GIS Brownbag Series Making Maps that Communicate.

GIS Brownbag SeriesMaking Maps that Communicate

Making Maps that CommunicateMaking Maps that Communicate

Most important question: communicate what?

• Share information

• Highlight patterns and processes

• Illustrate results

• Planning

• Create an interesting and visually pleasing picture

Primary goal:Primary goal:

Secondary goal:Secondary goal:

Warning:

“map creator is very much the arbiter and architect of what the map portrays”

Drawbacks of maps: Maps can lie


Key points:

• Maps convey information

• Maps must be easy to use – easy to interpret

• Maps must be transportable

• Large number of people must be able to use those maps

In this context, what are the advantages of a GIS over traditional paper maps?


A good map is a map that communicates wellA good map is a map that communicates well

A good map…

.. Looks good

.. Is simple and elegant

.. Is fit for intended purpose

Which of those three is the most important?

What you map will look like is determined by..What you map will look like is determined by..

1. Purpose

2. Reality (e.g. shape of a country may determine the layout of the map)

3. Available data (Is the data in raster format? Are your rivers polygons or lines?)

4. Map scale (Determines how much area is covered on a map)

5. Audience (How much knowledge do they have? Do they want summaries?)

6. Conditions where the map is used (light levels of areas where map is being used)

7. Technical limits (paper map? Paper size? Internet browser constraints?)

Map elementsMap elements

• Main focus

• If comparing maps, there could be two map bodies

• Area of interest in more detail or

• Location of Map Body in smaller scale map



Map elements: scalesMap elements: scales

Scale bar:

Scale text:

Map elements: North ArrowsMap elements: North Arrows

Map elements: MetadataMap elements: Metadata


Key point for making a Key point for making a good mapgood map:

• Purpose of the map

• Show a location? Directions? Trend?

• Every map should have only 1 purpose

• Who will read your map?

Why is this important to consider?

• Target the person least prepared to understand you map’s message

• Include enough information so that this hypothetical person can understand the map

• Is anybody in the audience color blind?

About 1 out of every 20 people is colorblind.

Key points for making a good map: Key points for making a good map: AudienceAudience

• Purpose

• Audience

• Purpose

• Audience

• Size and scaleHandheld mapsHandheld maps

Handheld maps (roadmaps)• Smallest font is six points six points

• Can support complex and detailed symbology

• Keep content simple

• Use simple symbols

• Purpose

• Audience

• Size and scaleTiny MapsTiny Maps

• Keep it simple

• Simple symbology

Why, given this is a large-scale map?

Viewed from large distances

Large MapsLarge Maps

Sources: World Wildlife Fund, Wildlife Conservation SocietyAsian Bureau for Conservation, World Conservation Monitoring, and ESRI.

±

500 0 500 1,000Kilometers

Projection: Lambert Azimuthal Equal Area

500 0 500 1,000Kilometers

Projection: Lambert Azimuthal Equal Area

Existing reserves

Wildlife reserves

India

Other countries

Proposed reserves

High priority

Medium priority

Low priority

To be surveyed

India

Other countries

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• You want to direct your audience to your message

Message: Ada county has the largest

population in Idaho


Focus

• Where does the map reader look first?

• Position ….

•Experiment: write down the first number that you see...

17 41 33

1162 21

19 27 14

12 31 22

17 41 33

1162 21

19 27 14

12 31 22

17 41 17

1162 21

19 27 14

12 31 22

How could you make this map better?

Better map:

Use colors to get your message acrossUse colors to get your message across

How to make a visually pleasing map…How to make a visually pleasing map…

Balance: placement of the title

How to make a visually pleasing map…How to make a visually pleasing map…

Tip: Place the title slightly closer to the elements on the map than the top of the page

• Too much white space

• Object of interest is so small that it is hard to read

• Scale is in awkward numbers

• Legend has too much unimportant information

Black and White MapsBlack and White Maps

What do you think of the legend?

• Some classes have identical coloring

• Not intuitive: color for medium burn is most intense…

Round numbers for the scale

Very good use of patterns

Symbology: ConventionsSymbology: Conventions

Part of a 7.5-minute topo-graphic map at 1:24,000 scale produced by the USGS

Rules about:

•Colors (e.g. water is blue)

•How certain features are abstracted

•Symbols that are universally recognized

Sticking with Conventions at IDWR

You can find layer (.lyr) files on the X: drive that contain symbolization

ArcGIS let’s you choose from many symbols

Pick a symbol that makes sense

Symbols should be intuitive

What can you tell about this map even without the legend?

Symbolizing points: Symbolizing points: QuantitiesQuantities

Earthquakes

Symbolizing points: CategoriesSymbolizing points: Categories

Use different symbols to symbolize categories

Tips for selecting colorsTips for selecting colors

• Most People can only distinguish 7 classes

• For 4-5 classes uses shades of the same color

• People interpret darker colors as “more” or “greater”

• It is easier to distinguish shades of blue or purple

• Use common sense: bright green may be lush vegetation, brown is desert, bright red is hazard

Next Brown Bag Lunch:

CCleaner –presented by Glen Gardiner

Wednesday July 15

Interested in a specific topic for future lecture?

Contact Wilma

287-4830

GIS Brownbag Series Making Maps that Communicate.

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