Outline. Map Production: Cartography. Topographic Maps. Types of Maps. Map Production and Symbolization

Transcription

1 Charles Minard s description of Napoleon s disastrous advance on Moscow Map Production and Symbolization Six variables visually communicated x, y, time, # of men, temperature, and direction Map Production: Cartography Definition: the art, science, and technology of making maps Outline Types of Maps Cartographic Design 1. Basic Elements 2. Layout and Design Issues 3. Some Tricks to Good Map Design Symbolization Display continuous datasets Use of colour Types of Maps Topographic Thematic Topographic Maps Relief depiction (changes in elevation) Contour lines connect lines of equal elevation Contour intervals can also be shaded to add more visual cues 1

2 Thematic Maps Typical reference map - portion of a USGS topographic quadrangle map, Bellefonte, PA. Show one type, or theme of information, e.g., population, wheat production or suitability for Lepus Millipedus!!! Ways of showing data on thematic maps: Isopleth Choropleth Cartogram Dot Proportional Symbol Isopleth Maps Isopleths are lines that connect points of equal value (e.g., temperature, precipitation amounts) Contour lines on topographic maps connect points of equal elevation Choropleth Maps Political or other units (e.g., counties, voting districts) are shaded according to the value of the theme that is mapped Usually, the map is divided into several classes of values (often 5-7) 2004 US election results (slightly modified :) Cartogram Cartograms vary the size of fthe areas being mapped to show changes in values 2

3 2004 Election results by state Choropleth Map 2004 Election results by state Cartogram by population 2004 Election results by county Choropleth Map 2004 Election results by county Cartogram by population Dot Maps Dot Map Each dot represents a given number of the theme being mapped (e.g., bushels of corn, toxic waste sites) Dot maps show detailed distributions (i.e., areas of relative concentration and sparseness) 3

4 Proportional Symbol Maps Symbols (e.g., circles, cubes) are used to show the amount or volume of something at a location Example: urban population Symbols vary in size according to the value being mapped How to create a good map? A pie chart map that depicts quantitative data Map Elements All maps should include the following Title Scale Legend North Arrow Author Date Projection & GCS 4

5 Map Elements Map Composition Need to give thought to a range of issues the user, what is the message to be communicated, etc. How much detail should I include? Map Layout and Placement Visual balance Layout that promotes well-balanced design light/dark, small/large, long/short, within/outside Depends on relative position and visual importance of map elements determines the visual weight of each item Visual balance 3:5 ratio Alignment Margins bad good 5

6 Visual balance White space Try to reduce white space Sometimes helpful to map reader breathing room Relate to affective design Bounding boxes Use to group items Use to create balance Don t overuse Creates effective design that is not free flowing Visual balance A B > A B Grouping Keep related items together N Arrow and scale bar Legend and explanatory text Map and graph Heavy elements, anchoring elements Map distributions Scale bars Source, projection, date, cartographer, funding information A B Dividing Your Map Equal divisions of space are least interesting Small spaces struggling against larger ones creates visual interest Variety and moderate amounts of complexity also creates visual interest Text Rules Put title at top: Use Title Case Map labels best in serif font (letters have tails ), with first letter upper and rest lower case place above and to the right of the feature (2nd choice: above to left) use font size hierarchy to indicate relative importance: Canada, BC, Vancouver water features traditionally labeled in italic font Figure-Ground relationships A) no perceptible figure-ground differentiation B) & C) land/water differentiation made only if you are familiar with the area being portrayed D) figure clarified by use of land-based names, graticule to lower water and separate from land, use of details on land only, good contour provided by appearance of continuous graticule beneath land surface From Robinson, Sixth Edition, page 326 6

7 Some Symbolization Options Symbolization Line weight Pattern Shading Hue Symbolization Quantitative data symbols should have visual progression corresponding to data values for polygons, use monochromatic color ramp: same color (hue), different saturation or value can highlight top and bottom with contrasting color if desired if use different fill patterns, be sure visual progression is achieved for point symbols, use different sizes of the same symbol Qualitative data For polygons, use different colors (polychromatic), or different fill patterns For point symbols, use same size of different symbols What symbols should I use? Color Qualitative Shape Texture / Pattern Graytone value Quantitative Size Dimensions of Color Human perceptual limitations? Use value to symbolize change ordinal, interval or ratio data Use a moderate level of saturation but avoid 100% saturation Hue can be used to symbolize categorical variables Maximum 12 colors Maximum 7 8 shades 7

8 Symbolization How to display continuous datasets (such as population data, thematic data using colour scales)? Pattern can be very useful! An example of subdivisional hierarchical organization in which the primary division is between humid and dry climates, with a secondary subdivision based on temperature, and a tertiary subdivision based on desert vs. steppe. From Robinson, Sixth Edition, page 330 Making Better Maps: Lines From Dent, Fifth Edition, page 249 The visual effect of varying line weights on a map is illustrated by comparing (b) and (c). More visual interest is achieved with greater contrast of weight. In this case, the figure and ground organization is strengthened. An example of extensional hierarchical graphic organization in which a set of roads is graded according to relative importance. From Robinson, Sixth Edition, page 329 8

9 Templates Extras Symbols and symbol styles 12,000 + symbols Styles Industry Specific Civic Transportation Environmental Geology Create your own Changing layer symbol properties Table of Contents or the Symbology Tab Referenced from ESRI presentation Cartography and ArcGIS Referenced from ESRI presentation Cartography and ArcGIS 9

10 Setting layer symbology Polygon symbology Same symbol for all features Based on attribute values Saving symbology to a layer (.lyr) file Properties of a point symbol Line symbology Labeling Options Labeling method Legend Properties Preparing the legend labels in Layout View Showing transparency in the legend Modifying the appearance of a legend Labeling field Label appearance Label visibility Label styles 10

11 Legend Properties cont. Exporting Options Exporting Options PowerPoint Adobe Illustrator transfer Setting your dpi 11