Presentation on theme: "Geographic Information Systems SGO 1910, 4930 November 8, 2005."— Presentation transcript:
Geographic Information Systems SGO 1910, 4930 November 8, 2005
Announcements n eSeminar in GIS: Putting the e into GI Science (Mark Birkin, Leeds). Thursday, November 17, room 3514 Georg Sverdups Hus. n Norsk ESRI brukerkonferanse 2006 Den 17. norske ESRI brukerkonferansen går av stabelen februar Konferansen byr på en rekke foredrag, tekniske minikurs, bransjeseminar og sosiale aktiviteter. Vi ser frem til spennende dager sammen med deg! Påmelding og mer informasjon kommer senere.
Announcements n Extended access to GIS lab during Nov.- Dec? n GIS Internships: Any interest?
Oslo Project Groups 1. Marita Sanni, Kristin I. Dankel, Solveig Melå + Svein Johan Hansen? 2. Åslaug Enger Olsen, Maria Lyngstad, Guro Bakke Håndlykken og Jorunn Randby (4) 3. Nina Ambro Knutsen, Ellen Winje og Leif Ingholm, Gjermund Steinskog (4) 4. Birte Mobraaten, Hans Petter Wiken, Silje Hernes and Bente Lise Stubberud (4) 5. Daniel Molin, Ida Sjølander, Anne-Lise Folland and Nicolai Steineger (4) 6. Hæge Skjæveland, Marie Aaberge, Cecilie Hirsch, Kaja Korsnes Kristensen (4) 7. Urs Dippon, Steven huiching Yip, Harald Kvifte & Eirik Waag (4) 8. Marthe Stiansen, Marielle Stigum, Tomas Nesset, Andreas Skjetne (4) 9. Andreas Dyken, Håkon Grevbo, Terje-Andre Gudmundsen, Øystein Kristiansen (4) 10. Andreas Wilhelm Westgaard, Grete Simensen og Ingvild Jøranli, Solveig Lyby (4) 11. Linda Markham, Marte Hunsdal Knutsen, Anette Nesvold, Berit Indset (4) 12. Magnus Campbell, Johannes Devik Brekke, Espen Fait, Mathias Ødegård (4) 13. Julie Aaraas, Tonje Einarsen, Anne Marie Skancke, Bård Bergland (4)
Making Maps With GIS
Introduction n Output is the pinnacle of GIS projects n Two main types of output –Maps –Visualizations (see chapter 13) n Maps are good at summarizing and communicating
What is a map? n “A graphic depiction of all or part of a geographic realm in which the real-world features have been replaced by symbols in their correct spatial location at a reduced scale.” power line
Map function in GIS n Storage n Temporary communication n Intermediate check of data n Final report
GIS Processing Transformations
Characteristics of Map n Two main types –Topographic –Thematic n Some map problems –Can miscommunicate –Each map is just one of all possible maps –Complex maps can be difficult to understand
Map Types n Point data n Line data n Area data n Volume data n Time data
Choosing a Map Type n Cartographers have designed hundreds of map types: methods of cartographic representation. n Not all GISs allow all types. n Most have a set of basic types n Depends heavily on the dimension of the data to be shown in the map figure.
Choosing the Wrong Type n Fairly common GIS error. n Due to lack of knowledge about cartographic options. n Can still have perfect symbolization. n Possibility of misinformation n Definite reduction in communication effectiveness.
Choropleth Class Schemes
Choosing Types n Check the data –Continuous –Discrete –Accuracy & Precision –Reliability n Dimension (Point, Line, Area, Volume) n Scale of Measurement (Nominal, ordinal, etc.) n GIS capability n Is there a need to supplement GIS software? (e.g. with a drawing package)
Maps and Cartography n Map – ‘digital or analog output from a GIS showing information using well established cartographic conventions’ n Cartography is the art, science and techniques of making maps
The Need for Design n To appear professional and avoid errors, GIS maps should reflect cartographic knowledge about map design. n A map has a visual grammar or structure that must be understood and used if the best map design is desired. n Cartographic conventions should be followed (e.g. forests should be green).
Map Design n Good map design requires that map elements be placed in a balanced arrangement within the neat line. n A GIS map is designed in a process called the design loop.
To be effective, a map must be correctly designed and constructed.
The Parts of a Map: Map Elements The United States of America Alaska Lambert Conformal Conic Projection Source: U.S. Dept. of State hundreds of kilometers Washington,D.C. National Capital Legend Scale Credits North Arrow Place nameInset Ground Figure Neat line BorderTitle Hawaii
Title Legend Projection Grid Data Source Inset map Map Body Author North Arrow Scale
Bertin's Graphic Primitives
Visual balance is key! n Visual balance is affected by: the "weight" of the symbols the visual hierarchy of the symbols and elements the location of the elements with respect to each other and the visual center of the map.
Visual center 5% of height Landscape Portrait
Visual Layout Title Here Eye expects (1) balance and (2) alignment
Text: Selection and Placement Kristiansand BM 232 U S R o u t e L a k e M u d POINTLINEAREA Some cartographic label placement conventions. Points: right and above preferred with no overlap. Lines: Following the direction of the line, curved if a river. Areas: On a gently curved line following the shape of the figure and upright. Bærum Oslo
Text placement Trondheim Bogstadvann Path right PathDownPathDown
Symbol “weight” Line weight Pattern ShadingHue
Map Design and GIS n When a GIS map is the result of a complex analytical or modeling process, good design is essential for understanding. n The map is what distinguishes GIS as a 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.
Limitations of Paper Maps n Fixed scale n Fixed extent n Static view n Flat and hence limited for 3D visualization n Only presents ‘complete’ world view n Map producer-centric
Conclusions n Cartography is both an art and a science n Maps are fundamental to GIS projects n Modern advances in cartography make it easy to produce good and bad maps n New technology and especially the Internet has change the content and techniques of GIS-based cartography