Basic Map Knowledge

For Orienteering

What is a map?

• A symbolic picture of an area from up above• It usually has a particular point of view, an

audience, and a specific purpose

The Map concept

• View from above• Conveys information• Represents SOME of

the features

• Those that are navigationally useful

The Map concept

• Uses a symbolic language

– Like Signs – No Parking

– Like Sheet Music

Types of MapsTypes of Maps

• Road Maps• Park Maps• Nautical• Aeronautical• Cave• Battlefield• Political• Geological

Topographical Maps

• x

Contours

• Horizontal Slices through the earth

• Like a layer cake

• Shows the lay of the land.

Contour Interval

Vertical Distance between contour lines

Map Symbols

• USGS Maps

• Orienteering Maps

Map Symbols• The symbols, Colors, and

shapes are the language of mapping

• Mapping (Cartography) is both a science and an art– Science – uses agreed

upon conventions – Art – allows for style,

emphasis, and general differences in maps

Map Colors

• 5 Colors• Yellow• Green• Brown• Blue• Black

• Plus the white of the paper

• And a course overlay in Red or Purple

White: Open Forest

Yellow: Open Land

Green: Thicker Vegetation

Brown: Shape of the Land

Contour lines represent elevation in the landscape.

Blue: Water Features

Black: Man-Made & Rock

Maping Symbols

Orienteering Cincinnati, © 2005

Contours

• Common shapes– Reentrant (v-shape, low ground, points up hill)– Spur (u-shape, high ground)– Ridge– Saddle )(– Knoll

• enclosed circle: top of a hill• just a dot small hill

Orienteering Cincinnati, © 2005

Contours

Re-entrant• probably the most puzzling term encountered by the

beginning orienteer• kind of valley closed at one end • a re-entrant is an "entering" of the land into the hill

shallow deep

Orienteering Cincinnati, © 2005

Contours

Spur • Is the opposite of a re-entrant• A projection or "nose" rising from the surrounding

ground.

Description sheet symbol

Map symbols

Orienteering Cincinnati, © 2005

Contours

Ridge • The highest point running from knoll to knoll.• The best place to travel• Easiest running

Orienteering Cincinnati, © 2005

Contours

Saddle • The low point between two higher points..

Description sheet symbol

Map symbol

Orienteering Cincinnati, © 2005

Contours

Hills & knolls• Dot knoll: A small obvious mound.

• Hill: an enclosed contour line.

Knoll

Map symbolsDescription sheet symbol

Hill

Both

Orienteering Cincinnati, © 2005

Contours

• Telling up from down– Closed circles are the tops of hills– Blue lines are steams and are at the bottom of hills.– Reentrants point up from streams to hilltops – Spurs point down from hill to streams and valleys

Orienteering Cincinnati, © 2005

Contours

• Telling up from down

The re-entrant and the spurs are very similar.Are they fat spurs and deep reentrants…Or are they wide shallow reentrants with long skinny spurs?

Orienteering Cincinnati, © 2005

Contours

• Telling up from down

You will unusually be able to find a stream and/or a knoll someplace near on the map.

The streams are the lowest points.The knolls are the highest.

Trace the highs and lows to the area of interest.

Parts of a map

• Title• Scale• Legend – key• Contour

interval• Map body• Compass rose

- N↑• Magnetic

north lines at scaled intervals

Additional information on map

• Location – area map

• Mapping credits• Update info &

printing dates• Copyrights• Contact info• Access

permissions• Logos• Additional

boiler plate info

Overprint on map

• Course • Description

sheet

Scale on Map

• Common USGS map scales– 1:24000 1:62500 1:250000

• Common orienteering map scales – 1:15000 1:10000 1:5000 -

1:7500 1:4000 – Nominally called 1:15 1:10 1:5

Scale

• Compare 2 scales