CEA-Vocab Unit 3.4
Key Terms
Key Term
Angle of Repose
Backsight
Bench Mark (BM)
Closure Error
Coarse Grained Soil
Construction Survey
Control Survey
Datum
Design Storm
Detention Pond (Dry
Pond)
Differential Leveling
Duration
Egress
Elevation
Field Notes
Fine Grained Soil
Definition
The maximum angle of a stable slope of a granular material
determined by friction, cohesion, and the shapes of the soil
particles.
The reading on a rod held at a point of known or assumed
elevation.
A relatively permanent object, natural or artificial, bearing a
marked point whose elevation above or below the adopted
datum is known or assumed.
The difference between a measured or calculated elevation
and the true or established elevation.
Soil in which 50 percent or more, by weight, of the soil is
retained on the Number 200 sieve. In other words, 50
percent or more of the sample is composed of sand and/or
gravel.
A land survey that provides points and elevations for
building civil engineering projects. Often called engineering
survey.
Survey that establishes a network of horizontal and vertical
monuments that serve as a reference framework for other
surveys.
Any surface to which elevations are referred (for example,
mean sea level).
A selected storm event, described in terms of the probability
of occurring once within a given number of years, for which
drainage or flood control improvements are designed and
built.
A pond that collects storm water, temporarily stores, and
then slowly releases the water into the municipal storm
water system.
The process of determining the difference in height between
a plane of sight and a point.
The period of time over which rain is measured. For
example in the case of annual rainfall measurements, the
duration is one year.
Exit or a way out.
The vertical distance from a datum to a point or object.
A complete record of all measurements made during the
survey with sketches and narration, where necessary, to
clarify the notes.
Soil in which more than 50 percent, by weight, of the soil
passes the Number 200 sieve. In other words, more than 50
percent of the soil is composed of silt and/or clay.
Finish Grade
The final elevation of the ground surface after excavating or
filling.
Foresight
The reading on a rod held at a point whose elevation is to
be determined.
Geodetic Survey
Surveys to determine relative positions of widely spaced
points which require consideration of the size and shape of
the Earth.
Grading
The process of changing the topography of a property for a
purpose.
Height of Instrument
The vertical distance from the datum to the line of sight of
the instrument.
Impervious
Incapable of being penetrated.
Ingress
Entrance or means to enter.
Initial Point
The starting point for a survey.
Land Surveying
The science of determining relative positions of points on or
near the Earth’s surface.
Liquid Limit
The minimum moisture content, expressed as a percentage
of the oven dry soil weight, at which the soil will begin to
flow when subjected to a small shearing force. The liquid
limit is determined using a standard liquid limit device.
Low Impact Development A storm water management approach that uses green
space, native landscaping, and techniques that mimic a
site’s pre-development water cycle.
Plane Survey
Surveys for which the curvature of the Earth is ignored and
measurements are treated as if taken on a plane surface.
Plastic Limit
The minimum moisture content at which the soil can be
rolled into a thread one-eighth of an inch in diameter without
crumbling and is determined by trial and error.
Plasticity Index
The difference between the liquid limit and the plastic limit.
Poorly Graded
A soil that does not contain a good representation of all
particle sizes. A poorly graded soil may contain a narrow
range of particle sizes (uniformly graded) or may not contain
one or more ranges of particle sizes (gap graded).
Property Survey
A land survey that establishes property corners, boundaries,
and areas of land parcels. Also called land surveys,
cadastral surveys, and boundary surveys.
Rainfall Intensity
The ratio of the total amount of rain (rainfall depth) falling
during a given period to the duration of the period.
Retention Pond (Wet
A permanent on-site pond used to manage storm water in
Pond)
which pollutants are allowed to settle out or be removed by
biological activity.
Return Period
Rod Intercept
Runoff Coefficient
Stadia
Storm Water Wetlands
Topographic Survey
Well Graded
The length of time, on average, over which an event (or an
event of greater magnitude) is expected to occur not more
than one time. For example, a Category 3 hurricane may
have a return period of 100 years, which means that a
Category 3 hurricane (or stronger) is expected to occur no
more than one time, on average, within one hundred years.
The difference between the rod readings at the stadia wires.
A number that indicates the portion of rainwater that will be
discharged by a particular surface.
Two horizontal cross wires that are equidistant from the
center crosshair in the sight.
A permanent shallow pool of diverted rainwater that
incorporates wetland plants. Pollutants are removed through
settling and biological activity.
A land survey used to prepare maps showing location of
natural and man-made features and elevations of points on
the ground.
A soil that displays a good representation of all particle
sizes. For instance, well-graded sand will contain a fairly
even distribution of coarse, medium, and fine sand.