Different types of mapping techniques
Some data is easier to understand when it is shown on a map. This is especially true of spatialRelating to space or how things are spread out. data, where the spread of the information is important.
Choropleth maps
Choropleth maps show interval dataNumbers that are in order and that have fixed differences between the values. (data that is linked, rather than data from different categories) as colours. They are shaded in using one colour, where the darker shades represent high numbers and the lighter shades represent low numbers. A choropleth map needs a key to explain what the different shades mean. population densityThe average number of people in a certain area. can be shown using a choropleth map.
Isoline maps
Isoline maps show lines that join up areas or values that are equal. atmospheric pressureThe weight of air resting on the Earth's surface. is shown using an isoline map. The areas of equal pressure are joined using a line, which helps people to see the position of high and low pressure systems.
Dot maps
Dot maps show information as individual dots on a map. Each dot might represent more than one of something. Dot maps are often used to show population distributionThe location of people in an area..
Desire lines and flow lines
Desire and flow line maps show movements from one place to another:
- flow lines show the exact path of movement
- desire lines show a general direction of movement
Movements are shown as lines. Thick lines show high amounts of movement and thin lines show low amounts. tradeThe exchange of goods for money between producers and consumers. or migrationWhen people move from one place to another. patterns are often shown using desire or flow lines.
Proportional symbols
Proportional symbols can be added to a map to show differences between places. The same symbol appears larger or smaller, depending on how something changes. Proportional symbols on maps could be used to show the number of wind farmLand which contains a large group of wind turbines. within a country.