����ý

Atlases provide maps on global and national scales. Some atlas maps show physical features, whilst others show human features.

Physical maps

Physical maps show natural features such as mountains, lowlands, major rivers, seas, oceans and ecosystems like deserts and rainforests on a global scale. On a national scale, physical maps show relief and drainage features, such as rivers.

Some maps show physical features that are experienced rather than seen. Examples of this are average temperature and rainfall maps.

Human and political maps

Political maps show country boundaries and major cities. Human maps show features that people have created. Examples of these are population distribution, migration flows, transport routes and settlement layout.

Some maps show human features that are experienced rather than seen. Examples of this are life expectancy, standard of living or even measures of world happiness.

Direction

Often, maps have a direction arrow to show which way is north. North is at the top of the globe and south is at the bottom. East is to the right and west is to the left. Compass points in between these four are shown as combinations, eg the point in between north and east is called north-east. If the point is slightly closer to the east, it is called east-north-east.

When describing direction, we always state the direction we are coming from.

Latitude and longitude

Latitude and longitude enable users to find locations on atlases.

• As the Earth is a sphere, lines of latitude and longitude are measured using degrees of a circle.

• Lines of latitude are horizontal lines running from east to west. The Equator is a line of latitude that lies at 0°. Lines above this are shown as °N (north) and lines below this are shown as °S (south).

• Lines of longitude are vertical lines which run from north to south. The Prime or Greenwich Meridian in London is a line of longitude at 0°. Lines to the right of this are shown as °E (east) and lines to the left of this are shown as °W (west).

Latitude is shown first and longitude is shown second, eg. Manchester in the UK is at 53.5°N, 2.2°W.

The Ordnance Survey (OS) is the mapping agency for Great Britain. It creates up-to-date paper and digital maps for individuals and businesses to use.

Using a key

OS maps show physical and human features as symbols. This makes the maps easier to read. Each OS map has a key to show what the symbols mean.

Scale and distance

Maps show objects as being much smaller than they are in real life. The relationship between the features on the map to the real size on the ground is called the scale. Scale is shown as a ratio, eg 1:25,000 means that 1 cm on a map represents 25,000 cm or 250 m in real life.

OS maps come in different scales:

• Large-scale maps - 1:1,250, 1:2,500 and 1:10,000. Features appear larger on the map. This may be used for individual towns and cities.
• Small-scale - 1:25,000, 1:50,000 and 1:100,000. Features appear smaller on the map. This may be used to show larger areas or regions.

Four and six-figure grid references

Grid references accurately locate places on a map. Every OS map has a grid, which is shown using faint blue lines. The lines across the bottom of the map are called eastings as they travel towards the east. The lines up the side of the map are called northings as they travel towards the north.

Four-figure grid references locate a place or object within a grid square. Four-figure grid references are found as follows:

1. First, write the eastings number of the bottom left corner of the square (eastings are found along the bottom of the map). The number will have two digits eg 13.

2. Then, write the northings number of the bottom left corner of the square (northings are found along the side of the map). The number will consist of another two digits giving a total of four, hence the name four figure grid reference.

Six-figure grid references locate a place or object within a specific part of a grid square. Six-figure grid references are found as follows:

1. Write the four figure eastings number, but then add a third number to show how many tenths of the way across the grid square the place or object lies.

2. Write the four figure northings number, but then add a third number to show how many tenths of the way up the grid square the place or object lies.

Contours and spot heights

On a map, height is shown in metres above sea level. Spot heights show the height of a particular point on the map.

Contour lines are added to a map to show height and gradient. On OS maps they are shown as thin orange or brown lines, some of which have the land height written on them. The lines join areas of equal height:

• Contour lines that are close together show land that increases or decreases in height quickly. This is steep land.

• Contour lines that are far apart show land that increases or decreases in height slowly. This land is gently sloping.

We can use contour lines to create cross-section diagrams of landscapes. This helps to match contour lines on the map to landscape features in real life, eg hills, valleys and spurs of land.

Describing a map

Depending on the purpose of the map, it will show different features.

• Human maps: will focus on features made by people – roads, buildings, settlements, quarries, farmhouses.
• Physical maps: emphasise the physical features like altitude, rainfall, bogs, natural vegetation and so on.

Describing a map requires you to look really closely at it and to understand what it is showing. You will want to examine the key carefully to understand the map fully.

The main features which help to describe a map are the direction sign and the scale line. With these you can say what is found where, and how far away, and in what direction other features are.

For example, you might say: 'This map shows a small village with the river flowing in a meander westward through it. There are two bridges over the river and the village. The A46 road runs through the village in a north south direction and, 50 metres to the west of the road, is a church located on the banks of the river. There are two schools in the village. One is at the southwestern edge of the village while the other is at the northeast. There is a post office and shop on Main Street.'

Sometimes it is necessary to give a brief description of a map to put into words what it is showing and to which elements you want the reader to pay closest attention to.

There are other types of map that provide a representation of the landscape.

Sketch maps

Sketch maps are simple drawings of the landscape. They show things that are sometimes hidden in photographs or maps, eg the impact of tourists on a landscape.

Sketch maps may be shown as a bird's-eye view or as a drawing of the horizon. They can be drawn whilst on fieldwork or from a photograph. It is useful to annotate sketch maps or include a photograph alongside it.

Photographs

Photographs can be taken from different locations:

• Ground photographs – these can be taken during fieldwork, using a camera or mobile device. They need to be annotated to show any features.

• Aerial photographs – these are usually taken from an aeroplane or a drone. They cover a wider area than ground photographs so they are useful in showing spatial patterns.

• Satellite images – these are high-resolution photographs taken from satellites in space. They show a very wide area, but in less detail than close-up images.

GIS maps

Geographical information systems (GIS) maps are digital maps that have layers of data added to them. GIS maps can be changed to show specific information about a place. Information layers can be shown as:

• area shading - sections of the map are shaded to show patterns

• graphs - bar charts, pie charts and proportional symbols are overlain

• photographs - photographs can be added to points on the map

• flow lines - lines to show movements between places

Annotating maps and photographs

Annotations are detailed labels with an explanation of what is shown. They are important because they allow us to interpret and compare maps and photographs. Annotations can focus on physical and human features and they usually include key terms.