Cartography and Visualization Flashcards
Thematic Map
A type of map that is especially designed to show a particular theme connected with a specific geographic area.
Choropleth Map
A thematic map where geographic regions are colored shaded or patterned in relation to a value, relying on boundaries.
Proportional Symbol
symbol drawn proportional in size to the size of the variable being represented
Isarithmic
Isopleth. Lines of equal value are drawn (such as contour maps) or ranges of similar values are filled with similar colors or patterns, relying on the density of the variable.
Dot Map
It shows the distribution of the phenomena where values and locations are known, placing a dot where the location of the variable is.
Dasymetric Map
An alternative to choropleth, which is ancillary information is used to model the internal distribution of the phenomenon.
Multivariate display
Putting more than two sets of data on one map
Web Mapping
The process of using maps delivered by GI. Web maps are both served and consumed.
Map Layout Elements
title, map, legend, scale, supporting media, north arrow, metadata (source, currency of the information, projection, copyright, and authorship)
Symbols
That represents things on a map
Map Accuracy
It’s difficult to assess, as all maps show a selective view of reality. Instead, we should ask if the map is appropriate for our purposes.
Map Scale
1:100 - One inch represents 100 inches in the real world (but actually unitless). Large scale is more zoomed in and shows more details than small scale.
Symbolization variables
size, shape, orientation, pattern, hue, value
Quantitative variable on map
can be represented by the size/thickness/hue/ color shades of their symbols.
Qualitative variables on map
can be represented by the shape, pattern (dash line vs. the straight line), and hues.
Typography
The design of the text, point size, line length, and typefaces.
Verbal scales
express in words a relationship between a map distance and ground distance, such as “ one inch represents 16 miles”.
Visual scales
a graphic scale or bar scale
Representative scales
it’s a representative fraction or ratio scale, such as using “1 inch = 24,000 inches” to represent “1:24,000”
Absolute scales
The system of measurement begins at a minimum or zero point and progresses in only one direction (which is the form of a map scale that the scale starts from 0 and expands to the right side with only positive numbers on the ticks)
Relative scales
It begins at some point selected by a person and can progress in both direction
Display v. Data
The data is built at a certain scale/accuracy but once the data is displayed in any other format than the one it was made for, the scale gets warped, such as a map made as 9’‘*10’’ that is then scaled down and printed in a newspaper.
3D Mapping
Typically the z value is the elevation.
Contour Line
Isoline, isopleth, or isarithm. This function of two variables is a curve along which the function has a constant value. It joins points of equal value on a line.
Contour interval
Difference in elevation between successive contour lines
Index Contour
The contour that is thicker and typically labeled
Iso
It means equal, and in a contour map, it means the equal distance between two lines.
