using a topographic map. a relief map with contour lines

Using A Topographic Map

A Relief Map With Contour Lines

A

TOPOGRAPH

I

C

MAP

What are they?• Topographic maps are an invaluable tool for

everyone from hikers and campers to county planners and emergency response teams.

• These maps are used by planners, engineers, outdoor enthusiasts, and many others rely on these to accurately depict the land surface.

• During natural disasters, such a hurricanes, floods, landslides, and earthquakes large numbers of topographic maps are used by emergency response agencies and to assist recovery. 

Map Scales• A ratio of distance on a map to the actual

distance on earth– Ex. 1:24,000 means that one unit of

measurement on the map will equal 24,000 of those units on earth

– May also be represented graphically:

U.S.G.S. Maps• The United States Geological Survey

produces topographic maps of the entire country

These maps are called quadrangles and they come in different sizes

1:250,000

1:100,000

1:24,000

As we look at a smaller area of the earth, we can put more details on the map so a 7.5’ quadrangle will be more detailed.

• Most USGS map series divide the United States into quadrangles bounded by two lines of latitude and two lines of longitude. For example, a 7.5-minute map shows an area that spans 7.5 minutes of latitude and 7.5 minutes of longitude

New York 10 of Latitude by 20 of Longitude

Long Island 7.5’ by 7.5’

Map Symbols

Are universal so that everyone everywhere can read the map without a

individual legend

Vegetation is green

Water is blue

Each road type has it’s own symbol

Secondary Road

Ice

Rail Road

Orc

hard

Use the Map Symbol Key in your text book to see all the acceptable colors and symbols

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