exammistrerm Flashcards
(167 cards)
Give 3 examples of areas of study that benefit from GIS
City and Regional Planning
Hydrologic Modeling
Security
Geotechnical Engineering
Transportation
Marketing
Real Estate
Business
Politics
Environmental Studies
discrete vs continuous data
discrete objects: objects exist in a defined location
continuous: data exist everywhere
What is the kind of data that exists in a defined location?
discrete
Define discrete data and give two examples
Discrete data are objects in the real world with specific locations or boundaries. Examples include houses, cities, roads, countries, canoe shelter locations
What is the name for data that exists anywhere?
Continuous
Canoe shelter locations is an example of what kind of data?
Discrete
Define continuous data and give two examples
Continuous data represent quantities that may be measured anywhere on the earth. Two examples include temperature or elevation
An elevation raster is an example of what kind of data?
continuous
What are stored map objects?
features
What are features and what three basic shapes do they consist of? Give an example of a feature
A spatial object composed of one or more XY pairs and having one or more attributes in a single record of an associated table. Features can be lines polygons or points.
Examples of features include a point feature representing a well or weather station, a line feature representing linear object like a rotor River, a polygon feature representing a closed area like a country or state
What is a collection of similar features with the same attributes stored together in a spatial data file, like states or rivers?
feature class
What is a feature class and give an example
A set of similar features stored together for example a United States feature class comprising of the 50 states
___ is a a set of similar objects with the same attributes stored together in a spatial data file
feature class
In the ____ model, Spatial features linked to table by unique identifier (FID or OID)
vector
What is the vector model
A spatial data storage method in which features are represented by one or more pairs of XY coordinate values forming points lines or polygons
In the ____ model, Geographic space is quantized into uniformly-sized discrete units, called pixels or cells
raster model
What is a raster
A data set composed of an array of numeric values each of which represents the condition in a square element of ground
Name at least two strengths of the vector model:
Can store individual features such as roads or streams with a high degree of precision
Linked attribute table provides capability to store and manipulate feature attributes
Suitable for mapmaking due to great feature detail
Ideal for network modeling
What is a weakness of the vector model?
Poorly suited to map continuous data
Some analysis can be time consuming (updating county level parcel data)
_______ is the ratio of distance on the map to distance on the ground
map scale
A ____ scale map covers a larger geographic region such as the world
small
a ___ scale map covers a relatively small geographic area
large
Does a small-scale map cover a large or small geographic area?
large
Does a large-scale map cover a large or small geographic area?
small