COMPONENTS OF MAPS

COMPONENTS OF MAPS

Topical vocabulary:

title (of a map)	название (карты)
to represent	обозначать (на карте)
hydrography	гидрография
vegetation	растительность
relief	рельеф
latitude	широта
longitude	долгота
to measure distances	измерять расстояния
legend (key)	легенда карты; пояснения за рамкой карты;
legend of symbols	таблица условных знаков
grid	сетка (координат)
observatory	обсерватория
map projection	картографическая проекция
cylindrical map projection	цилиндрическая проекция
conical map projection	коническая проекция
azimuthal map projection	азимутальная проекция
Mercator map projection	прямая равноугольная цилиндрическая проекция Меркатора
to devise	разрабатывать
distortion	искажение
scale	масштаб

Text

Despite their variety, all maps have similar components. These include a title; a legend or key; a direction indicator; and a scale.

The title of a map identifies what the map is about and what parts of the earth it shows. The title of some maps includes a date. Dates are useful on maps showing features that change over time. A map with the title “Distribution of Population in France: 1920”, for example, should not be used when looking for information of the present population of France.

A legend or keyexplains the meaning of colours and symbols used on a map. A map with areas shown in green, red and blue might be misunderstood unless the user knows what the green, red and blue represent (blue for hydrography, green for vegetation, red for man-made features and brown – for relief). The legend also explains the meaning of symbols used on a map, such as stars for capital cities.

Every map should have a direction indicator.One such indicator is an arrow that points north. A different way to find directions on a map is to study the parallels and meridians. East and west directions follow parallels, or lines of latitude. North and south directions follow meridians, or lines of longitude. Parallels and meridians cross each other to form an imaginary grid over the earth. Because each degree can be broken into 60 minutes (`) and each minute into 60 seconds (``), this grid can be used to fix the precise location of any point on the earth’ surface.

The most important longitude is called the Greenwich Meridian, because it passes through a place called Greenwich in London where there is a famous observatory. The longitude of Greenwich meridian is 0 degrees. At Greenwich local time is called Greenwich Mean Time (GMT). All places on the same meridian have the same local time. When it is noon at a given meridian, it is after noon or post meridiem (p.m.) at places which lie to the east of it. This is because the earth rotates from west to east. At the same time the sun will be before noon or ante meridiem (a.m.) at places lying to the west.

Maps scales and projections.A map scale provides statistical information used to measure distances on a map. While maps have similar components, they do not always show areas of the world in exactly the same way. The size and shape of North America, for example, may look somewhat different on two different maps. The differences occur because the two maps use different map projections, or methods by which the features of the earth’s curved surface are transferred onto a flat map.

A great variety of map projections has been devised to provide for the various properties that may be desired in maps. A projection is a systematic method of drawing the Earth’s meridians and parallels on a flat surface. Most types of projection can be grouped according to their geometric derivation as cylindrical, conic or azimuthal.

No matter which projection is used, every map has some distortions that are inevitable in the process of illustrating the earth’s spherical surface on a flat map.

Post-reading exercises:

Exercise 1. Answer the questions using information from the text:

1) What are components of a map?

2) What does the title identify?

3) What does the legend explain?

4) What do blue, green and brown colours represent on the map?

5) What is a direction indicator?

6) What is GMT?

7) What information does the scale provide?

8) Why have maps got distortions?

Exercise 2. Retell the text “COMPONENTS OF MAPS” using the questions above.

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