13) Models and Overlay Analysis Flashcards
(18 cards)
________ a simplification of reality that is constructed to gain insights into select attributes of a physical, biological, economic, or social system.
MODEL
________ a formal representation of the behavior of system processes, often in mathematical or statistical terms.
MODEL
“ALL MODELS ARE WRONG, BUT SOME ARE USEFUL”
GEORGE E.P. BOX
________ is a group of methodologies applied in optimal site selection or suitability modeling.
Overlay Analysis
Steps in Understanding Overlay Analysis
- Define the problem
- Break the problem into sub-models
- Determining significant layers
- Reclassification/Transformation
- Weight
- Add/Combine
- Analyze
Spatial Data Types
- Vector Data
- Networks
- Raster Data
________ uses coordinate pairs to define both the location and shape of geographic features.
Vector Data
________ are specific type of vector data and are comprised of a set of connected features in a system.
Networks
________ represents geographic space as a grid of cells, with each cell being assigned a value representing the attribute for that particular location.
Raster Data
Accounting for Spatial Bias
- Spatial Autocorrelation
- Correlated Layers
“Everything is related to everything else, but near things are more related than distant things.”
Tobler’s First Law of Geography
________ determined by the phenomenon being modeled.
Geographic Extent and Resolution
- GIS data has both a spatial component and attribute component.
- correct location and correct attributes are important to ensure results are valid.
Data Quality
Overlay Methods
- Feature/Vector Overlay
- Raster Overlay
Feature/Vector Overlay Tools
- Identity
- Intersect
- Symmetrical Difference
- Union
Raster Overlay Tools
Weighted Sum
Weighted Overlay
Fuzzy Overlay
Fuzzy Membership Types
A – Large
B – Small
C – Gaussian
D – Near
E - Linear
________ is a way to perform spatial analysis by creating expressions in an algebraic language.
Map Algebra
