Lecture07

Lecture07 - Making Maps With GIS Making Maps With GIS 8.1...

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Unformatted text preview: Making Maps With GIS Making Maps With GIS 8.1 The Parts of a Map 8.2 Choosing a Map Type 8.3 Designing the Map Getting Started with GIS Chapter 8 The cartographer’s paradox What is a map? “A graphic depiction of all or part of a geographic realm in which the real-world realfeatures have been replaced by symbols in their correct spatial location at a reduced scale.” scale.” Complete accuracy & completeness Complete – Position – Attribute – Timely – Scientific rigor Effective communication Effective Easy to read and interpret (intuitive) Easy Hard to misread (fault tolerant) Hard power line 1 Producer’s Responsibility Map function in GIS Storage Storage Temporary communication Temporary Intermediate check of data Intermediate Final report Final Use in the field Use To be effective, must be correctly designed and constructed The Parts of a Map: Map Elements The medium is the message Paper Film Mylar Monitor Projection Broadcast TV Internet THE DISPLAY IS PART OF THE SYMBOLIZATION 2 Cartographic Elements Medium Medium Figure Figure Ground Ground Reference information Reference Cartographic Elements (3) Page coordinates Page Ground elements Ground Graticule/Grid Graticule North arrow North Cartographic Elements (2) Border and “collar” Border collar” Neatline Neatline Insets Insets – Scale up – Scale down Metadata e.g. index Metadata Off-map references Off- Cartographic Elements (4) Figure Figure Point/Line/Area symbols Point/Line/Area Text Text Place Names Place Title Title 3 Cartographic Elements (5) Reference Information Reference Scale Scale Projection(s) Projection(s) Sources (2) Sources Credits Credits Legend Legend Reliability Reliability Text: Selection and Placement Map “impact” Distribution of Employment by State 2010 Distribution USA: Employment Distribution 2010 USA: U.S. Employment: 2010 Distribution America at Work America Where the Jobs are Today Where America’s Great Recession America’ Choosing Elements Map research Map Map compilation Map Worksheet Worksheet Selection Selection Placement Placement Layout Layout Tools in GIS not ideal Tools 4 Choosing a Map Type Cartographers have designed hundreds of Cartographers map types: methods of cartographic representation. Not all GISs allow all types. Not Most have a set of basic types Most Depends heavily on the dimension of the Depends data to be shown in the map figure. Map Types: Point Data Choosing the Wrong Type Fairly common GIS error Fairly Due to lack of knowledge about Due cartographic options Can still have perfect symbolization Can Possibility of misinformation Possibility Definite reduction in communication Definite effectiveness Reference Map Reference Reference Topographic Topographic Dot Dot Picture Symbol Picture Graduated Symbol Graduated 5 Topographic Map Picture Symbol Map Dot Map Graduated Symbol Map 6 Map Types: Line Data Origin of Flow Maps Harness, H. D. (1837). Atlas to Accompany the Second Report of the Railway Commissioners, Ireland. Dublin: Irish Railway Commission. Minard, C. 1869. Napoleon’s retreat from Moscow Network Network Flow Flow Isopleth Isopleth Reference Reference Flow Maps Symbolizing flows 7 Flow Map: Truck traffic Map Types: Area Data Choropleth Choropleth Area qualitative Area Stepped surface Stepped Hypsometric Hypsometric Dasymetric Dasymetric Cartogram Cartogram Reference Reference Choropleth Continuous/Unclassed Choropleth 8 Area Qualitative Map Stepped Statistical Surface Hypsometric map Dasymetric 9 Cartograms Map Types: Volume Data [Isopleth, Stepped Surface, Hypsometric] Isopleth, Gridded fishnet Gridded Realistic perspective Realistic Hill-shaded HillImage map Image Isoline Map Fishnet or Gridded Perspective View 10 Realistic Perspective View Hill-shaded Relief Map Image Map Map Types: Time Multiple views Multiple Animation Animation – Moving map – Fly thru – Fly by 11 Cartographic Animations Spatialization: SOM http://www.ncgia.ucsb.edu/projects/gig/v2/About/abImages/apps/sb_growth.gif http://www.aaronkoblin.com/work/faa/us.html Skupin, A. (2002) A Cartographic Approach to Visualizing Conference Abstracts. IEEE Computer Graphics and Applications. 22 (1): 50 - 58. Wordle Map Type and Dimensionality 12 Choosing Types Check the data Check – Continuous – Discrete – Accuracy & Precision – Reliability Dimension (Point, Line, Area, Volume) Dimension Scale of Measurement (Nominal etc.) Scale GIS capability GIS May need to supplement GIS software May Example: Choropleth Mapping Data should be AREA (e.g. States) Data Data should not suffer from area effect. Data Population? Population? Per capita Income? Per Elevation? Temperature? Elevation? Boundaries unambiguous. Boundaries Areas non-overlapping. Areas non- Data Scaling (Stevens) Nominal (Name of a place) Nominal Ordinal (Small, med., large town) Ordinal Interval (Arbitrary zero e.g. Sea Level) Interval Ratio (Absolute zero e.g. dollars, densities) Ratio Classification Equal Interval Equal Natural groups Natural N-tiles Equal or unequal? Equal Logarithmic? Linear? Discontinuous? Logarithmic? How many classes? How Non-overlapping, distinctive groups. Non- 13 The Need for Design To appear professional and avoid errors, To GIS maps should reflect cartographic knowledge about map design. A map has a visual grammar or structure map that must be understood and used if the best map design is desired. Cartographic convention (e.g. forests should Cartographic be green). Symbolization Errors with a GIS Map Design A GIS map is designed in a process called GIS the design loop. Good map design requires that map Good elements be placed in a balanced arrangement within the neat line. 14 The Design Loop Graphic Editors Create map layout as macro Create Draw on screen (proof plot) Draw Look Look Edit macro Edit Repeat until happy Repeat Make final plot Make Graphic Editor Software Third Party Design Software Vector Vector – – – Adobe Illustrator CorelDraw Freehand Raster Raster – – – – Photoshop CorelPaint Fractal Paint GIMP 2.0 15 Map Design (2) Visual center Visual balance is affected by: Visual the "weight" of the symbols the the visual hierarchy of the symbols and the elements the location of the elements with respect to the each other and the visual center of the map. Visual Layout Alignment Title Here Title Here Eye expects (1) balance and (2) alignment 16 Symbol “weight” Line weight Pattern Shading Color and Map Design Color is a complex visual variable and in a GIS is Color specified by RGB or HSI (CMYK 4-color) values 4Red, Green, Blue are additive primaries Red, Magenta, Cyan and Yellow are subtractive Magenta, primaries May support transparency layer May Saturation and Intensity map better onto values Saturation than hue Figure/ground relationship critical Figure/ground Hue Color printing composites GE Transparency/Opacity Cyan Magenta C M Y K Yellow 17 Dimensions of Color Simultaneous Contrast HUE INTENSITY SATURATION Simultaneous Contrast Illusion Color Primaries Subtractive color Additive color 18 Design Assistance: ColorBrewer Text placement Santa Barbara Santa Barbara Path right Santa Barbara Santa Barbara Lagoon Scale and Generalization P a t h D o w n Multivariate data Smaller scale means fewer features. Smaller Smaller scale means smoother features. Smaller Smaller scale means combining features. Smaller Smaller scale means displacing features. Smaller Often scales are mixed or over-generalized. Often over- 19 Small multiples Geovisualization software Mixing Symbols Visual analytics: the science of analytic reasoning, facilitated by interactive visual interfaces. http://vita.itn.liu.se/gav/gav/1.174303/GAV-Demo.png http://vita.itn.liu.se/gav/gav/1.174303/GAVhttp://www.natural-environment.com/images/blog/space_junk_2.jpg http://www.naturalhttp://kottkegae.appspot.com/images/taxi-flow-nyc.jpg http://kottkegae.appspot.com/images/taxi- flowhttp://ajperez.net/Images/InfoViz_small2.gif http://ajperez.net/Images/InfoViz_small2.gif http://2.bp.blogspot.com/_InzW19CnouI/SaMDNpGClZI/AAAAAAAAAA8/3DGaPvuW7-Q/s1600-h/GriffeyWordle.png http://2.bp.blogspot.com/_InzW19CnouI/SaMDNpGClZI/AAAAAAAAAA8/3DGaPvuW7-Q/s1600http://www.perceptualedge.com/blog/wp-content/uploads/2009/01/horizon-graph-large.jpg http://www.perceptualedge.com/blog/wp- content/uploads/2009/01/horizon- graph- 20 Map Design and GIS When a GIS map is the result of a complex When analytical or modeling process, good design is essential for understanding. The map is what distinguishes GIS as a The different approach to the management of information, so extra care should be taken to improve the final maps that a GIS generates in a GIS task. Coming next… How to pick a GIS How 21 ...
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This note was uploaded on 12/28/2011 for the course GEOG 176a taught by Professor Clarke during the Fall '09 term at UCSB.

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