Making Maps With GISMaking Maps With GIS

Wh t i ?What is a map?

• “A graphic depiction of all or part of a geographic realm in which the real-world features have been replaced by symbolsfeatures have been replaced by symbols in their correct spatial location at a reduced scale.”

power linepower line

Maps

Map:

• A graphical presentation of geographic information It• A graphical presentation of geographic information. Itcontains geographic data and other elements such asa title, north arrow, legend, and scale bar.

• You can interactively display and query thegeographic data on the map and also prepare aprintable map by arranging the map elements aroundthe data in a visually pleasing manner.

Making Maps: Maps:

A representation of the spatial organization of theA representation of the spatial organization of thephysical universe at any scale. A map also containsa wide variety of information both static anda wide variety of information, both static anddynamic. Maps are usually created on a flat, two-dimensional surfacedimensional surface.

Cartography:The art and science of map production CartographyThe art and science of map production. Cartographyis comprised of the fundamental scientificprocedures of accurate measurement classificationprocedures of accurate measurement, classification,and the identification of relationships, to createvisual models of our complex worldvisual models of our complex world.

M d C t hMaps and Cartography

• Map – ‘digital or analog output from a GIS showing information using well established cartographic conventions’cartographic conventions

• Cartography is the art, science and g p y ,techniques of making maps

M f ti i GISMap function in GIS

• Storage• Temporary communication• Intermediate check of data• Final report• Final report

Ch t i ti f MCharacteristics of Map

• Two main types– Topographic– ThematicThematic

• Some map problems– Can miscommunicate– Each map is just one of all possible mapsEach map is just one of all possible maps– Complex maps can be difficult to understand

Topographic Map

Thematic Map

M TMap Types

• Point data• Line data• Area data• Volume data• Volume data• Time data

Ch i M TChoosing a Map Type

• Cartographers have designed hundreds of map types: methods of cartographic representationrepresentation.

• Not all GISs allow all types.yp• Most have a set of basic types• Depends heavily on the dimension of the

data to be shown in the map figuredata to be shown in the map figure.

Ch i th W TChoosing the Wrong Type

• Fairly common GIS error.• Due to lack of knowledge about

t hi ticartographic options.• Can still have perfect symbolizationCan still have perfect symbolization.• Possibility of misinformation• Definite reduction in communication

effectivenesseffectiveness.

Ch i TChoosing Types

• Check the dataC ti– Continuous

– Discrete&– Accuracy & Precision

– Reliability• Dimension (Point, Line, Area, Volume)• Scale of Measurement (Nominal, ordinal, etc.)• GIS capability• Is there a need to supplement GIS software? (e.g. with a pp ( g

drawing package)

Th N d f D iTh N d f D iThe Need for DesignThe Need for Design

To appear professional and avoid errors, To appear professional and avoid errors, pp p ,pp p ,GIS maps should reflect cartographic GIS maps should reflect cartographic k l d b t d ik l d b t d iknowledge about map design.knowledge about map design.

A map has a visual grammar or structureA map has a visual grammar or structureA map has a visual grammar or structure A map has a visual grammar or structure that must be understood and used if the best that must be understood and used if the best

d i i d i dd i i d i dmap design is desired.map design is desired. Cartographic conventionCartographic conventions should bes should be Cartographic conventionCartographic conventions should be s should be

followedfollowed (e.g. forests should be green).(e.g. forests should be green).

M D iMap Design

• Good map design requires that map elements be placed in a balanced arrangement within the neat linearrangement within the neat line.

• A GIS map is designed in a process called p g pthe design loop.

To be effective, a map must be correctly designed and constructed.

The Parts of a Map: Map ElementsThe Parts of a Map: Map ElementsNeat line Border Title

The United States of America

Figure

Legend

AlaskaWashington,D.C.National Capital

ScaleGroundAlaska

Lambert Conformal Conic ProjectionSource: U.S. Dept. of State

0 41 2 3hundreds ofkilometers

0 4 0 4

Hawaii

Sou ce: U.S. ep . o S e0 4 4

CreditsNorth ArrowPlace nameInset CreditsNorth ArrowPlace nameInset

Inset map

Author

Scale

North Arrow

Data SourceMap Body

TitleLegend

Projection

Grid

Vi l b l i k !Visual balance is key!

• Visual balance is affected by:the "weight" of the symbolsthe visual hierarchy of the symbols and

elementselementsthe location of the elements with respect

to each other and the visual center of the mapmap.

Vi l tVisual center

5% of height

5% of height

Landscape Portrait

Vi l L tVisual Layout

Title Here

Title Here

Eye expects (1) balance and (2) alignmenty p ( ) ( ) g

M d d i bj tiMap and design objectives

Wh t th M• What are the Map objectives?– Share information– Share information– Highlight

relationshipsp– Illustrate analysis

results– Decision support

Wh t th D i• What are the Design objectives?

Manipulate the– Manipulate the graphic characteristics

– Fulfill the intended purpose

Identifying map elementsy g p

Title

What other map elements are missing?

Map bodymissing?

• Scale text (1:100,000)

• Other text (author name• Other text (author name, disclaimers, projection information, date of data, date

f d )

North arrowLegend

Scale bar Designed by Committee 2004

of map, and so on)

• LogosScale bar Designed by Committee 2004

Other textOther textWhat is missing?

Identifying map elementsAre all these map elements really necessary?S l t b i d if

TitleSome map elements can be ignored if other map elements or features can substitute for it. For example, a north arrow is redundant if you have neatlines shown with coordinate labels such as latitude and longitude; a north arrow and

Map bodyg ;

a scale bar are both redundant if you are depicting the population of the United States in a book on United StatesStates in a book on United States demographic statistics; a scale bar can be redundant if neatlines are shown with the proper coordinate system and units

North arrowLegend

Scale bar Designed by Committee 2004

the proper coordinate system and units.Avoid placing any information that does not comply with the map’s objectives.

‘ ’Scale bar

Other text

These are considered ‘visual noise’ and distract from effective map communication. Other textWhat is missing?

Map Layoutp y

M D i d GISMap Design and GIS

• When a GIS map is the result of a complex analytical or modeling process, good design is essential forgood design is essential for understanding.

• The map is what distinguishes GIS as a different approach to the management ofdifferent approach to the management of information, so extra care should be taken to improve the final maps that a GIS generates in a GIS taskgenerates in a GIS task.

Li it ti f P MLimitations of Paper Maps

• Fixed scale• Fixed extent• Static view• Flat and hence limited for 3D visualization• Flat and hence limited for 3D visualization• Only presents ‘complete’ world viewy p p• Map producer-centric

GIS outputGIS outputThe 4 Components of GIS:p

data input -> database management -> analysis -> output

Output can be considered as:

tabular results

softcopy -> display

hardcopy -> printedJanuary 2010: ESRI Canada mapbook

Procedural Output StepsProcedural Output Steps

D f d la. Determine purpose of output and scale

b. Which theme layers / items - foreground /background

c Design map elements: symbols / coloursc. Design map elements: symbols / colours

d. Design map layout – title, scale etc..

General design rules:

Associate symbols with features e.g. blue for water

Sequences are logical e.g. increasing widths for road sizes

Area polygons - Choice of boundary line or area fillArea polygons Choice of boundary line or area fill

Colours - avoid dark solids for areas and ensure sufficient contrast

General rules for feature layers

Points: abstract or iconic, outline or filled ?

LinesLinesWidth – depends on feature importance

General rules•Solid for ‘real’ on the ground•Solid for real on the ground

D h d f l •Dashed for less permanent

•Dot-dash for administrative

Don’t just go for defaults (e.g. streams are too wide)

Areas

•Visual contrast

•Simple patternsSimple patterns

•Avoid solid colours except for X•Avoid solid colours except for small areas

X ! ->•Colours should be associative

Avoid school tie stripes !

Lettering (by Vicki Drake)Lettering (by Vicki Drake)

Labelling layer features

(simple rules)(simple rules)

Points: Above (to the right)

Lines: above and aligned

Areas: aligned with shape (inside)

Italics for water features

Print formatsPrint formats

(You can’t directly print an arcmap mxd)

Common graphic output formatsPostscript (PS)

Encapsulated Postscript (EPS)Encapsulated ostscr pt (E S)

H l tt P k d G hi L (HPGL) Hewlett Packard Graphics Language (HPGL)

Adobe Acrobat Portable Document Format (PDF)

C l iConclusions

• Cartography is both an art and a science• Maps are fundamental to GIS projects• Modern advances in cartography make it• Modern advances in cartography make it

easy to produce good and bad maps• New technology and especially the

Internet has change the content andInternet has change the content and techniques of GIS-based cartography