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Unformatted text preview: Making Maps With GIS
Making Maps With GIS
8.1 The Parts of a Map
8.2 Choosing a Map Type
8.3 Designing the Map Getting Started with GIS
Chapter 8 The cartographer’s paradox What is a map?
“A graphic depiction of all or part of a
geographic realm in which the real-world
realfeatures have been replaced by symbols in
their correct spatial location at a reduced
scale.” Complete accuracy & completeness
– Scientific rigor Effective communication
Easy to read and interpret (intuitive)
Hard to misread (fault tolerant)
Hard power line 1 Producer’s Responsibility Map function in GIS
Intermediate check of data
Use in the field
To be effective, must be correctly
designed and constructed The Parts of a Map: Map Elements The medium is the message
THE DISPLAY IS PART OF THE SYMBOLIZATION 2 Cartographic Elements
Reference Cartographic Elements (3) Page coordinates
North Cartographic Elements (2)
Border and “collar”
– Scale up
– Scale down
Metadata e.g. index
Off- Cartographic Elements (4)
Title 3 Cartographic Elements (5)
Reliability Text: Selection and Placement Map “impact”
Distribution of Employment by State 2010
USA: Employment Distribution 2010
U.S. Employment: 2010 Distribution
America at Work
Where the Jobs are Today
America’s Great Recession
America’ Choosing Elements
Tools in GIS not ideal
Tools 4 Choosing a Map Type
Cartographers have designed hundreds of
map types: methods of cartographic
Not all GISs allow all types.
Most have a set of basic types
Depends heavily on the dimension of the
data to be shown in the map figure. Map Types: Point Data Choosing the Wrong Type
Fairly common GIS error
Due to lack of knowledge about
Can still have perfect symbolization
Possibility of misinformation
Definite reduction in communication
effectiveness Reference Map Reference
Graduated 5 Topographic Map Picture Symbol Map Dot Map Graduated Symbol Map 6 Map Types: Line Data Origin of Flow Maps
Harness, H. D. (1837). Atlas to
Accompany the Second Report of the
Railway Commissioners, Ireland.
Dublin: Irish Railway Commission.
Minard, C. 1869. Napoleon’s retreat
from Moscow Network
Reference Flow Maps Symbolizing flows 7 Flow Map: Truck traffic Map Types: Area Data
Reference Choropleth Continuous/Unclassed Choropleth 8 Area Qualitative Map Stepped Statistical Surface Hypsometric map Dasymetric 9 Cartograms Map Types: Volume Data
[Isopleth, Stepped Surface, Hypsometric]
Image Isoline Map Fishnet or Gridded Perspective View 10 Realistic Perspective View Hill-shaded Relief Map Image Map Map Types: Time
– Moving map
– Fly thru
– Fly by 11 Cartographic Animations Spatialization: SOM http://www.ncgia.ucsb.edu/projects/gig/v2/About/abImages/apps/sb_growth.gif http://www.aaronkoblin.com/work/faa/us.html Skupin, A. (2002) A Cartographic Approach to Visualizing Conference Abstracts. IEEE Computer Graphics and Applications. 22 (1): 50 - 58. Wordle Map Type and Dimensionality 12 Choosing Types
Check the data
– Accuracy & Precision
Dimension (Point, Line, Area, Volume)
Scale of Measurement (Nominal etc.)
May need to supplement GIS software
May Example: Choropleth Mapping
Data should be AREA (e.g. States)
Data should not suffer from area effect.
Per capita Income?
Areas non- Data Scaling (Stevens)
Nominal (Name of a place)
Ordinal (Small, med., large town)
Interval (Arbitrary zero e.g. Sea Level)
Ratio (Absolute zero e.g. dollars, densities)
Equal or unequal?
Logarithmic? Linear? Discontinuous?
How many classes?
Non-overlapping, distinctive groups.
Non- 13 The Need for Design
To appear professional and avoid errors,
GIS maps should reflect cartographic
knowledge about map design.
A map has a visual grammar or structure
that must be understood and used if the best
map design is desired.
Cartographic convention (e.g. forests should
be green). Symbolization Errors with a GIS Map Design
A GIS map is designed in a process called
the design loop.
Good map design requires that map
elements be placed in a balanced
arrangement within the neat line. 14 The Design Loop Graphic Editors Create map layout as macro
Draw on screen (proof plot)
Repeat until happy
Make final plot
Make Graphic Editor Software Third Party Design Software Vector
– Adobe Illustrator
GIMP 2.0 15 Map Design (2) Visual center Visual balance is affected by:
the "weight" of the symbols
the visual hierarchy of the symbols and
the location of the elements with respect to
each other and the visual center of the map. Visual Layout Alignment Title Here Title Here Eye expects (1) balance and (2) alignment 16 Symbol “weight”
Line weight Pattern Shading Color and Map Design
Color is a complex visual variable and in a GIS is
specified by RGB or HSI (CMYK 4-color) values
4Red, Green, Blue are additive primaries
Magenta, Cyan and Yellow are subtractive
May support transparency layer
Saturation and Intensity map better onto values
Figure/ground relationship critical
Figure/ground Hue Color printing composites GE Transparency/Opacity Cyan Magenta C
K Yellow 17 Dimensions of Color Simultaneous Contrast
HUE INTENSITY SATURATION Simultaneous Contrast Illusion Color Primaries Subtractive color Additive color 18 Design Assistance: ColorBrewer Text placement
Path right Santa Barbara
Santa Barbara Lagoon Scale and Generalization P
n Multivariate data Smaller scale means fewer features.
Smaller scale means smoother features.
Smaller scale means combining features.
Smaller scale means displacing features.
Often scales are mixed or over-generalized.
over- 19 Small multiples Geovisualization software Mixing Symbols Visual analytics:
the science of analytic reasoning, facilitated by interactive visual interfaces. http://vita.itn.liu.se/gav/gav/1.174303/GAV-Demo.png
http://www.perceptualedge.com/blog/wp- content/uploads/2009/01/horizon- graph- 20 Map Design and GIS
When a GIS map is the result of a complex
analytical or modeling process, good design
is essential for understanding.
The map is what distinguishes GIS as a
different approach to the management of
information, so extra care should be taken
to improve the final maps that a GIS
generates in a GIS task. Coming next… How to pick a GIS
How 21 ...
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This note was uploaded on 12/28/2011 for the course GEOG 176a taught by Professor Clarke during the Fall '09 term at UCSB.
- Fall '09