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• Geographic Information Systems (GIS) is specialist software that links geographical data with a map.

• Geographic Information Systems (GIS) enables users to add layers to show different information and zoom in and out to different scales.

• GIS is a useful source of secondary data and it can be used to plan geographical enquiries.

Geographic Information Systems (GIS) is specialist software which links geographical data with a map. GIS is useful for geographers as it enables users to add layers to show different information as well as zoom in and out to different scales. GIS often links together digital maps, satellite images or aerial photographs, allowing the user to compare these different layers.

GIS is widely used. It can be used with a range of software, from satellite navigation systems (satnav) and online maps to more specialised software such as ArcGis and Digimaps. GIS maps can be very simple or very complicated depending on how GIS is used. It can be used for a range of different purposes, from producing a simple map to the processing and analysing of data.

GIS is useful when planning and conducting geographical enquiries. GIS can be used for selecting a location, planning a route or collecting secondary data. There are many sources of secondary data online in map form. For example, the Environment Agency provides flood risk maps and The Department for Levelling Up, Housing and Communities produces maps to show areas of poverty across the UK.

A choropleth map uses shades of the same colour to show the distribution of data. A choropleth map has a base map showing different regions or areas. This might be at a global scale or a local scale. The data studied is divided into categories with equal intervals and each category assigned a colour or shade. Usually, the darker the shade, the higher the value. A key is always included to ensure the map is easy to interpret.

Choropleth maps are a visual way to show differences between different areas and can be used at a variety of scales from global to local. They can be used to identify hotspots (areas where the factor being measured is significantly higher than elsewhere) and to identify any relationships between location and the factor being studied. In the map above, for example, population hotspots can be seen in cities such as London, Birmingham, Glasgow and Edinburgh.

Choropleth maps do, however, have limitations. For example, they may show the whole country as one colour where in reality there are significant variations within that country.

In China, for example, rural literacy rates are much lower than urban literacy rates. In Beijing, 98.27 per cent of people can read and write compared with Qinghai where the literacy rate is 89.4 per cent. On a choropleth map that showed data at a national scale without showing the differences between areas, the whole country would be shown as one uniform colour representing the average.