2. Objectives
• Understand basic map design concepts and
principles
• Understand color use in maps
• Understand scale and how it affects what we can
map
• Understand use of symbols to convey meaning
3. Map Purpose & Audience
• Know what your story is
• Know who you are telling the story to
• Know how you are telling your story
-paper
-computer screen (Web)
-powerpoint, etc…
5. Map Media
Map media may be classified into two main types:
1.) Print (hard copy)
-publications, brochures, magazines
-black & white or Color?
2. Electronic media (soft copy)
-Web (cell phone, tablet, laptop, etc…)
13. Map Design-Use of Color
• Color perception has physical,
physiological, and psychological aspects
- Green , often used to denote “Good”
-Blue & purple, often used to denote “Neutral”
-Red, often used to denote “Bad”
-Lighter colors mean less of something
-Darker colors mean more of something
15. Map Design: Use of Color
Hue
Saturation
Intensity
Color differences show categories or gradations
16. Map Design: Color Ramps
The type of data being mapped should determine the
type of color ramp used
• Quantitative– a graduated or sequential color
scheme
• Qualitative – a random or qualitative color
scheme
17. Map Design-Use of Color
• Color blindness
– 5-8% of men
– 0.5% of women
19. Map Scale
• Map scale is the proportion between a distance
on a map and a corresponding distance on the
ground
20. Map Scale
• Large-scale maps cover small areas, but can
include a higher level of detail. Think “zoomed-in”
view.
-City maps
• Small-scale maps depict larger areas at lower
level of detail. Think “zoomed-out” view.
-World maps
22. Map Scale
• Where is the scale information for GIS datasets?
• How does scale effect our use of GIS datasets?
--GIS dataset do not state the scale on the map, because you
can change the scale by zooming in and out.
--The scale that was set to create GIS datasets can be found
in the metadata
--How far we can zoom in and out reliably on a dataset
--Which GIS datasets we can integrate together
23. Map Scale
• Map scale determines the size and shape of features
1:500
25. • Map scale is important because it affects the
level of detail a map and a GIS dataset can
shown
Key Points
• Data characteristics have an impact upon
symbol design
• Before making your map, think about
what, who, & how
• Knowing how color and map design
principles can increase your map’s
readability
This session introduces map layout and cartographic design practices and principles with a focus on use of color, readability of data, and interpretation of data.
This presentation will be followed by a fun activity to illustrate the impact that color and readability of data on maps.
If you would like, please take notes in your participant’s guide on page 75.
Understand basic map design principles-visual hierarchy, balance, and, generalization
Understand color use in maps
Understand scale and how it affects what we can map and the level of detail of what we can show (extent)
Understand the use of symbols to convey meaning
A map’s primary purpose is to communicate information to the map reader.
If asked to make two maps, and starting with the same datasets, a cartographer may produce very different looking maps, depending on who they are designing the map for and how the map is going to be used.
Before you even sit down to make the map, see if you can figure out the story you want to tell, the audience you want to tell it to, and the media you will tell it through, such as paper, a PowerPoint, image, the Web, etc. Thinking through these 3 things will save you a lot of time in the map making process.
The process of using a map is fairly intuitive. After all, maps are a form of visual data processing and the human visual system is the most complex and powerful information system known.
There’s a reason why people say a picture is worth a million words.
There are two broad categories of maps.
Reference maps are designed to show where geographic features are in relation to each other without a specific emphasis on one type over another.
Thematic maps are designed to convey information about a single topic or theme, such as population density or percent of women who gave birth at a health facility as shown here.
It’s important to know what kind of map you will be producing because it will affect your design choices and use of symbols.
Maps designed for print media are known as hard copy maps, while maps designed for viewing in an electronic form are referred to as soft copy maps. JPG is good for electronic media, while pdfs are generally good for printed media. The reason for this is that the resolution on computer screen is lower (72 dpi) than printers.
A map is a metaphor. It is just one version of reality, and the way that it depicts reality depends on the media.
Cartographers have developed design principles that make communication of your story more effective and efficient.
Balance involves the organization of the map and other elements on the page.
A well-balanced map page results in an impression of equilibrium and harmony.
Studies show that most humans scan a page starting at the upper left corner and then the eyes move slightly above the center of the page
Which of the top six maps seems most balanced?
It should appear that (F) has visual equilibrium, usually achieved by placing the central figure slightly above center on the page.
Positioning heavier elements together can make the page look top-heavy (A) or bottom heavy (B).
Centering the map slightly above center (C) ensures that it is in the most prominent position on the page. The position of elements can also cause the eye to move in a desired direction.
Yohanna talked a little bit about visual hierarchy in terms of labelling features earlier.
You can think of a hierarchy as the visual separation of your map into layers of information. Some types of features will be seen as more important than other kinds of features.
And some page elements, like the map body will seem more important than others elements, like the the title or legend.
This visual layering of information within the map and on the page helps readers focus on what is important and enables them to identify and interpret patterns.
Cartographers use visual cues, such as size, position, arrangement, and color contrast to create a sense of depth on a flat map and enable a quicker reading of the map for meaning and importance.
When you look at this figure, do some elements look like they are on top of the other elements?
I talked earlier about the two main kinds of maps: reference and thematic.
In reference maps, hierarchy is usually more subtle and the map reader brings elements to the forefront by focusing attention on them.
For thematic maps, the theme is more important than the base data that is there only to provide a geographic context so that main theme pops off the page more.
Elements that are placed near the top and towards the center of the page will appear higher in the visual hierarchy than those that are towards the bottom or are at the edges of the map.
Visual hierarchy in the layout helps direct map readers to the most important information first.
Do you think it’s really necessary to include a north arrow in this map? Why? Why not? Most map readers know which direction north is seeing how the shape of the Africa is oriented on the map. But if you are creating a map of downtown Dar es Salaam, you would want to put a north arrow to help orient the map reader.
This map show visual layering of information to help readers focus on what is important and enables them to identify patterns much more easily.
What about this map? Does it have good visual hierarchy? Why/why not?
Figure-ground organization is the separation of the figure in the foreground from the background. Cartographers use this design principle to help their map readers find the area of the map or page to focus on.
The higher the contrast between features, the more something will stand out, usually the feature that is darker or brighter.
Conversely, a map that has low visual contrast can be used to promote a more subtle impression. Features that have less contrast will appear to belong together.
When there is no variation in visual contrast, the map reader has a hard time distinguishing features from the background.
Objects that stand out in the visual field are called figures, while the rest of the display makes up the ground.
Our eyes will automatically separate parts of an image into figure and ground.
Color perception and how humans perceive color is an ancient and philosophical debate. Is how we see the world really how the world is or is everything we see due to our perception alone?
Before I get too philosophical here, there is some agreement in about what certain colors mean or convey in mapping.
Red often denotes “Bad”
Green often used to denote “Good”
Blue and Purple, often used to denote “Neutral”
Darker colors mean more of something
Lighter colors mean less of something
Here we see an example of appropriate color use in maps,. Blue is used to show a positive variable and darker means more of something, literacy rates.
The other map shows red to map a negative variable and dark red means more of something bad.
Different hues are used to show different types of things whereas saturation and intensity are used to show different quantities of things.
Can somebody give me an example of a thing that can be grouped into multiple categories?
Can somebody give me an example of something that can be measured on a scale?
The type of data being mapped should determine the type of color ramp used.
Data that is different in terms of kind is best mapped with different colors.
Data that is different in terms of quantity is best mapped with a graduated color scheme where the same color is used with a different amount of saturation to show a scale.
An important consideration to think about is color-blindness.
About 5-8% of men have some type of color blindness, with 0.5% of women. Even though it’s a small percentage of the overall population, poorly chosen colors can mean that the map is unreadable for them. There are color-blindness safe color schemes that are available.
There is no standard cartographic sign-system that map readers have agreed upon.
Cartographers can match any symbol to any type of map feature.
However, creating map symbols without carefully thinking through how they might be interpreted is likely to result in map readers drawing incorrect conclusions about what they see in the map.
For this reason, cartographers have come up with a series of guidelines about how to match the different visual characteristics that we can use for creating symbols to the characteristics of a data set.
The visual variables that work best for showing qualitative differences or differences in kind or type are: color hue, shape, and orientation.
The visual variables that do a good job of showing differences in amount or quantitative differences are: color saturation, size and texture.
As participants for examples of each kind of data.
I’m sure you have heard the term large and small scale before. What do they mean to you? Often, social scientists use the term large scale project to describe a project that is comprehensive or covers a large area.
In GIS, the term scale is used quite differently. When we talk about large and small scale maps, we are talking about the relative sizes of and levels of detail of the feature represented in the data.
Scale is important for you to understand because it affects the level of detail a map and GIS data set can show.
Map scale can be communicated three different ways on a map: graphically, as a representative fraction, or stated textually.
If using scale bars to communicate map scale, they should use well-rounded numbers, e.g. 1, 5, 10, 1000, etc, that can easily be used by the map reader.
For many thematic maps where distance is not of main concern, a very basic scale bar should be used.
Map size and scale influence the number of features and the level of detail that a map can show. Together, the size and scale determine how much information can effectively be communicated with a map. Too much information will confuse and overwhelm. A map that provides too little information, however, won't get its message across.
Generalization is a key concept in GIS that not by coincidence relates to scale.
Generalization is the reduction and simplification of features for change of scale or resolution.
The idea is that if you’re zoomed way out, the features on your map are going to look less detailed and intricate compared to when you’re zoomed in.
Before you sit down to make your map, think about 3 things: what’s the story you want to tell, who is the audience you want to tell it to, and how are you going to tell it (what media will you use).
Smart use of color and map design principles, like visual hierarchy, balance, figure ground, can make your map easier to interpret and understand.
Maps come to life when color and different symbols are used to help you to tell one type of feature from the next.
Map scale is important because it affects the level of detail a map and a GIS dataset can shown.
And lastly, the kind of data you are mapping impacts the kind of symbols you should chose. We talked about data that is different in type (qualitative) versus data that is different in amount, or quantitative.
