q
Climate characterized by low rainfall and
high evaporation potential.
A
arid climate
24
Q
Aquifer that contains water under
pressure as a result of hydrostatic head.
A
artesian aquifer
25
is
the ratio of the length of the longer sides to the length of the shorter
sides.
aspect ratio
26
Natural ability of soil, air or water
to accept and/or degrade potential pollutants without harmful effects to
the environment.
Assimilative Capacity
27
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
28
Dam spillway built to carry runoff in
excess of that carried by the principal spillway. This is sometimes called
emergency spillway.
Auxiliary Spillway
29
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
30
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
31
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
32
The horizontal angle in degrees measured from
due south in the northern hemisphere (due north in the southern
hemisphere)
azimuth
33
The replacement of the
excavated material after drain replacement and blinding, or envelope
installation.
Backfilling (Drainage)
34
Land area on the downhill side of a terrace
ridge or earth embankment.
Backslope
35
Water leaving a stream channel during
rising stages of stream flow, most of which returns to stream flow during
falling stages
bank storage
36
(1) The cross-sectional area of the base of a
cone penetrometer, (2) Contact area of a dam with original surface.
base area
37
Circle of an involute cylindrical gear, the
“base circle” of the involutes forming the tooth profile.
base circle
38
Water in a stream that results from groundwater inflow i.e., that which is not affected by surface inflow.
baseflow
39
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
40
Irrigation by flooding areas of level land
surrounded by dikes.
basin irrigation
41
A surface drainage method accomplished by
plowing land to form a series of low narrow ridges separated by parallel
dead furrows.
bedding
42
The acute angle of a V-groove in the
bottom of a trench for support of pipe drains.
bedding angle
43
Coarse sediment or material moving on or
near the bottom of a flowing channel by rolling, sliding or bouncing.
bed load
44
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
45
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
46
Strip or area of land, usually level, between the
edge of spoil bank and edge of a ditch or canal.
berm
47
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)
48
Breaking down of natural or synthetic
organic materials by microorganisms in soils, natural bodies of water,
wastewater treatment systems.
biodegradation
49
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
50
A type of terrace constructed so
that crops can be planted and machinery safely operated on the entire
cross section.
Broadbase Terrace
51
Weir for water measurement having
a rounded or wide crest in the direction of the stream.
Broad-Crested Weir
52
The mass of dry soil per unit bulk
volume.
bulk density
53
Vegetative cover over the land surface of a
catchment area.
canopy
54
Entrance to a closed conduit that has been
covered or shielded to induce priming aluminum submergence.
canopy inlet
55
A zone in the soil just above the water
table that remains saturated or almost
unsaturated.
capillary fringe
56
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
57
(Preferred term is Soil-water
pressure).
capillary pressure
58
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
59
Is held by the surface tension forces as
a continuous film around the particles and in the capillary spaces.
CAPILLARY WATER
60
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
61
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
62
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
63
A structure to control water depth in a canal, ditch
or irrigated field.
Check
64
Small barrier constructed in a gully or other
small watercourse to decrease flow velocity, minimize channel scour,
and promote deposition of sediment.
check Dam
65
Lined channel constructed with a steep
slope to convey water to lower level without erosion.
chute spillway
66
Man-made reservoir or receptable for holding
water or other liquids
cistern
67
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
68
An aquifer whose upper, and perhaps
lower, boundary is defined by a layer of natural material that does not
transmit water readily.
Confined Aquifer
69
The continuing protection and
management of natural resources in accordance with principles that
assure their optimum long-term economic and social benefits.
conservation
70
Weir having sufficiently sharp upstream
edges and slow approach velocity to cause the napped to contract.
contracted weir
71
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
72
1) Refers to the top of a dam, dike, spillway, or
weir, 2) Summit of a wave or peak of a flood.
crest
73
Is the depth of flow in a channel at which
specific energy is a minimum for a given discharge.
critical depth
74
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
75
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
76
Process of earth moving by excavating part
of an area and using the excavated material for adjacent embankments
or fill areas.
Cut-and-Fill
77
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
78
Surface reservoir designed to trap
sediment and debris.
Debris Basin
79
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
80
Preferential removal of fine soil particles from
the surface soil by wind.
Deflation
81
Water that moves downward through
the soil profile below the root zone and cannot be used by plants.
Deep Percolation
82
The difference between the drybulb and wet-bulb temperatures.
Depression, Wet Bulb
83
Transported material deposited because of
decreased transport capacity of water or wind.
Deposition
84
A distance measured vertically downward from the
ground surface.
Depth
85
Dam constructed for the temporary
storage of surface runoff and for releasing the stored water at controlled
rates
Detention Dam
86
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
87
Any closed conduit (perforated tubing or tile) or
open channel, used for removal of surplus ground or surface water.
Drain
88
Process of removing surface or subsurface
water from a soil or area.
Drainage
89
The area from which runoff is collected
and delivered to an outlet
Drainage Basin
90
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
91
Serves as an adaptor of the drill bit and
conduit of water jet channel.
Drilling Pipe
92
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
93
Overall hydraulic structure in which the
water drops over a vertical wall onto an apron.
Drop Spillway
94
Are irrigation structures which convey
water from a higher to a lower level, maybe inclined or vertical.
Drop Structures
95
Is the temperature as
measured by an ordinary dry bulb thermometer.
Dry Bulb Temperature of the Air
96
An artificial embankment constructed to prevent
flooding.
Dyke [Soil & Water]
97
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
98
The wearing away of the land surface by
running water, wind, ice, or other geological agents, including such
processes as gravitational creep.
Erosion
99
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
100
The normal or natural
erosion caused by geological processes acting over long geological
periods.
Geological Erosion
101
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
102
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]
103
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
104
The gradual erosion of land
used by man which does not greatly exceed natural erosion.
Normal Erosion
105
An erosion process in which
numerous small channels of only several centimeters in depth are
formed; occurs mainly on recently cultivated soils.
Rill Erosion
106
The removal of soil from the
land surface by rainfall and surface runoff. Often interpreted to include
rill and interrill erosion.
Sheet Erosion
107
The detachment and
airborne movement of small soil particles caused by the impact of
raindrops on soils.
Splash Erosion
108
The potential ability of water, wind, gravity, etc.,
to cause erosion.
Erosivity
109
The process of changing of the liquid into
vapor form.
Evaporation
110
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
111
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]
112
Amount of water remaining in soil when
the downward water flow due to gravity becomes negligible.
Field Capacity
113
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)
114
Methods or facilities for controlling flood
flows.
Flood Control
115
The economic loss caused by floods,
including damage by inundation, erosion, and/or sediment deposition.
Flood Damage
116
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
117
The highest magnitude of the stage of
discharge attained by a flood. Also called peak stage or peak discharge.
Flood Peak [Soil & Water]
118
Any normally dry land area that is
susceptible to being inundated by water from any natural source.
Floodplain [Soil & Water]
119
Volume of water that spreads out
and is temporally stored in a floodplain.
Floodplain Storage [Soil & Water]
120
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
121
The vertical distance above the elevation of
the hydraulic gradeline at working head to the tops of vents or stand.
Freeboard [Soil & Water]
122
Friction head loss per unit length of
conduit.
Friction Slope [Soil & Water]
123
Rectangular or cylindrical wire mesh cage filled
with rock for protecting aprons, stream banks, shorelines, etc., against
erosion.
Gabion [Soil & Water]
124
Stream or part of a stream that has an
increase in flow because of inflow from ground water.
Gaining Stream [Soil & Water]
125
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]
126
Elevation of a water surface
measured by a gauge.
Gauge Height (Hydraulics) [Soil & Water]
127
The normal or natural erosion
caused by geological processes acting over long geological periods.
Geological Erosion [Soil & Water]
128
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]
129
A line established as aconstruction
reference for ditches, terraces, etc.
Grade Line [Soil & Water]
130
Is a type of flow if the depth
changes smoothly over a distance.
Gradually Varied Flow [[Soil & Water]
131
[Soil & Water] An area with vegetative cover
where runoff water infiltrates into the soil.
Grassed Infiltration Area
132
[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
133
[Soil & Water] Is not held by the soil but drains
under the influence of gravity.
Gravitational Water
134
Gravity Inlet [Soil & Water] A structure to control the flow of water from
an open conduit into a pipeline.
Gravity Inlet
135
[Soil & Water] Water within the earth that supplies wells
and springs.
Groundwater
136
[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
137
[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
138
[Soil & Water] Refers to the inflow to an
aquifer
Groundwater Recharge
139
[Soil & Water] Is a groundwater discharge into a
stream due to deep percolation of the infiltrated water into groundwater
aquifers.
Groundwater Runoff
140
A shallow steep-sided valley that may occur
naturally or be formed by accelerated erosion.
GULLY
141
[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
142
[Soil & Water] Ditch across the upper end of a field used for
distributing water in the surface irrigation.
Head Ditch
143
[Soil & Water] Diversion structures at the upper end of a
conduit or canal.
Head Works
144
[Soil & Water] Energy loss in fluid flow.
Head Loss
145
[Soil & Water] Water upstream from a structure; Source of
a stream.
Headwater
146
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]
147
[Soil & Water] Climate characterized by high rainfall
and low evaporation potential.
Humid Climates
148
The rate at which water will
move through soil in response to a given potential gradient.
Hydraulic Conductivity [Soil & Water]
149
[Soil & Water] The hydraulic diameter of an orifice
is 4 times the orifice area divided by the orifice perimeter
Hydraulic Diameter
150
[Soil & Water] A measure of efficiency with
which a pump imparts energy to water or a turbine extracts energy from
water.
Hydraulic Efficiency
151
[Soil & Water] Change in the hydraulic head per
unit distance
Hydraulic Gradient
152
[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
153
[Soil & Water] friction along the wetted boundary
of a channel or conduit that causes a loss in head.
Hydraulic Resistance
154
[Soil & Water] Graphical or tabular representation of the
flow rate of a stream with respect to time.
Hydrograph
155
[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
156
[Soil & Water] Term used to describe the movement
of water in and on the earth and atmosphere.
Hydrologic Cycle
157
[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
158
[Soil & Water] The downward entry of water through the soil
surface into the soil;
Infiltration
159
[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
160
[Soil & Water] Layer of soil resistant to
penetration by water, air, or roots.
Impermeable Layer, Soil
161
[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
162
[Soil & Water] Stream or portion of stream that
contributes water to the ground water supply.
Influent Stream
163
[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
164
[Soil & Water] An appurtenance to deliver water to a pipeline
system.
Inlet
165
[Soil & Water] That portion of precipitation caught by
vegetation and prevented from reaching the soil surface.
Interception
166
[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
167
[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
168
[Soil & Water] Secondary dike in a multiple dike flood
protection system.
Interior Dike
169
[Soil & Water] Drain installed within a dam or other earth
structure as distinguished from peripheral or interceptor drains.
Interior Drain
170
[Soil & Water] Natural channel in which water
does not flow continuously.
Intermittent Stream
171
[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
172
[Soil & Water] The condition of a soil or other porous media
when physical properties, particularly hydraulic conductivity, are equal in
all directions.
Isotropic
173
[Soil & Water] Terrace that is selected as a reference in
laying out other terraces.
Key Terrace
174
(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
175
Flow in which there are no cross currents or
eddies, and where the fluid elements move in approximately parallel
directions.
laminar flow
176
[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
177
[Soil & Water] Process of shaping the land surface to a
level surface. A special case of lands grading
Land Leveling
178
[Soil & Water] Refers to the restoration of
productivity to lands made barren through processes such as erosion,
mining or land clearing.
Land Reclamation
179
[Soil & Water] Water that moves downward through some
porous media and contains dissolved substances removed from media.
Leachate
180
[Soil & Water] The removal of soluble constituents such as
nitrates or chlorides from soils or other material by water.
Leaching
181
[Soil & Water] A terrace constructed along the contour
with no slope and with either closed or open channel ends.
Level Terrace
182
[Soil & Water] A hub-end screw-type or butterfly gate which
is installed in the pipeline.
Line Gate
183
[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
184
[Soil & Water] Cross-sectional area of a stream divided by
its surface width; the average depth.
Mean Depth
185
[Soil & Water] Is the moisture content in the soil per
unit depth which is usually expressed in inches foot.
Moisture Capacity
186
[Soil & Water] Depth of flow in an open channel during
uniform flow for the given conditions.
Normal Depth
187
An opening
with a closed perimeter through which water flows;
orifice
188
[Soil & Water] Point where water flows from a conduit stream, or
drain.
Outfall
189
[Soil & Water] An appurtenance to deliver water from a pipe
system to the land or to any surface pipe system.
Outlet
190
[Soil & Water] That part of surface runoff that flows
over the surface towards the stream channel.
Overhead Flow
191
[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
192
[Soil & Water] The area wetted as a percentage
of the total crop area.
Percent Area Wetted
193
[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
194
[Soil & Water] Subsurface water that flows through
the soil profile of other porous water.
Percolating Water
195
[Soil & Water] Downward movement of water through the
soil profile or other porous media.
Percolation
196
[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
197
[Soil & Water] Pipe designed to discharge or accept
water through small, multiple, closely spaced orifices, placed in its
circumference.
Perforated Pipe
198
[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
199
[Soil & Water] Device for containing the soil sample and
subjecting it to fluid flow in order to measure permeability or hydraulic
conductivity.
Permeameter
200
[Soil & Water] Boundary between segments of a
subsurface body of ground water that contributes to different stream
systems.
Phreatic Divide
201
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 (
202
Highest water velocity in a
channel or conduit that does no cause erosion.
Permissible Velocity
203
[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
204
[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
205
Property of a wet soil which
allows it to be deformed without appreciable volume change or cracking.
PLASTICITY
206
[Soil & Water] Is a period of hundreds of thousands of
years of heavy rainfall.
Pluvial Period
207
[Soil & Water] Water is discharged from
emission points that are individually and relatively widely spaced.
Point-source Emitters
208
[Soil & Water] The sum of the specific yield and the specific
Retention; The volume of pores and the soil of the sample.
Porosity
209
[Soil & Water] An outlet used for connecting surface
pipe to an alfalfa valve outlet.
Portable Hydrant
210
[Soil & Water] Irrigation pipe, which is or can be moved
between irrigation sets, such as sprinkler or gated pipe.
Portable Pipe
211
Maximum working head of a cast-in-place pipeline shall be 4.5m (15 ft)
above the centerline of the pipe.
PRESSURE
212
[Soil & Water] A pump which develops most of its
head by the lifting action of vanes on the water.
Propeller Pump
213
[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
214
[Soil & Water] Well drilled into an aquifer which is
pumped to lower the water table.
Pumped Well Drain
215
Ratio of the water power produced by
the pump, to the power delivered to the pump by the power unit.
pump eff
216
[Soil & Water] Screen of parallel bars placed in a channel to catch
debris, sometimes called a "bar screen".
Rack
217
[Soil & Water] Flow from a source or to a sink along radial
lines. Direction of flow in a centrifugal pump.
Radial Flow
218
[Soil & Water] Frequency of occurrence of a
rainfall event whose intensity and duration can be expected to be
equaled or exceeded.
Rainfall Frequency
219
[Soil & Water] Rate of rainfall for any given time
interval, usually expressed in units of depth per time.
Rainfall Intensity
220
[Soil & Water] The interception and accumulation
of rainfall by the foliage and branches of vegetation.
Rainfall Interception
221
[Soil & Water] A length of a stream or channel with relativity
constant characteristics.
Reach
222
body of water that receivers runoff or wastewater discharges
receiving water
223
descending portion of a stream flow or hydrograph
recession curve
224
[Soil & Water] Is the time for surface and interflow
to recede; duration of flooding.
Recession Time (tr)
225
[Soil & Water] Process by which water is added to the zone
of saturation to replenish an aquifer.
Recharge
226
[Soil & Water] A land area over which water infiltrates
and percolates downward to replenish an aquifer.
Recharge Area
227
[Soil & Water] Wastewater that is treated and reused
to supplement water supplies.
Reclaimed Water
228
[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
229
[Soil & Water] Body of water, such as a natural or
constructed lake, in which water is collected and stored for use.
Reservoir
230
[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
231
[Soil & Water] Precipitation on an area that does not escape
as runoff; the difference between total precipitation and total runoff.
Retention
232
[Soil & Water] Replacement of existing equipment with
equipment that uses less water.
Retrofit
233
[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
234
[Soil & Water] Small channels eroded into the soil surface by runoff,
which can be filled easily and removed by normal tillage.
Rill
235
[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
236
[Soil & Water] The soil profile modified by tillage or
amendments for use by plant roots.
Root bed
237
[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
238
[Soil & Water] The portion of precipitation, snow melt, or
irrigation that flows over the soil, eventually making its way to surface
water supplies.
Runoff
239
[Soil & Water] Soil movement by water or wind where
particles skip or bounce along the streambed or soil surface.
Saltation
240
[Soil & Water] Flow of water through a porous material
under saturated conditions.
Saturated Flow
241
[Soil & Water] A soil for which the entire profile is
saturated with water.
Saturated Soil
242
[Soil & Water] To abrade or wear away; the wearing away of a
channel or surface as in a flood by flowing water.
Scour
243
[Soil & Water] Any material carried in suspension or bed
load in water which will ultimately settle after the water losses velocity.
Sediment
244
[Soil & Water] Deposition of waterborne or windborne
particles resulting from a decrease in transport capacity.
Sedimentation
245
[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
246
[Soil & Water] Amount of sediment carried by running
water or wind.
Sediment Load
247
[Soil & Water] Percolation of water through the soil; The slow
movement of water through the small cracks, pores, interstices, of a
material;
Seepage
248
[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
249
Water, usually storm runoff, flowing in a thin
layer over the soil or other smooth surface.
sheet flow
250
[Soil & Water] Slope of the sides of a channel or
embankment, horizontal to vertical distance
Side Slopes
251
[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
252
[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
253
The proportion of soluble
sodium ions in relation to the soluble calcium and magnesium ions in the
soil water extract.
Sodium Absorption Ratio (SAR)
254
Is a natural body composed of mineral and organic
material on the surface of the earth in which plants grow.
soil
255
It is the process by which air and other gases
enter the soil or are exchanged.
soil aeration
256
The act of reducing the specific volume of
soil.
soil compaction
257
[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
258
[Soil & Water] A measure of the soil’s susceptibility to
erosional processes.
Soil Erodibility
259
[Soil & Water] Is the detachment and transport of soil
particles from the land by water or wind action.
Soil Erosion
260
[Soil & Water] Soil-specific
relationship between the soil-water matric potential and soil-water
content.
Soil-water Characteristic Curve
261
[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
262
[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
263
[Soil & Water] Is a special case of flow in
which the discharge varies with distance along the channel.
Spatially Variable Flow
264
[Soil & Water] Well discharge divided by the water
level drawdown after a specified pumping duration.
Specific Capacity
265
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
266
[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
267
is a structure for passing out water not needed
for storage or diversion.
spillway
268
Elevation of a water surface above or below an
established datum; gauge height.
stage
269
[Soil & Water] Wave on the water surface at an acute
angle to the flow which maintains a relatively constant position.
Standing Wave
270
[Soil & Water] A vent constructed of vertical pipe on a
pipeline, to relieve pressure surges and water hammer.
Standpipe
271
[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
272
A vertical distance between the source and
discharge water in a pump installation.
static lift
273
[Soil & Water] Is a type of flow if discharge is constant
with respect to time.
Steady Flow
274
[Soil & Water] Constructed with a stable steep
backslope.
Steep Backslope
275
[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
276
[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
277
[Soil & Water] Relationship between the volume of
water stored and water surface elevation in a reservoir.
Storage Curve
278
[Soil & Water] Any body of running water moving under gravity
flow through clearly defined natural channels to progressively lower
levels.
Stream
279
[Soil & Water] Is an erosion of stream banks by
flowing water.
Stream Bank Erosion
280
[Soil & Water] It is the discharge that occurs in a natural
channel.
Streamflow
281
[Soil & Water] Earth material beneath a subsurface drain or
foundation.
Subgrade
282
[Soil & Water] A collector pipe which serves several laterals
and discharges into a larger main collector pipe
Submain
283
[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
284
Is that part of solum below plow depth or below the
A horizon.
subsoil
285
[Soil & Water] Measuring weir with sides and bottom
flush with the channel, thus eliminating contractions or nappe of the
overflowing water.
Suppressed Weir
286
[Soil & Water] Movement of coarse sediment in almost
continuous contract with the soil surface during wind erosion.
Surface Creep
287
[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
288
[Soil & Water] Structure for diverting surface water into
an open ditch, subsurface drain, or pipeline.
Surface Inlet
289
[Soil & Water] That portion of precipitation required
to satisfy interpretation, the wetting of the soil surface, and depression
storage.
Surface Retention
290
[Soil & Water] That which travels over the ground
surface and through the channels to reach the basin outlet.
Surface Runoff
291
[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
292
[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
293
[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
294
[Soil & Water] Water flowing or stored on the earth’s
surface.
Surface Water
295
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
296
[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
297
[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
298
[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
299
[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
300
[Soil & Water] A type of soil moisture probe used to
monitor soil moisture conditions to help determine when water should be
applied.
Tensiometer
301
[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
302
[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
303
[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
304
[Soil & Water] Terrace
which is constructed by moving soil for the embankment from the uphill
side only.
Channel-type Terrace
305
[Soil & Water] A
broad level or flat channel terrace constructed below a sloping runoff,
with erosion control as the primary objective.
Conservation Bench Terrace
306
[Soil & Water] A terrace whose back
and front slopes are constructed with steep but stable slopes and kept in
permanent vegetation.
Grade Terrace
307
[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
308
[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
309
[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
310
[Soil & Water] Support laid underneath a tile line in
unstable soil to keep horizontal and vertical alignment of the tile line.
Tile Cradle
311
[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
312
[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
313
[Soil & Water] Opening between 2 drain tiles through which
water from the surrounding soil flows.
Tile Joint
314
[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
315
[Soil & Water] It is used for flood forecasting and
water quality studies; watershed response time.
Time to Peak (tp)
316
[Soil & Water] Horizontal distance across the top of a ditch
or embankment.
Top Width
317
[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
318
[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
319
[Soil & Water] A sharp sided 90 deg. V-notch weir.
Triangular Weir
320
[Soil & Water] A stream that contributes its water to another
stream or body of water.
Tributary
321
[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
322
[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
323
[Soil & Water] An aquifer whose upper boundary
consists of relatively porous natural material that transmits water readily
and does not confine water.
Unconfined Aquifer
324
[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
325
[Soil & Water] Flow in which the velocity and depth are
the same at each cross section.
Uniform Flow
326
[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
327
[Soil & Water] Movement of water in soil in which
the pores are not completely filled with water.
Unsaturated Flow
328
[Soil & Water] That part of the soil profile in which
the voids are not completely filled with water.
Unsaturated Zone
329
[Soil & Water] A type of flow in which discharge is not
constant with respect to time.
Unsteady Flow
330
[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
331
[Soil & Water] Zone of unsaturated soil that extends from
the soil surface to the ground-water table.
Vadose Zone
332
[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
333
Is when the water molecules in the air exert
a particular pressure.
vapor pressure
334
Is when the water molecules in the air exert
a particular pressure.
vapor pressure
335
[Soil & Water] Difference between the existing
vapor pressure and that of a saturated atmospheric vapor pressure at
the same temperature.
Vapor Pressure Deficit
336
[Soil & Water] That part of the sediment load of a stream
that is composed of suspended clay and silt particles.
Wash Load
337
Water is reduced quality that has been used for
some purpose and discarded.
wastewater
338
[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
339
[Soil & Water] Protection and management of
water resources for maximum sustained benefits.
Water Conservation
340
[Soil & Water] Ratio of the volume of
irrigation water delivered by a distribution system to the water introduced
into the system.
Water Conveyance Efficiency
341
[Soil & Water] Amount of soil water available
in plants.
Water Holding Capacity
342
[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
343
[Soil & Water] Pipe that conveys water from supply to
storage or use.
Waterline
344
[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
345
[Soil & Water] Legal rights to use water supplies derived
from common law, court decisions, or statutory enactment.
Water Rights
346
[Soil & Water] Using wastewater or reclaimed water from
one application for another application.
Water Reuse
347
[Soil & Water] Is a topographically delineated area which
drains into a reference point in the stream.
Watershed
348
[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
349
[Soil & Water] The collection, treatment,
storage, and distribution of potable water from source to consumer.
Water Supply System
350
[Soil & Water] Imposition of a higher rate on
excessive water use.
Water Surcharge
351
[Soil & Water] Structure across a stream to control or divert the
flow; Device for measuring the flow of water.
Weir
352
[Soil & Water] A pit, hole, or shaft sunk into the earth to tap an
underground source of water.
Well
353
[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
354
[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
355
[Soil & Water] Determination of well yield vs. drawdown
relationship with time.
Well Test
356
[Soil & Water] Discharge rate can be sustained from a well
for some specified period of time.
Well Yield
357
[Soil & Water] The difference between the dryand wet-bulb temperatures.
Wet Bulb Depression
358
[Soil & Water] Numerical quantity to designate the
relation of precipitation or annual runoff for a given year to the long term
average.
Wetness Index
359
[Soil & Water] The average irrigated soil area in a
horizontal plane located at or below the emitter.
Wetted Area
360
[Soil & Water] Diameter of the wetted circle created
by a single sprinkler head.
Wetted Diameter
361
[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
362
[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
363
[Soil & Water] Detachment, transportation, and
deposition of soil by the action of wind.
Wind Erosion
364
[Soil & Water] A means of measuring wind velocity with
an accuracy of ± 3km/h (± 2mph)
Wind Velocity
365
[Soil & Water] Detachment, transportation, and
deposition of soil by the action of wind.
Wind Erosion
366
[Soil & Water] Earth embankment having sections
such as cores and diaphragms of varying permeability to control
seepage.
Zone Embankment
367
[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
