School of GeographyFACULTY OF ENVIRONMENT
Introduction to Cartography
What is Cartography?
• Art/science/technology of making maps
• Beauty vs. usefulness
• Cartographic design is a complex task
• Unlimited options (16 million colours, many kinds of lines and symbols)
• A good map makes it easy for a reader to acquire your intended information by:
• Depicting data effectively
• Reflecting the relative importance of features
• Reducing distraction
Cartographic Objectives
• Map Objectives (Why?)
• Highlight spatial relationships
• Illustrate analysis results
• Convey information
• Easier comprehension of complex events
• Design Objectives (How?)
• Fulfill communication objectives
• Assign meaningful symbology
• Fulfill map objectives
• Ensure truthful depiction of reality
Issues of Detail + Symbology
• How much detail should I include?
• Depends on generalisation and scale
• E.g. Small scale – not interested in detail
• What symbols should I use?
• Qualitative: Can vary colour, shape, texture, pattern
• Patterns: repetitive type of symbol used for areas (e.g. swamps)
• Consider effects of reduction, e.g. paper + photocopier
• Quantitative
• Shading / intensity
• Size of symbols
Colours/Special Effects
• How many should I use?
• A maximum of 12 different colours
• A maximum of 7 to 8 shades
• Employ patterns/textures/text if you need more categories
• Consider how the map will be disseminated
• Colour on screen (16.7 million) different from printer (256 colours)
• Avoid special effects:
• squares of black and white/lines – 50% - vibration effect
• same shading on two different backgrounds
• use of lines (diagonal, vertical) as they imply directionality
Limitations of the Eye
Examples of Special Effects
• Avoid use of these in your maps:
Legibility of Symbols + Text
• Size of symbols?
• Have to know what your map is being used for
• At which distance will the map be viewed? E.g. a wall map? Reading distance? At a smaller distance, the symbols can be smaller
• Text issues?
• Text colour vs background colour (to get a good contrast)
• Uppercase vs lowercase (use a combination )
• No fancy fonts / avoid mixing font types
• Perfect vision?
• Not everyone has this – not too crowded, enough contrast between background and symbols, background + text
Cartographic Specifications
• Perception threshold = legibility of smallest detail
• Line thickness should not be less than .1 mm
• Points: 0.5 mm for points
• Separation threshold = distinction between adjacent features
• > 0.2mm e.g. road and rail road line
• Differentiation threshold = smallest difference between the nearest same size symbols, e.g. proportional symbols – can do this by artificially making symbols larger to increase the contrast
Visual Balance + Hierarchy
• Center of the map
• Visual weight
• Size, colour (value + intensity), how close things are to the edge (e.g. things on right have more visual weight)
• E.g. if put a large north arrow on the map, map is not good because the eye goes there first
• Gaps: should be avoided in the bottom but ok at the top (i.e. above the visual centre
• Do not want other elements to compete with the main map
• Make easy to use scale bars
Which is Most Balanced?
What About This One?
And One Final One….
Map Elements
• Title (avoid ‘Map of…’)
• Author and date of the data
• Map body
• Legend
• Scale bar / representative fraction
• Date of the map
• North arrow
• Projection
• Sources of the data, licensing
• Water Mark
Layout View in ArcMap
• Map content is contained in a data frame
• Layers, symbols and feature-based text (labels)
• Map elements
• Legends, scale bars, north arrows, graticules, et.
• Text, pictures, graphics added to the page
• ArcMap Data View vs Layout view
• Data view: used for exploring, displaying, querying and analysing spatial data
• Layout view: shows the virtual page upon which the map content and map elements are placed
Starting a Composition in Layout View
Page Layout Toolbar
• Draw layout items in Draft Mode
• Faster page navigation
• Can turn on all items or just an individual element
• Pause drawing button
• Use if you change feature symbols, label property, layer draw order, etc.
Refresh
Pause
Layout View
Data View
Active Data Frame
• Can only have one data frame active at once
• Active when bold in the table of contents + marquee around it in layout view
• To make a frame active: right-click Activate OR click + Alt key OR click on the window in Layout View
Layout View in Draft Mode
• Can move elements around without the map redrawing
Page Layout Aids
• Rulers, guides and grids
• Snap graphic elements to layout aids
• Settings layout aids
• Tools Options Layout view tab
Adding Map Elements
• Scale bar - adjust division values or adjust width
• Use Legend Wizard
• Graphics, Pictures: Use graphics toolbar
• Can convert any element to a graphic
• Grids and Graticules (reference systems)
• Use where north is not constant across the map or map is not to scale
• Graticule (geographic)
• Measured grid (projected)
• Reference grid (index grid)
• Are a property of your data frame – Grids tab
Adding a Water Mark
• Always add a water mark
• Needed for maps at a scale of 1:10,000 or greater but best practice is use all the time
• Load these into ArcMap
• 2X and 5X watermark files
• Use the Georeferencing toolbar: View Toolbars
• Put the watermark file into the drop down list
• Fit to display
• Ask your GIS team for more details
Map Templates
• Create maps from .mxt files
• Can use predefined ArcMap templates
• Create custom templates
• Use the LCC template
• Looking at this tomorrow!
Extent Rectangles
• Add an extent rectangle to an existing data frame
• Shows position of one data frame relative to another
• Extent rectangles are dynamic (will automatically update if changes if you zoom in on big map – extent rectangle changes)
• View Data Frame
Properties
Extent Rectangles tab
Mapping Resources
• Technology trends in GIS – Cartography
http://www.esri.com/technology_trends/cartography
• GIS for Map, Chart and Data Production
http://www.esri.com/industries/map-chart-dataproduction/
• ESRI Mapping Center
http://mappingcenter.esri.com/
Using Layout View in ArcMap
Hands-on Exercise #4