Data Display and Cartography

Chapter 8 – Chang

Week 5

Map Elements

• Title• Body – most important• Legend• North Arrow• Scale• Acknowledgement• Neatline/Map border• Others (options): Projection, grids, insert, data

quality information.

Exercise

• Add the following elements to your county map– Title– Legend– Scale Bar– Acknowledgement– North Arrow– Neatline/Border

Map Symbols• Points• Lines• Polygons• Exercise – • Open your ArcMap/ArcView project with your county census tract polygons. • Add GPS points to the map.• Download Street file from TIGER website (

http://arcdata.esri.com/data/tiger2000/tiger_download.cfm) – select TN– Select County name, then click Submit Selection– Select Line Features – Road and click Proceed to Download.– Click Download File– You should get a zipped file starting with lkA47xxx.zip. Start unzipping this file to

get your road layer (again, it contains three files for a shape)– Move these three files to your folder (you’d better have a folder named “Data”

under your personal folder)• Add this road layer to your county map

Size, Color and Patterns

• Adjust size of point symbols (grouped, not individually for the event points data)

• D-C on tgr47141trt00 (in ArcMap) to bring up the “Layer Properties” window.

• Select Unique Values under Categories and click “Add All Values” button from the window. You will have to choose a Value Field, such as tgr47000demtrt.P0010001.

• This will you the choices of individual colors for each polygons.

Color

• Hue – colors – wavelength• Value – lightness/darkness of a color, black to

white. Usually, darker colors are more important features.

• Chroma (saturation) – richness/brilliance of a color. A fully saturated color is pure, whereas a low saturation approaches gray.

• Rules : Hue is for qualitative data. Chroma and Value are for quantitative data.

• Quantitative mapping received much more attention than qualitative mapping

Color Schemes• Single Hue Scheme – varies value and chroma to

show sequential order• Hue and Value – from light value of one hue to a darker

value of a different hue. Examples are yellow to dark blue (or dark red). Better for recognition of general map information

• Diverging or double-ended scheme: use graduated colors betw two dominant colors, eg from dark blue-> light blue->light red -> dark red. Good for negative - > positive values, and other maps too.

• Part Spectral Scheme – use adjacent colors of the visible spectrum to show variations in magnitude, such as from Yellow to Orange to Red, Y – G – B.

• Full Spectral Scheme – use all colors in the visible spectrum. Used in elevation, not recommended for other maps (no logical sequences)

Types of Maps – Thematic Maps

• Dot Map (your GPS points)• Choropleth Map (population in each tract)• Graduated Symbols (based on field

values)• Pie Chart map• Flow Map• Isarithmic map (contour)• Dasymetric map

Typography

• Serif (with serif), Sans Serif (without serif)- serifs are small, finishing touches at the ends of line strokes, which tend to make it easier to read running text in newspapers and books.

• Sans Serif : good for maps with complex map symbols and remain legible even in small sizes

• Type weight (bold/regular/light), Type width, font, size (in points),

Labeling

• Examples: use USA + City

• Identify maps with 1) confusing legend 2) too many boxes or other typographic errors in Internet.