Term
| What is Geographic Information Science? |
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Definition
| A field of study which examines the representation, storage, analysis, visualization of geographic information. -->seeks to redefine geographic/concepts |
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Term
| What is a geographic information system? |
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Definition
| GIS aids in the collection, maintenance, storage, analysis, output, and distribution of spatial data and info. |
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Term
| Spatial Representation (Conceptual level) |
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Definition
| Real-world things are entities (geographic themes); conceptualizations of spatial entities governed by how we perceive/interpret that entity and its intended application in GIS |
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Term
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Definition
discrete entities with boundaries and location explicitly defined; modeling the human/urban landscape; e.g. city
Can include spatial info and attribute associated with the object; e.g. within a city boundary there are streets, building locations, waterways, etc. |
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Term
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Definition
A collection of spatial distributions that vary continuously across space; e.g. natural modeling
continuously varying features; e.g. elevation
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Term
| What is the false dichotomy(logical fallacy) between the object and field views? |
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Definition
1. Both views can be used to rep. the same entity....they aren't mutually exclusive in representing geographic phenomena
E.g-->lakes could be represented as discrete objects w/ defined boundaries (shorelines)
Lakes could also = continuous distribution of the degree of "lakeness"; e.g dry, seasonally wet, perennially wet, etc.
THIS ALL DEPENDS ON CREATORS PERCEPTION OF PHENOMENA and its application |
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Term
| Spatial data models are.... |
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Definition
a representative form of the conceptual view.
They are real-world observations modeled by spatial geography (COORDINATES) and attributes (DATA AND TEXT THAT DESCRIBE CHARACTERISTICS OF FEATURES) |
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Term
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Definition
points, lines, polygons
location explicitly defined by pairs of coordinates (point is the basic building block) |
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Term
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Definition
cells
location implicit by the size/area of the cell/ cell layout (cell is the basic building block) |
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Term
| Vector models are best represented in.... |
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Definition
| object view. It is best for discrete data with well-defined boundaries |
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Term
| Raster models are best represented in.... |
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Definition
field view
Raster models are best for continuous data |
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Term
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Definition
| the same view can be converted and modeled in both raster models AND vector models |
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Term
| Key features of spatial data are...... |
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Definition
1. Georeferenced to either a geographic or projected coordinate system
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Term
Key features of spatial data are......
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Definition
2. defined by a particular map scale(an original scale of capture)
i.e. spatial resolution |
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Term
Key features of spatial data are......
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Definition
3. smaller than the reality they represent
limits the amount of detail |
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Term
Key features of spatial data....
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Definition
| 4. Involve some level of generalization/simplification (error of omission) |
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Term
Key features of spatial data are......
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Definition
5. defined by characteristic scale of use or application
(governed by its map scale) |
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Term
Key features of spatial data are......
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Definition
6. flawed b/c of our conceptualization/definition of an entity, its intended purpose, and/or by limits of technology for "capturing" that entity
e.g. satellite resolution |
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Term
| Vector dimensionality and properties are.... |
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Definition
zero dimensional (No length or area; point/node)
One dimensional (length, no area; line segment, arc)
two dimensional (length, area; polygon)
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Term
| The chosen dimensionality of a geographic representation in a vector model are influenced by..... |
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Definition
MAP SCALE
(river is a point at 1:5,000,000)
(river is a line at 1:500,000)
(river is a polygon at 1:5,000) |
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