USE OF

MAPS

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WHAT IS A MAP?

• A map is a representation of Earth’s features drawn on a flat surface.

• Unlike Photographs, maps cannot show what the land actually looks like.

• Maps use symbols and colours to represent features of an area

PARTS OF A MAP

1.Basic Features of a Map

** If a map does not provide direction, assume that the top of the map is north.

PARTS OF A MAP2 . S C A L E :

A M A P W I L L V A R Y A C C O R D I N G T O T H E A M O U N T O F D E T A I L R E Q U I R E D . T H E Y A R E C L A S S I F I E D A C C O R D I N G T O T W O G E N E R A L C A T E G O R I E S

a. Large –scale: Show a large amount of detail of small areas scales of 1:50, 000 and 1:25, 000 or less are large scale maps. Used to show detailed information about a small area for such things as residential planning, hiking and military purposes.

b. Small-scale: Show a small amount of detail of large area. Scales of 1:25, 000 and 1:150, 000 or more are small scale maps. Used to show general details such as political, physical and economic information.

MAP PROJECTION

• When the features of a globe are transformed onto a flat surface.

• Certain characteristics make this useful for specific purposes.

• Each one contains distortions such as enlarging some areas and shrinking others, or providing inaccurate direction

• Remember, what you see on a map is not, and cannot be, a true representation of Earth!

• Equal Area Projection:• Allow maps to show the correct size of countries in relation to one

another.

We will look at three different types of maps1. Mercator2. Robinson

3. Winkel-Tripel

MAP PROJECTION – MERCATOR PROJECTION

The Mercator projection creates increasing distortions of size as you move away from the equator.

As you get closer to the poles the distortion becomes severe.

Cartographers refer to the inability to compare size on a Mercator projection as “The Greenland Problem."

Greenland appears to be the same size as Africa, yet Africa's land mass is actually fourteen times larger.

Because the Mercator distorts size so much at the poles it is common to crop Antarctica off the map.

This practice results in the Northern Hemisphere appearing much larger than it really is.

Typically, the cropping technique results in a map showing the equator about 60% of the way down the map, diminishing the size and importance of the developing countries.

MAP PROJECTION – ROBINSON PROJECTIONS

The Robinson projection was developed by Arthur H. Robinson, a professor and the University of Wisconsin, in 1963.

It was the first major map projection to be commissioned by a large private corporation; Rand McNally hired Robinson to develop the projection because they were not satisfied with the ability of existing projections .

Rand McNally still makes extensive use of the Robinson projection, and the National Geographic Society uses it as well (although the Society seems to be using the projection a bit less frequently now than it did in the 1980s).

Robinson called this the orthophanic projection (which means "right appearing"), but this name never caught on.

Sometimes refereed to as the Pseudocylindrical Projection with Pole Line, which is highly descriptive (the "pole line" bit comes from the fact that the North and South Poles on a Robinson projection are shown as lines and not points), though, Robinson projection is unquestionably the name of choice

MAP PROJECTION – WINKEL-TRIPEL PROJECTION

The Winkel Tripel projection was developed in 1921 by Oswald Winkel (1873 - 1953).

Contrary to popular belief, Tripel is not somebody's name; it is a German term meaning a combination of three elements.

Winkel choose the name Tripel because he had developed a compromise projection; it does not eliminate area, direction or distance distortions; rather, it tries to minimize the sum of all three.

Prior to 1998, the Winkel Tripel projection was not considered particularly exceptional.

However, in 1998 the National Geographic Society announced that it was adopting the Winkel Tripel as its standard projection for maps of the entire world.

As a result of this announcement, interest in the Winkel Tripel projection has skyrocketed over the last few years.

TYPES OF MAPS

General-purpose maps: provide many types of information on one map. Most atlas maps, wall maps, and road maps fall into this category. Some of the things that might be shown on general-purpose maps are:

  Bodies of water Roads Railway lines Parks Elevations Towns and cities

 

When all of these features are combined, a general-purpose map is created. These maps allow a broad understanding of the location and features of an area.

TYPES OF MAPS

Thematic Maps: When you require specific information about a place. These maps are designed to show information on one particular topic. Tend to be easy to understand.

(page 23 figure 2-7)

 

Topographic Maps: use symbols to show a variety of features. Used if you want to examine the characteristics of a small area of the Earth’s surface in detail.

(page 23 figure 2-8, look at page 24 & 25)

Questions to Answer on page 26:

Check your Understanding: #1, 2, 5,