Midterm Flashcards
used to show a particular area associated with a certain geographic area
Thematic Layers
the art and science of making maps.
cartography
a type of map that shows the location of features
reference maps
a type of map that uses lines of equal value to show a quantity
Isarithmic maps
The types of values that Isarithmic maps generally show
pressure, elevation
a type of map that shows a particular theme associated with a certain area
thematic maps
a type of map that shows movement or migration using arrows.
flow map
a type of color scheme that varies the color hue for different values
qualitative
a type of color scheme that displays data with trends in one direction (0%-100%)
sequential
a two-way color scheme that represents extreme values and a mid-range
diverging
a type of data represented by names (city names, crop type, land cover type)
qualitative data
a type of data represented by numbers and statistics (temperature, population density, crime rate)
quantitative data
a level of measurement in cartographic data that measures place names, zip codes, and school names
Nominal
a level of measurement in cartographic data that measures small or large towns
ordinal
a level of measurement in cartographic data that measures continuous data with no absolute zero, such as temperature
interval
a level of measurement in cartographic data that has a net zero quantity or “real” zero, such as population density
ratio
a classification scheme that usually represents percentages or temperature values
Equal Interval
a classification scheme that prefers ordinal data and where outliers are not as obvious
Quantiles
a classification scheme where bins show how much data differs from the average
Mean-Standard Deviation
a classification scheme where algorithms attempt to find “natural breaks” in data
Jenks
specifies a point on latitudinal and longitudinal degrees, and cannot show distance or length
Geographic coordinates
a three-dimensional surface where the surface is the mean sea level
geoid
earth surface which is modeled as an oblate spheroid
ellipsoid
a system for anchoring an ellipsoid to surveyed points by having contact with the surface of the earth
datum
height above geoid
orthometric height (H)
height above ellipsoide
ellipsoidal height (h)
National Geodetic Vertical Datum of 1929 (NGVD29), Current: North American Vertical Datum of 1988 (NAVD88)
commonly used vertical datums
a synthetic rendering of locations from the curved earth surface onto a flat map surface
map projection
a type of projection that is positioned at the poles. distortion increases when away from poles, and it can’t show more than half the world.
planar projection