exam 1 Flashcards
(27 cards)
reference maps
general purpose
many geographical features
ex.) goggle maps
thematic maps
special purpose
paticular geographc phenomenon
ex.) maps of population
what is mappable?
phenomena
data
information
phenomena
stuff in the real world
data
records of observations of phenomena
information
knowledge of value obtained through the collection, interpretation, and analysis of data
Where?
location of phenomena
what?
characteristics of phenomena at that location
how?
metadata- information about how the data were collected
data model
a logical construct for the storage and retrieval of information
discrete phenomena
clearly bounded phenomenon
forms a separate entity that can only exist as a whole object
vector data model
continuous phenomena
phenomenon with a value defined for all locations
fractional parts are allowed
ex,) elevation, precipitation, air pollution
raster data model
vector data model
represents geographic features as points, lines, and polygons
used to map discrete phenomena
points
represented as a single coordinate pair
polylines (linestrings)
line are ordered lists of vertices or coordinate pairs where all coordinate pairs are unique
polygons
They are where the first and last vertex are the same
raster data model
represents geographic features as a regular grid of cells
what does each cell size indicate?
(raster data model)
they length of one grid cell
Qualitative
Nomial
ordinal
Quantitative
Interval
Ratio
Nominal
discrete non-numerical classes
cannot be order
ex.) forest type
ordinal
can be order
ranks
classes numerical or non-numerical
Interval
continous or discrete numbers
ordered
ranks
no “true” zero
ex) temperature
ratio
continous or discrete numbers
ordered
ranks
a “true” zero
ex) precipitation
