Geography 70  Map Design  Cartographic Communication

Uses of Maps  To record and store information for reference.  To analyze locational distributions and spatial patterns.  To present information and communicate findings (often to help facilitate decision-making).

Cartographic Communication  Success or failure on the part of the cartographer depends on whether or not the map communicates the intended information.

Cartographic Communication  How do I say what to whom? Cartographer (I) Cartographer (I) map reader/audience (whom) map reader/audience (whom) map design and production (how) map design and production (how) subject of the map (what) subject of the map (what)

Thematic vs. Reference  Thematic maps spatial distribution of particular variables spatial distribution of particular variables Often created by GIS analysts Often created by GIS analysts  Reference maps USGS Topo maps, navigation charts, tax maps USGS Topo maps, navigation charts, tax maps Generally created by large mapping organizations Generally created by large mapping organizations

“Rules” of cartography  Example: “maps should always have a scale bar”  ”Rules” should be considered in terms of what the cartographer is trying to communicate with the map  Example: A series of page-sized maps of the entire U.S. displaying different population variables by state? » a scale bar may not be important for these maps. Readers are likely to already be familiar with the size and shape of the U.S. Readers are likely to already be familiar with the size and shape of the U.S. The purpose of these maps has nothing to do with measuring distances. The purpose of these maps has nothing to do with measuring distances.  But, some guidelines...

Map elements  Most common: map/spatial data map/spatial data title title scale scale legend legend north arrow north arrow inset(s) inset(s) textual information (incl. spatial metadata) textual information (incl. spatial metadata) border, neatlines border, neatlines coordinate grid coordinate grid

 Largest and most noticeable text on the map  Be precise! no superfluous words.  Can be a label, or can be a sentence.  Consistent format in titles for maps in a series  No "Map of..." in the title -- we know it's a map Titles

Scale  Only graphic scales will survive enlargement or reduction during reproduction  Some thematic maps may not need a scale bar 10 miles

Legends  Almost always required on thematic maps  Symbolization in the legend must exactly match symbolization used on the map  No "Legend" in the title for the legend

Legend Map credits: MEASURE Project, Carolina Population Center, UNC-Chapel Hill

Legends

Insets  locator maps (where is this map in relation to the others?) Example: the Alabama page in a US road atlas Example: the Alabama page in a US road atlas  detail maps Example: Raleigh inset/blowup map on a North Carolina map Example: Raleigh inset/blowup map on a North Carolina map

Textual information  Common uses: author/publisher author/publisher date of production date of production date of map information date of map information projection type and coordinate system information projection type and coordinate system information data sources data sources brief information on how the map was produced brief information on how the map was produced

Borders, neatlines  Provide a graphic "container”

Map Elements Legend Scale Text: Projection/source North Arrow Inset Map/figure Neat line Border Title

Coordinate grid

Data symbolization  For vector data: basic symbol elements (Geographic Primitives) are: Points Points Lines Lines Areas Areas  Choice of symbol is scale dependent

Symbolization  Nominal/categorical data

Symbolization  Ordinal data

Symbolization  Interval Data

Symbolization  Ratio Data

Bertin’s Visual Variables  Jacques Bertin, French geographer classified different graphic methods for symbolization classified different graphic methods for symbolization called “visual” or “graphic” variables called “visual” or “graphic” variables

Bertin’s Visual Variables  NOTE: the list presented here adds Arrangement to the visual variables discussed in the Heywood text (p. 159, based on Bernhardsen’s work). Also, Density is mentioned by Heywood as separate from Texture, but is generally considered a component of Texture by Bertin.

Size  Difference in geometric dimensions (e.g. length, height, diameter) of symbols  Convention: larger size = greater quantity or importance OrdinalRatioNominal Good Good Bad  Utility

Shape  Differences in forms of symbols  Options: abstract (e.g circle, square) abstract (e.g circle, square) iconographic (e.g. airplane, flag, schoolhouse) iconographic (e.g. airplane, flag, schoolhouse)  Caution: too many different shapes can get very busy and difficult for the map reader to discriminate OrdinalRatioNominal Bad  Good Good Utility

Dimensions of Color HUE SATURATION INTENSITY SIDEBAR

Color Hue (Color)  Real color differences (not simply differences in intensity or saturation)  Perceptual difficulties for some map readers is a problem (e.g. 6-8% males color-blind) OrdinalRatioNominal Okay  Good Good Utility

Color Value  Intensity or saturation (relative lightness or darkness of symbols)  Convention: darkness = higher numerical values  Difficult for map readers to keep track of more than four or five values OrdinalRatioNominal Good Good Bad  Utility

Texture  Size and spacing of elements that make up a single symbol  Dense vs. sparse  Danger of aesthetically unpleasing appearance OrdinalRatioNominal Good Good Utility

Orientation  Direction of symbols  Useful for some nominal variables (e.g. wind direction) OrdinalRatioNominal rarely  Bad  Good Good Utility

Arrangement  Configuration (random vs. systematic)  Convention: random often used to symbolize natural phenomena (e.g. marshland)  systematic used to symbolize human-made phenomena (e.g. croplands) OrdinalRatioNominal Bad  Good Good Utility

Map Layout and Design  Key components to consider when designing a map 1. Legibility 2. Visual Contrast 3. Visual Balance 4. Figure-Ground Relationship 5. Hierarchical Organization

 Legibility Make sure that graphic symbols are easy to read and understand Make sure that graphic symbols are easy to read and understand Size, color, pattern must be easily distinguishable Size, color, pattern must be easily distinguishable Map Layout and Design

 Visual Contrast Uniformity produces monotony Uniformity produces monotony Strive for contrast/variation (but don’t overdo it) Strive for contrast/variation (but don’t overdo it) Variation can be expressed with Variation can be expressed with sizesize intensityintensity shapeshape colorcolor Map Layout and Design

Simultaneous Color Contrast

Map Layout and Design  Visual Balance Keep things in balance Keep things in balance Think about the graphic weight, visual weight Think about the graphic weight, visual weight Graphic weight is affected by darkness/lightness, intensity and density of map elements Graphic weight is affected by darkness/lightness, intensity and density of map elements Visual center is slightly above the actual center (Standard is 5%) Visual center is slightly above the actual center (Standard is 5%)

Visual Balance

Visual center 5% of height Landscape Portrait

Map Layout and Design  Figure-Ground Relationship Complex, automatic reaction of eye and brain to a graphic display. Complex, automatic reaction of eye and brain to a graphic display. Figure: stands out Ground: recedes Figure: stands out Ground: recedes

Map Layout and Design  Figure-Ground Relationship All other things being equal, there are factors that are likely to cause an object to be perceived as figure (i.e. stand out from background) All other things being equal, there are factors that are likely to cause an object to be perceived as figure (i.e. stand out from background) articulation & detailarticulation & detail objects that are complete (e.g. land areas contained within a map border)objects that are complete (e.g. land areas contained within a map border) smaller areas (relative to large background areas)smaller areas (relative to large background areas) darker areasdarker areas

Map Layout and Design  Figure-Ground Relationship Very difficult to develop a hard and fast rule with figure ground, relies on a mix of factors Very difficult to develop a hard and fast rule with figure ground, relies on a mix of factors

Map Layout and Design  Hierarchical Organization Use of graphical organization schemes to focus reader’s attention Use of graphical organization schemes to focus reader’s attention

Hierarchical Organization  Extensional “Ranks Features on the Map” “Ranks Features on the Map” Use of different sized line symbols for roadsUse of different sized line symbols for roads

Hierarchical Organization  Subdivisional Portrays the internal divisions of a hierarchy Portrays the internal divisions of a hierarchy Example: Regions of North Carolina Example: Regions of North Carolina

Hierarchical Organization  Stereogrammatic Gives the impression that classes of features lie at different levels on the map Gives the impression that classes of features lie at different levels on the map Those on top are most important Those on top are most important

Western Mounis Piedmont Coastal Plain

Text: Selection and Placement POINT LINE AREA (Good) (Good)