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Land Use Surveying
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Date : 6-July-2020
Assignment
Of 2nd semester Midterm Exam
ON
Land Use Surveying
NAME: Muhammad Tahir
ROLL NO. 54
ASSIGNMENT/Paper :Surveying For Midterm Exam
SUBMITTED To: Sir Basit Nadeem
Department of Geography Bahauddin
Zakariya University Multan
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DEFINITION OF SURVEYING
Surveying is the art and science of
determining the relative positions of various
points or stations on the surface of the earth
by measuring the horizontal and
vertical distances_, Angles and taking the
details of these points and by preparing a map
or plan to any scale.
Measurements taken in Horizontal and
Vertical planes
Land Survey:
Land Survey is Also called
TOPOGRAPHICal SURVEY.
A topographic survey or sometimes called as
contour survey is used to
collect data about the elevation of points on a
piece of land and present them as contour
lines on a plot.
Earliest Land Surveyor
Earliest practices of land surveying can date
back to the old civilization of the ancient
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Egyptians around 1400 B.C. They
accomplished the construction of the great
pyramids and waterways using primitive
surveying tools, such as measuring ropes,
plumb bobs, and other gadgets that assisted
them in evaluating a parcel of land. Later, the
Greeks and Romans created the groma which
helped in dividing the land and building new
roads and structures. This instrument was
used to establish straight lines and right
angles.
11th Century
In England in 1086, William the Conqueror
commissioned the Domesday Book, also
known as the Great Survey. This manuscript
held an extensive record of each piece of land
owned, its boundaries, elements on the land,
the landholders and their tenants.
18th Century
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It wasn’t until the late 1700s that
improvements to the earliest form of a
theodolite, consisting of a tripod and
compass, were made. Jesse Ramsden, a
scientific instrument maker, designed and
created a modern version of the theodolite.
He designed it with the dividing engine that
was capable of obtaining measurements and
angles with high accuracy.
19th Century
During the 19th century, land surveying jobs
became prominent. The industrial revolution
caused an increase in the demand of
surveyors because of the rapid expansion in
developments.
Today
Early principles of measurement and
surveying tools continue to be important in
today’s practices. New technologies have
improved the performance of older surveying
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instruments. New tools and methods like 3D
scanning, GPS, and GIS Software have
enhanced the efficiency and effectiveness of
land surveying today.
Types of Land Surveys
Mortgage surveys, also known as title
surveys, are requested by title companies,
banks, and mortgage lenders. They confirm
there has been no trespassing by an adjacent
property owner and that local zoning laws
and building codes are met. They show that
easements remain accessible and provide
other data. Mortgage surveys locate every
detail of a property, including the locations of
the trees.
ALTA/ACSM surveys are typically used for
commercial real estate, showing existing
improvements on a site relative to its
boundaries as you see them on the deed. They
also show improvements, easements,
rights-of-way, zoning classifications,
waterfronts, and much more. ALTA/ACSM
is a comprehensive, and therefore, a rather
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expensive survey. It can take from two weeks
to several months to complete.
Boundary surveys involve field and record
research. They are used to identify and
confirm the corners and boundary lines of a
parcel of land following state law. They may
include easement lines and encroachments.
They can be performed in a few hours
depending on the size of the lot.
Construction surveys stake out features and
structures like roads, utilities, walls, and
buildings within a construction project. The
survey stakes the slope, vertical and
horizontal grading, and an As-built survey.
The staking shows workers the directions for
implementing improvements shown on the
plans.
Location surveys are rather like boundary
surveys but contain more information on
interior improvements. Zoning permits and
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loan applications often require location
surveys.
Site planning surveys combine boundary
surveys and topographic surveys. They are
used to design commercial and industrial
sites, house lots, subdivisions, playgrounds,
and stores, among other things. A site
planning survey may be required for
development permit applications before
construction begins.
Subdivision surveys are what they sound like:
surveys used to divide land into smaller lots,
tracts, or estates. Subdivision surveys are
required by local government agencies to
plan streets, lots, and drainage. You may also
hear it called a partition survey or platting.
The trend for master-planned communities
makes heavy use of subdivision surveys.
Before construction begins, the planning
commission or zoning board must review and
approve the plat map.
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Topographic surveys are performed by
professional civil engineers. They locate
topographic features such as utilities, roads,
watercourses, ditches, embankments, and
contours as well as other improvements such
as fences or walls. They often utilize aerial
photography as well as field methods of
surveying. All natural and man-made features
are located and detailed on the resulting map.
This type of survey may be a requirement of
local or state government agencies.
Topographic surveys are needed when adding
a new structure onto a developed piece of
land. It shows how the property will look
after the new building is complete. It shows
where the property may need to be leveled,
and help plot the surface for work
visualization and planning in three
dimensions.
Purpose of a topographic survey is to
collect survey data about the
natural and man-made features or existing
features on the surface of the
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earth or slightly above or below the earth's
surface.
For example: Trees,
hills, streams, buildings, streets, walkways,
manholes and others)
Use of topographic surveying in
geography:
producing topographic maps
constructing topographic (cross-sectional)
profiles
establishing vertical and horizontal control
for accurately defining locations
General Principles;
1.select a scale in advance; this determines
the plottable error
2.work from the most accurate to the least
accurate methods
3.orient each survey, preferably with respect
to true north
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4.the first stage of surveying is always
establishing horizontal and vertical control:
the distance, direction and difference in
elevation between key fixed points
5.establish a survey plan that includes checks
on accuracy, e.g. redundant points, pacing of
measured distances, surveying between fixed
positions, etc.
Methods Of Land Surveying
Land surveyors work in the office and in the
field. In the field, they use the latest technology
such as high order GPS, Robotic Total Stations
(Theodolites), and aerial and terrestrial scanners
to map an area, making computations and
taking photos as evidence. In the office,
Surveyors then use sophisticated software, such
as Auto-cad to draft plans and map the onsite
measurements. Surveyors work on a diverse
variety of projects from land subdivision and
mining exploration, to tunnel building and
major construction, which means no two days
are the same. They are experts in determining
land size and measurement. They also give
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advice and provide information to guide the
work of engineers, architects and developers.
1.horizontal distance
tachymetry: a rapid optical means of
measuring distance using a telescope with
cross hairs and a stadia rod (one stadium =
about 607 feet)
measuring slopes distance with a tape and
reducing it to horizontal distance using the
cosine of the slope gradient
2.difference in elevation
leveling with a level telescope and a stadia
rod, or
measuring a vertical angles and a slope
distance (height is the product of the distance
and sine of the angle)
Leveling is more accurate since elevation
differences are measured not calculated. Two
readings are taken at each position of the
automatic level: a backsight towards a station
located before the level on the traverse and a
foresight to the next station on the traverse.
Thus the stadia rod occupies two stations,
before and after the level on the survey. The
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difference in elevation between successive
stations is the difference between the
backsight and the foresight read from the
stadia rod. For each position of the level, the
lengths of the foresights and backsights
should be approximately the same since
accuracy is a function of the distance of a
sighting. The level operator should anticipate
the distance to the next station and set up the
level midway along this distance (note: the
distance that can be sighted decreases with
increase in slope, since the stadia rod will
disappear above or below the level line of
sight). The lengths of backsight and foresight
can be paced by the rod person or measured
by the interval between the upper and lower
cross hairs (tachymetry).
3.direction
horizontal angle measured with a compass
precise measuring devices use vernier scales
direction is expressed relative to a reference
line or meridian
true meridian: a north-south line
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magnetic meridian: a line parallel with the
earth's magnetic lines of force
assumed meridian: an arbitrary line
Establishment of Control
In topographical surveying the main reason
for a control survey is to prevent
errors from accumulating. It is the principle
of `working from the whole to the part'.
Importance Of Land Surveying
Land surveying involves measuring and
mapping the world around us using
mathematics, advanced software and
equipment. Surveyors calculate just about
anything in the ground, in the sky or in the
bottom of the sea. Also, polar ice caps are
measured.
Land surveyors are employed both in the
office and in the field. They use the highest
technology in the field, like high-order GPS
and aerial and terrestrial scanners for
mapping, compute and take pictures as
evidence. Surveyors are employed on a
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variety of projects ranging from land
development and mining discovery to tunnel
building and major construction, ensuring
that no two days are the same. They are
experts in measuring and determining land
size. They also provide advice and
information to help designers, architects and
developers in their work.