Map, generalisation, map design

• Desktop GIS software is installed on a computer and provides advanced GIS capabilities for data analysis and visualization.
• What is a Map?

  Map is a representation of a place, so that readers can have better understanding of place. It is a two-dimensional representation of a particular place. Also, it is a symbolic interpretation of place and highlight the relationship between elements in spatial context. On a map, features / things are most simplified as possible.
• Different maps show different information and use different symbols to represent the features of the environment, which are explained in a map's legend.
• Types of maps


  • Sketch maps
  • Topographic maps
  • Thematic maps
  • 3D maps
• Topographic maps


  • Contain a diverse set of data on different themes like land use, relief and cultural features.
• Thematic maps


  • Show data relating to a particular theme or topic, such as soil, geology, geomorphology, land use, population or transport.
• Qualitative map data


  Data in the form of a quality that expresses the presence or absence of the subject on a map, like the kind of vegetation present occupying a region.
• Quantitative map data


  Data expressed as a numerical value, like elevation in meters, or temperature in degrees Celsius.
• Mapping process


  1. Think of the purpose the map is to serve

  2. Determine the scale

  3. Choose the features to portray

  4. Select a method for the representation in two dimensions

  5. Adopt a map projection

  6. Apply a spatial referencing system

  7. Annotate the map with keys, legends and text
• Generalization


  The process of reducing the amount of detail on a map in a meaningful way to make the map easier to read.
• Types of generalization


  • Graphic generalization (simplification, enlargement, displacement, or merging of geometric symbols)
  • Conceptual generalization (dealing with the attributes and requires knowledge of the map contents and the principles of the themes mapped)
• Spatial entities


  • Points
  • Lines
  • Areas or polygons
• Point


  Used to represent features that are too small to be represented as areas at the scale of mapping being used.
• Line


  Used to represent features that are linear in nature, for example roads, power lines or rivers.
• Area or polygon


  Used to define features such as fields, buildings or lakes.
• Mapping methods for thematic maps

  • Chorochromatic maps
  • Choropleth maps
• Chorochromatic maps


  Render nominal values for areas with different colors, with no suggestion of hierarchy or order.
• Choropleth maps


  Values are calculated for areas and expressed as stepped surfaces showing a series of discrete values, with differences in intensity of a color denoting the differences in the phenomenon. A hierarchy or order between the classes can be perceived.
• GIS data have two component parts: attribute descriptions (in attribute tables) and spatial extent (abstracted in the form of a map).
• Spatial dimensions


  • Point
  • Line
  • Area
  • Volume
• Levels of measurement


  • Categorical data (nominal, ordinal)
  • Numerical or continuous data (interval, ratio)
• Graphic primitives


  Visual resources used by cartographers to reduce the world to points, lines, and areas, including size, shape, value, saturation, texture or pattern, hue, orientation, arrangement and focus.
• Most mapping or Geographic Information System (GIS) software provide mapping and design tools, but you need to know cartographic principles to make a map that can communicate effectively.
• Map design guidelines


  • Graphic hierarchy (foreground vs. background)
  • Color logic (warm vs. cold colors)
  • Geographic context (map elements that provide critical information to readers)
  • Visual balance (map layout)
  • Lettering (readability of text on a map)
• Graphic hierarchy


  The shift between figure and ground provides the basis for the interpretation of map elements.
• Color logic


  Colors are applied according to the types of measurement: binary, qualitative, quantitative, or diverging (data that span across two extremes).
• Visual balance


  Map elements should be distributed as evenly as possible within the map frame to avoid unnecessary crowding or large blank areas.
• Lettering


  Influenced by font, font variation, font size, font orientation, text placement, and amount of anti-aliasing.
• Map design process: Planning

  Determine the information to convey, if a map is the best way to communicate it, the problems or questions to address, the information to include, data availability, the intended audience, and the reality of resources (money, materials, equipment, labor, & time).
• Map design process: Composing構成

  Decide on visual dominance of map elements, final map size, reproduction method, title/caption, contribution of each element, base information, need for a legend, communication of intended patterns, and complexity level.
• Map design process: Editing and Proofreading

  Check for sources of statistical or borrowed data, typographic/grammar/spelling errors, geographical errors, legibility and readability, visual hierarchy, coherence of map elements, and potential simplifications.
• Media considerations

  • Paper (A4, A2 to A0), softcopy (white, dark, colored backgrounds), films or transparencies (transparent background)
  • Colors (CYM, HLS, RGB)
  • Interactive, animated or printed map
• Conceptual Generalization -natural break (arranged by system itself) -equal interval (range is equally distributed) -equal frequency (same happening pattern)
• Why scale matters?

  scale helps reader to understand the *relative size and distance on map. Suitable data geometry is dependent on scale. maps are smaller than reality being mapped. It is also associated with level of details, when scale decreases, level of detail decreases. Thus, scale would affect the amount of information visualized on map based on the purpose and intended audience.
• Where will scale provide?

  a less prominent (important) part of map
• Source / credits

  • for transparency purpose // provide attributions to person / company/ agency
• why source / credits are important to readers?

  1.accuracy and readability (trustworthy) 2.possible for readers to find / explore data further if necessary
• Question type on quiz/exam: Is it a good or bad map?

  aspects that can be used: -map design guidelinesss (1.lettering (font size, font type, text placement, font orientation) 2.visual balance ('less is more" avoid unnecessary crowding / elements should be distributed EVENLY / avoid LARGE BLANK area) 3.graphic context (map elements provide info) 4.color logic (use of hue: warm / cold colour_ // colour scheme (other card will mentioned) 5. graphic hierarchy (shift b2 figure and ground -->2 interpretations)
• Color scheme

  -according to the type of measurement of data -->binary (2 distinct colors ; 2 bits) / discrete / qualitative data (2 or more distinct colors) / quantitative data (intensity of colors/ color gradient) / diverging (visually emphasizing the polarity 兩極性, easier to interpret)
• Types of graphic primitives?

  1.value 2.size 3.shape 4.hue 5.orientation 6.texture 7.arrangement 8.saturation 9.focus