On a globe the shapes of continents and oceans are accurate, but it is very small and cannot show detail. A geographic map shows the Earth’s surface on a flat sheet, reduced and drawn with conventional signs; when a curved surface is flattened, errors appear: islands and seas near the poles look larger than they really are. Maps are physical-geographic (relief, minerals, soils, vegetation, climate, natural zones), political (countries, regions) and economic-social types. Maps showing one particular theme are thematic; maps showing relief, rivers, lakes and cities in general are general-geographic (physical) maps. Relief is coloured by the elevation scale: 0–200 m green, 200–500 m yellow, and higher land brown. Arrows show the direction of a sea current or wind; an outline map shows only contours.
Worked examples
On an atlas map a yellow area means hills 200 to 500 m above sea level, while green means lowland up to 200 m.
On a minerals map coal or oil deposits are shown by special symbols, and on a climate map precipitation is shown by colours and numbers.
Class activity
“Map language”: each group copies 5 conventional signs from an atlas into a notebook with their meanings; another group guesses them like riddles.
Practice
1
How is a map more convenient than a globe, and what is its drawback?
Convenient: the whole Earth or a part of it appears flat and detailed; drawback: showing a curved surface flat causes errors in area and direction.
2
Which maps are physical-geographic: relief, political, soil, climate?
Relief, soil and climate maps; the political map is a separate type.
3
A place at 350 m is coloured yellow on the elevation scale. How many metres does the yellow band (from 200 to 500 m) span?
300
4
Why are rivers and mountains not much emphasised on a political map?
Because the theme of that map is countries and administrative divisions; nature features are mainly on physical maps.