Map Symbolism
- Map symbolism has become pretty standardized through the centuries, so that even foreign maps are not all that hard to read
- The important need for map symbols is that they be readily recognizable & suited to the scale of the map
- Map symbols are into 3 major categories:
- pictorial symbols
- colors symbolism
- value symbols
Map Symbolism | 1. Pictorial Symbols
- Involves using neat little pictures to express what is found at a particular place on a map;
- such as a building, a well or spring, or a mine
Map Symbolism | 2. Color Symbols
- Color symbolism has pretty common usage
- Blue depicts water features: rivers, springs, lakes, playas, oceans, reservoirs, canals
- Green represents vegetation (both natural and human-maintained): forests, marshes, scrublands,orchards, vineyards
- Brown shows topography or terrain
- Black shows human artifacts, such as individual buildings, outbuildings, railroads, pipelines, power lines, oil wells, and tanks
- Red shows larger human artifacts, such as highways, roads, townships, and urban built-up areas on relatively smaller scale maps
Map Symbolism | 3. Value Symbols
- Value symbols; used to identify something, show it's location, and to tell us something about its amount
- The Quest to represent change in values across space has led to different map types;
- Dot maps: shows amounts of something, in a location using concentrations of dots. Each ⬤ might stand for one case, or multiples (e.g., ⬤ = 10 hectares of wheat; ⬤ = 1,000 head of cattle)
- Graduated symbol maps: draws reader's eye directly to big concentrations of distribution that vary in size, somehow proportionately to the concentration in an area
Map Symbolism | 3. Value Symbols
- Divided circle map: shows the relative value of something by the size of the graduated symbol but also breaks that symbol up in a way that allows its composition to be seen
- Bar chart maps: shows the relative local importance of various categories by the relative height of the bars
- Flow maps: show the origin(s) of some flow (e.g., water, money, oil, migration of animals or humans), its destination(s), and its magnitude by arrow symbols which point from some places to others and vary in thickness
Map Symbolism | 3. Value Symbols
- Cartograms: are bizarre-looking maps, in which the areas of spatial features are distorted (shapewise, relative position maintained) in proportion to the value of an attribute
- Choropleth maps: are simple maps that represent categories of themes of interest. (e.g., rock types, soil types, vegetation types, types of agriculture, climates, or such human phenomena as language areas, dominant religions, population density, wealth and poverty, numbers of executions)
Map Symbolism | 3. Value Symbols
- Isoline map (or isarithms or isopleths): Isoline is a line on a map, that connects all places with the same value of "something". Be it rainfall, air pressure, elevation, or .... latitude and longitude! Meridians are isolines of longitude, and parallels are isolines of latitude
- Haptic maps: use sound to convey information. They can be used to allow visually-challenged people to make use of maps
-- End of Lecture 8 --
Cartography & Visualization II
That’s it!
Queries about this lesson, please send them to: jmwaura.uni@gmail.com
***References***
- Mapping, Society, and Technology, Steven Manson
- Web Cartography, Map Design for Interactive and Mobile Devices, Ian Muehlenhaus
- Web Cartography, Menno-Jan Kraak and Allan Brown, ITC
- Cartography, Thematic Map Design, Borden D. Dent
- GIS Cartography, A Guide to Effective Map Design, Gretchen N. Peterson
- Thematic Cartography and Geovisualization, Terry A. Slocum et.al
Courtesy of reveal.js