GIS for Environmental Science ENSC 3603 Class 19 3/24/09

Topics for Today Map Function Map Elements Cartography Cartographic Design in GIS Map layout and design Geographic contents of a map Cartographic Generalization

What is a Map “A graphic depiction of all or part of a geographic realm in which the real-world features have been replaced by symbols in their correct spatial location at a reduced scale.”

Map function in GIS Storage Temporary communication Intermediate check of data Final report To be effective a map must be correctly designed and constructed

Map Elements Back

Visualization of Geographic Information Cartography - The art or technique of making maps or charts. GIS and Cartography are linked by their common focus on maps

Conventional Cartography Real World Cartographer’s Interpretation Map Map reader’s interpretation

GIS information communication Real World Conceptual Data model Logical Data model Physical Data Model GIS Spatial Database Spatial Information operator Products User User feedback control

Cartographic Design in GIS Output can be paper maps or computer screen Use of Color Use of Text Symbols and Symbol Sets Map-to-Page transformation

Color Color is made from color (hue), lightness (value), and the purity of hue (saturation) Color (Hue) Lightness (Value) range of light to dark Purity of hue (Saturation) Colors combine well with other variables Has visual attraction Easy to remember May be unnecessary Expensive to print

Text Formed from Family – set of similar typefaces Times new Roman, Arial, Impact Face or style – the specific variation based on weight width and angle Bold or italic Font – refers to a character set with particular style and at a specific size Times New Roman (20) Times New Roman (32)

Symbols and Symbol Sets ESRI, Learning ArcGIS 9 | Creating Map Symobology

Map-to-Page Transformation Is the placement of layer features onto an output medium of a specific size. Physical page Graphics page Map limits Map extent

Map Layout and Design Basic map elements: Information needed by the map reader Elements that are found in virtually all maps: Map Figure, Legend, Distance or Scale, Direction, Sources of information and how map was processed Elements that are sensitive to context: Title, Projection, Map creator, Date of production Elements that are used selectively to assist effective communication: Neat lines, Inset maps, index maps, Locator maps.

Map Layout and Design The most important information is generally larger and toward the upper left of the page. Less important elements are positioned to the right and down the page. Each map element needs to provide the essential function of improving reader comprehension. Guard against to much detail – this may confuse the reader and make the map difficult to comprehend in a reasonable amount of time.

Geographic Contents of the Map A good design for geographic contents contains: –Visual balance With other map components to improve the reading of the map –Visual clarity Resolve spatial conflicts. This usually involves generalization –Visual hierarchy Appropriate choice of font and symbol size

Geographic Contents of the Map –Visual contrast Appropriate use of color and patterns –Context The selection of the appropriate layers to present in the map figure –Effective label placement Important because it affects the readability of the map Guidelines for label placement: Lo (2007) p. 264.

Cartographic Generalization Map generalization is needed to simplify the map to improve readability and aesthetic appeal A small-scale map is usually more generalized than a large-scale map Index and locator maps can be used to orient the reader and reduce the size and amount of information in the main map figure

Read and Do Read Chapter 7 in Lo (2007) especially section 7.5. Review ArcGIS 9 ESRI course Module 2 Review progress on your Project Study for exam on Thursday the 26 th Today’s material will not be on the test.

“Challenges are what make life interesting; overcoming them is what makes life meaningful.” Joshua J. Marine “You may forget how you behaved when the going got tough, but others won't.” Mark Burnett