## Definition of a map

A map is a representation of the earth or part of the earth on a flat surface or globe.

Parts of the earth can be a school, village, district, province, a country or a continent. Features like hills, valleys, rivers, and lakes can also be represented on a map.

A map is different from a picture.

A picture shows things as they are on the ground.

Some maps show a very large area, like this map of the entire Earth;

And other maps show very small areas, like in this example;

## Elements of a map

Elements of a map are also called marginal information. Marginal information is the additional information used to explain symbols found on a map.

• Title: This is the heading of a map. It gives the name of the area shown on the map.
• Frame: This is a square or rectangle drawn to enclose a map.

• Key: This is a list that gives the meanings of the symbols, lines, colors, and letters used on a map. Their meanings are written next to them. The key is usually found at the bottom, left or right side of the map.
• Scale: This is a measure used to enlarge or reduce measurements on a map. Scales are used to reduce actual distances on the ground so that they can fit on paper. A scale is usually drawn at the bottom of the map. It usually looks like the image below.

• Compass direction: A compass always shows the North point. The North point helps us to locate positions of places on a map.

• Map reading is the study of a map in order to have an understanding of what it represents.

• Map interpretation is the explanation of the meaning and importance of a map.

Title, key, frame, scale, and compass direction are used to read and interpret a map.

The key is used in reading and interpreting a map. It contains symbols of features represented on a map and their meanings. We, therefore, need to study the key carefully when reading or interpreting a map.

### a) Colours

Different colours are used on maps to represent different features. The image below gives some examples of what different colours may represent on a map.

#### Using Compass Points

Direction of places on a map can be shown using a compass. A compass is always drawn on the map. The North direction is always shown on the compass from which other directions are identified.

The four main points of a compass are called cardinal points - East, West, North and South. Cardinal points are divided into eight points of a compass, which is also subdivided into sixteen points of a compass as shown below.

#### Using symbols

Every map has a key in which all the symbols used on it are explained. Symbols vary from one map to another. We, therefore, must study the key carefully. Below is a simple example of a key.

### b) Relief

Using symbols, one can describe different relief features found on maps. By studying the key, one can also describe the general relief of an area.

i) The presence of many hills in an area being represented shows that the area is hilly. The highest point on the map can be obtained by studying the height of hills shown on the map.

ii) The presence of swamps may indicate that the area is generally flat. We should not assume that all swamps are found in lowland areas. Some swamps are found in flat areas in the highlands. By using the direction of flow of rivers, we can tell to which direction the land is sloping.

iii) Crops can indicate whether a place is within highland or lowland areas. For example, sugar cane and cotton grow in lowland areas where the climate is generally hot. Tea, coffee and pyrethrum are mainly grown in highland areas.

iv) The presence of forests may indicate that a place is a highland area. However, this is not always the case as some forests are found in lowland areas along the Coast,where rainfall is high and temperature is high.

v) The presence of volcanic soil may show that the area is a highland.

vi) Lakes and oceans are found in lowland areas.

### c) Vegetation and climate

Vegetation features are often shown using green colour on maps.

i) As we have seen, the presence of forests may be used to indicate that a place receives high rainfall. Since most of forests are found on highlands, they may show that the area experiences low temperatures.

ii) The presence of scrub or grassland may indicate that the area receives low rainfall.

iii) Lack of agricultural activities may indicate that the climate or soil is not good for crop farming.

iv) Very low population may be a sign that climate, soils or land surface are unsuitable for crop farming or for building homes.

### d) Drainage

Drainage refers to water features and how they are distributed. They include oceans, seas, oases, rivers, swamps, waterholes, boreholes,lakes, dams and springs. On maps, they are represented using different shades of blue.

i) Presence of many rivers especially if they originate from one particular area may indicate that the area receives high rainfall.

ii) The direction of tributaries as they join the main river can be used to identify the main direction of flow of the river.

iii) Presence of boreholes and oases shows that the area receives little rainfall.

iv) Drainage system is also used to show relief of the land.

### e) Economic Activities

By studying the various symbols shown on the map, it is possible to tell peoples' economic activities. Some examples are shown below:

1. Trade - Towns, shops, markets.

2. Transport and communication - All-weather roads, railways, airports and airstrips, dry weather roads, ports, post office, telephone lines,

3. Industry - Factory, mills, industrial plants, power stations

4. Crop farming - Plantations and farms, flour mills, irrigation channels, processing factory for a plant product

5. Livestock farming - Cattle dips, ranches, creameries, slaughter houses,

6. Mining - mineral works, quarries, mines,

7. Fishing - Fish traps, fishing villages, fish processing plant, fish ponds,

N/B The presence of rivers or lakes may not necessarily mean that fishing takes place.

8. Tourism - Museums, historical sites, game reserves, game parks, animal orphanages, hotels and beaches.

9. Forestry - Saw mills

10. Religion - Mosque, church, temple, shrine

11. Medical - Dispensary, hospital, health centre, clinic

12. Education - Schools

### f) Settlement

On most maps, settlements are shown using dots of different shapes and sizes. For example:

1. Small round dots indicate huts while small squares indicate permanent buildings.

2. Areas with low population or settlement tend to have few dots scattered all over the map. Areas with crowded settlements will be indicated by the presence of many dots clustered together.

3. By studying the arrangement of dots, we can tell the type of settlement patterns in an area.

4. Areas with low population distribution show that the areas may be experiencing low rainfall or the areas may be having infertile soils.

• Boundaries of districts, locations, and sub-locations may be shown using different lines. The meanings of these lines are explained in the key on the map.
• Administration services may be shown by the presence of a chief’s camp, DO’s or DC’s Office.
• Security may be shown using the presence of a police station, a prison or a court.

## Direction of places using compass points

The direction of places on a map can be shown using a compass. A compass is always drawn on the map. The North direction is always shown on the compass from which other directions are identified.

The four main points of a compass are called cardinal points.

Cardinal points include; East, West, North, and South. Cardinal points are divided into eight points of a compass, which is also subdivided into sixteen points of a compass.

### Measuring Distance on a Map

Distance on a map can either be straight or curved. Distance on a straight line can be measured using;

1. A ruler
2. A straight edge of a paper
3. A pair of dividers

#### Using a Ruler

To find the distance between two points using a ruler, place the ruler along the line. Read the measurement on the ruler then place the ruler along the linear scale to read the actual distance.

#### Using a Pair of Dividers

To measure the distance between points T and U in Fig. 1.6 below using a pair of dividers, follow the following steps:

• Open out the pair of dividers.
• Let one point rest at T while the other rests at U.
• Transfer the dividers onto the linear scale. Make sure that you do not open out or close the dividers.
• Read the distance from the linear scale.

If the distance to be measured is longer than the dividers can measure, then a shorter distance can be measured a number of times.

This is done by setting the divider at a shorter distance, and then rotating it until the whole distance is covered.

#### How to measure curved or irregular distances

This can be done using the following;

2. A sheet of paper

#### Using a Piece of Thread

To measure an irregular distance between points A and B using a piece of thread, carefully lay the thread along the line as shown below.

#### Using an Edge of Paper

A piece of paper can be used to measure the length of an irregular distance along a road, railway or river. This is done in the following way;

• Find a straight edge of a paper.
• Using a pencil, mark off the straight sections of the distance to be measured.
• To measure the distance between two points, place the paper at the start and mark off the point on the sheet of paper. Slowly move the paper along the line, marking off the straight sections until the end point is reached.
• Transfer the marked paper on to the linear scale. Read off the distance in kilometres.

The diagrams below show how to measure irregular distance using a sheet of paper, systematically.

### Calculating Area of a Map

Shapes of surfaces on a map can either be regular or irregular. Below is how to calculate the area of regular and irregular shapes.

#### Calculating areas of regular shapes

To calculate the area of regular shapes like rectangles, squares or right-angled triangles, we apply the formula used in mathematics. The scale should be used in working out the length and width before they are multiplied. The answer is given in square kilometers.

#### Calculating Areas of Irregular Shapes

Most areas of surfaces like the island in Fig. 1.13 (shown on the next page) are irregular in shape. Therefore, the area can only be estimated.

To work out the area, the following steps are followed:

1. Divide the map into grids or squares of 1 cm by 1 cm since the scale of the map is 1 cm represents 1 km; this means that each square on the map represents 1 square km on land.
2. Count all the full squares covered by the island. (15 full squares)
3. Count all the partly covered squares, however small, as half squares. Add all of them up and multiply the figure by half 23 x 1/2 = 11 1/2 sq.km
4. Add up all the full squares and the figure obtained from the part squares. According to Fig. 1.13, the area of the island is 15 + 11 + 1/2 = 26 1/2 sq. km.

A diagram of an irregular map is shown below, indicating the full and partly covered squares which are shaded differently.

Watch this video

### Sources

• classroom by Public Domain Images used under CC_BY-SA
• map by the place at innsbrook used under CC_BY-SA
• big_map by WeShare used under CC_BY-SA
• small_map by Edited used under CC_BY-SA
• Labelled-map by Slide player used under CC_BY-SA
• scale by Geogesplace used under CC_BY-SA
• map-interpretation by eLimu used under CC_BY-SA
• map-reading by The Atlantic used under CC_BY-SA
• colours by eLimu used under CC_BY-SA
• compass_rose by Pinterest used under CC_BY-SA
• 054e70db-defe-4f65-b3ad-4377da227f7c by elimu used under CC_BY-SA
• 913c5f83-f8b7-4cdf-9e0d-a24ef04bf441 by elimu used under CC_BY-SA
• map-key by da template used under CC_BY-SA
• settlement by City-data.com used under CC_BY-SA
• 6df14a77-2281-4244-98d1-3b0dfcd5c504 by elimu used under CC_BY-SA
• measuring_distance_by_ruler by eLimu used under CC_BY-SA
• SST.1.23 by Unknown used under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
• SST.1.25 by Edited used under CC_BY-SA
• measure_with_thread by Edited used under CC_BY-SA
• SST.1.26 by Unknown used under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License