Lecture 2: Cartography and the power of the map Flashcards
What are maps useful for?
Recording and storing information
As a way of analysing spatial distributions and patterns
As a method of presenting and communicating findings which are difficult to express verbally
What are maps typically classified by?
Scale or function
What is the scale of a map?
the ratio of a distance on the map to the corresponding distance on the ground
What does a large scale map show?
Shows a small geographic area in great detail
What does a small scale map show?
shows a large geographic area in less detail
What do topographic maps show?
a range of features, both natural and human, in the landscape
What do thematic or ‘special purpose’ maps focus on?
the distribution of a single variable – or the relationship amongst several.
2 examples of common thematic maps?
choropleth maps and contour maps
What are choropleth maps used to communicate?
the relative magnitudes of continuous variables as they occur within the boundaries of unit areas.
What do we use choropleth maps to display?
Commonly used to depict census data, such as population density as it varies by county
What do dot maps depict and how?
depict spatial distributions by varying numbers of uniform dots.
What are line maps used for?
used to show the direction and magnitude of potential or actual flows.
What happens in cartographic maps?
Shape is distorted in order for size of the areas to be representative of something
What do we use heat maps to show?
Heat maps show the magnitude of something as a colour in two dimensions.
What do we need to do to create an effective topographic map?
We need to reduce the scale and eliminate unwanted detail.
We must then fit the selected features on the map in an effective manner that aids understanding.
Selection definition
Limit our concern to those classes of information that will serve the map’s purpose
Generalisation definition
Fit the selected features on the map at the desired scale in an effective manner that aids understanding
How can a map have clarity and be legible?
It should be clear what the map is trying to communicate
Clearly differentiate any features of the map (careful with colours/width)
How can a map have hierarchy and structure?
Some layers have a clear hierarchy within them, such as roads, where motorways are more important than minor roads; or settlements where cities are more important than villages.
You should aim to make the more important details stand out
How should a map use colour and patterns?
Use conventional colours when possible (e.g. blue for water)
How should a map use visual contrast?
Consider varying symbol size, shape, colour or texture
For lines you can vary width as well as colour, showing a hierarchy
What should be the relationship between contextual features and key information on a map?
Supporting contextual features should stand out less than key information your map is conveying
