GIS for Environmental GIS for Environmental ScienceScience

ENSC 3603ENSC 3603

Class 19Class 193/24/093/24/09

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• “A graphic depiction of all or part of a geographic realm in which the real-world features have been replaced by symbols in their correct spatial location at a reduced scale.”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

Back

Visualization of Geographic Visualization of Geographic Information Information

• Cartography - The art or technique of making maps or charts.

• GIS and Cartography are linked by their common focus on maps

Conventional CartographyConventional Cartography

Real World

Cartographer’sInterpretation

Map

Map reader’sinterpretation

GIS information communicationGIS information communicationReal World

Conceptual Data model

Logical Data model

Physical Data Model

GIS Spatial Database

Spatial Informationoperator Products

UserUser feedback

control

Cartographic Design in GISCartographic 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

ColorColor

• 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

TextText

• Formed from• Family – set of similar typefaces

Times new Roman, Arial, Impact • Face or style – the specific variation based on

weight width and angleBold 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 SetsSymbols and Symbol Sets

ESRI, Learning ArcGIS 9 | Creating Map Symobology

Map-to-Page TransformationMap-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 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 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 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 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 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 DoRead 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 26th

• 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