0135090520_ppt20

C H A P T E R T W E N T Y

LANDFORM

DRAWINGS

2

Technical Drawing with Engineering Graphics, 14/e

Giesecke, Hill, Spencer, Dygdon, Novak, Lockhart, Goodman

© 2012, 2009, 2003, Pearson Higher Education,

Upper Saddle River, NJ 07458. • All Rights Reserved.

OBJECTIVES

1. Read and draw a plat, topographic contour map, street contour

map, and highway plan and profile.

2. Read the elevation of a tract of land using contour lines.

3. Identify the scale and compass orientation of a topographic map

.

4. Read and notate property boundaries on a land survey map.

5. Create a profile map from contour lines.

3





LANDFORM DRAWINGS Terms

• Plat

• Traverse

• Elevations

• Datum

• Profile

• Contours

• Hatchures

• Monuments

• Cartography

4





Map Types

• Topographic

• Hydrographic

• Cadastral

• Military

• Nautical

• Aeronautical

• Engineering

• Landscape

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Topographical Drawing

Topographic drawings use orthographic projection, just as technical

drawings do, in which the direction of sight is perpendicular to the plane of the

map.

6





GETTING INFORMATION FOR MAPSElectronic Survey Instruments

Trimbal S6 Total Station. (Courtesy

of Trimble Navigation Limited.)

A survey is the basis of

all maps and

topographic drawings.

Several surveying

methods are used to

obtain the information

necessary to make a

map.

Most surveys use

electronic survey

instruments to

measure distances

and angles.

Electronic

instruments measure

distances of up to 4 mi

with accuracies

from .01' to .03', which

is more than sufficient

for topographic

surveying

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Global positioning system (GPS)

Global positioning system (GPS) receivers

calculate the receiver’s position by interpreting

data received from four different satellites

concurrently through a process called

Trilateration (which is similar to

triangulation).

Twenty-four satellites orbit the earth in

Twenty-four satellites orbit the earth in a

pattern called a GPS satellite constellation

GPS Satellite Constellation. (Courtesy of Aerospace

Corporation (http://www.aero.org).)

8





SYMBOLS

Various natural and human-

made features are designated

by special symbols.

Timely Map Symbol Template

(Courtesy of Timely Products Co., Inc.)

Templates can save time in

hand drawing map symbols.

9





BEARINGSThe bearing of a line is its angle from magnetic north. Bearings are listed

by referencing the angle the line makes departing from either the north or the

south toward either the east or west.

Bearings Specify an Angle and Direction from North or South toward East or West. The bearing N 44°52'

E means that if you were at point A facing north, you would turn 44°52' toward the east to face point B.

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CONTOURS

Contours are map lines showing points of equal ground elevation.

Topographic Map with Contours and Satellite Imagery. (Courtesy of TopoZone

at www.topozone.com)

Same Elevation

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Interpolating Elevation DataLocations of points on contour lines are determined by interpolation.

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3D Terrain Models

Electronic survey data containing elevations can

often be downloaded directly to 3D terrain

modeling software. Most of these software

solutions produce a surface model of the terrain

formed of many small triangles and are thus

called a Triangulated Irregular Network, or

TIN. Contours, profiles, cut-and-fill

calculations, and other information

can be generated semiautomatically

from the TIN.

TIN 3D Terrain Model Produced

in Autodesk Civil 3D 2008. (Used

with permission of Autodesk, Inc. ©

2006–2007. All rights reserved.)

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CITY MAPS

A City Plan for Location of a New Road Project

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Subdivisions

Plats

Maps perform an

important function for

those who plan the

layout of lots and

streets.

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Utilities and Other InformationUtilities and other information are often referenced to locations from subdivision plats. A

subdivision plat showing the locations of above-ground and underground power is shown

below…

Above-ground and underground power is located from subdivision plats. (Courtesy of Golden

Valley Electric Association.)

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Landscape Drawings

A Landscape Drawing. (Courtesy of Hispanic Business, Inc.)

Maps have a definite use in landscape planning…

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STRUCTURE LOCATION PLANSMaps are used to plan construction projects to locate construction features so they fit

the topography of the area.

Plan for Hoover Dam (From Treatise on Dams. Courtesy of U.S. Dept. of

the Interior, Bureau of Reclamation.)

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HIGHWAY PLANSBefore highway construction starts, it is necessary to plan the horizontal and vertical location

and alignments. Commonly, both the plan view and profile are drawn on the same sheet.

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UNITED STATES MAPSMaps of the United States, prepared by the U.S. Coast and Geodetic Survey and the U.S. Geological

Survey, are excellent examples of topographic mapping. Such maps cover large areas, for example a

large scale of 1:62,500, very nearly one mile to the inch.

The National Atlas. Available on the World Wide Web at

http://www.nationalatlas.gov/natlas/Natlasstart.asp.(Courtesy of National Atlas of the United States.)

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CONTOUR MAPS FROM 3D DATACAD software like Autodesk’s Civil 3D allows you to create contour maps by

entering site data.

Autodesk Civil 3D 2008 software provides tools to generate contour maps from survey

data. (Autodesk screen shots reprinted with the permission of Autodesk, Inc.)

Data can even be

downloaded

directly into the CAD

software from a

total station survey

instrument.

Using Civil 3D

software, you can

show point

descriptions, contour

lines, grid lines, and

features such as

bodies of water or

structures and

produce topographic

pictorial drawings.

0135090520_ppt20

Documents

engineering graphics

upper saddle river

pearson higher education

topographic map

profile map

topographic contour

land survey map

technical drawings