Scale

The Concept of Scale

Scale is the size or extent of something
The temporal scale is the length of time
The spatial scale si the physical size or extent

Spatial Scale

1. Cartographic Scale

The ratio of the distance on the map to the distance in the physical world
Three types of Cartographic Scale:

WordS describe UNITS of distance on map compare to UNIT of distance in physical world
Rarely used outside printed paper maps

Scale bar visually equates a map distance (No UNITS) to a distance in the physical world (WITH UNITS)
Still works if you enlarge a static map (a paper map or an image of a map)

Ratio of map distance (NO UNITS) to physical distance (NO UNITS)

In cartographic scale:

Small scale is ZOOMED OUT; large,global, or extensive
Large scale is ZOOMED IN; detailed and localized

2. True Cartographic Scale

True cartographic scale means that scale on the generating ellipsoid and the developable surface are equal
True cartographic scale is only found on the standard line(s) - the line(s) of contact with the developable surface OR emanating out from the point of contact
True cartographic scale is what is shown on a map (either through verbal scale, scale bar, or representative fraction). This is called the Principal Scale

3. Principal Scale vs. Actual Scale

Due to the distortion from the distance from the 3D to 2D projection process, the ratio of between distances on the ellipsoid and map become skewed away from the point/line(s) of contact:

Look at this example: At the Equator, the principle scale is equal to actual scale. But with the increment of altitude, the scale becomes large due to ellipsoid.

4. Scale Factor

The Scale Factor is the ratio of scale on the map (Actual scale) to scale on the ellipsoid (Principle Scale)

SF = \frac{Actual\,Scale}{Principal\,Scale}

4. Scale In traditional Studies

Traditionally, scale was the backdrop or setting of geographic studies, but not analyzed as a factor in social spatial relationships or as an object of study in its own right
Traditionally recognized scales:
- Global
- National
- Regional
- Local

5. Modern Conception of Scale

Scales are not fixed but are socially contingent
The structure of scales is political and subject to change: the “politics of scale”
Key players in scalar politics: state, capital, other groups
The scale just above may not be the best way to effect change: “jumping scale”
Scalar configurations have material consequences

6. Scale of Analysis

The spatial unit of analysis, such as county, city council district, census tract, census block, neighborhood, or other governmental districts; or grid size