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Outline
Looking back to raster-based spatial analysis
Analogies in vector-based spatial analysis
Other vector-based analysis functions
GmE 203 Principles of GIS
Lecturer: Ariel C. Blanco, Dr.Eng.
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Raster-based Spatial Analysis
How do they work?
Analogies in Vector-based Spatial
Analysis
Querying
Clipping, Masking
Georeferencing
Proximity analysis
Overlay analysis
Terrain analysis
Cell statistics
Neighborhood analysis
Zonal analysis
Visibility analysis / Viewshed mapping
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Querying
Attribute/Spatial Query
Clipping, Masking
Clipping
Georeferencing
Spatial Adjustment
Proximity analysis
Buffers
Overlay analysis
Union, Intersection, Spatial Join
Terrain analysis
Based on TIN
Cell statistics
No equivalent
Neighborhood analysis
Point, Line Statistics
Zonal analysis
No direct equivalent
Visibility analysis / Viewshed mapping
3D Visibility Analysis
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Attribute & Spatial Query
(Selection)
Spatial Query (Selection by
Location)
Attribute query (Selection by Attribute)
Spatial query (Selection by Location)
Spatial relationship
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Spatial Query (Selection by
Location)
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Spatial Query (Selection by
Location)
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Spatial Query (Selection by
Location)
Clipping
Removes data
outside the area of
interest (AOI)
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Buffers
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Buffers
Creates buffer polygons around input features to a
specified distance. An optional dissolve can be
performed to combine overlapping buffers.
The buffer routine traverses each of the input feature's
vertices and creates buffer offsets. Output buffer
features are created from those offsets.
Multiple Ring Buffer
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Feature
Overlay
Buffer Distance
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Feature Overlay
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Feature Overlay
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Feature Overlay
Feature Overlay
Union
Computes a geometric
intersection of the Input Features.
All features will be written to the
Output Feature Class with the
attributes from the Input
Features, which it overlaps.
Intersect
Computes a geometric
intersection of the input
features. Features or portions of
features which overlap in all
layers and/or feature classes will
be written to the output feature
class.
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Spatial Adjustment
(Transformations)
Spatial Adjustment
Data are geometrically distorted or
rotated relative to the base data
Move or shift data within a coordinate system.
often used to convert data from unknown digitizer or
scanner units to real-world coordinates.
can also be used to convert units within a coordinate
system, such as converting feet to meters.
Functions are based on the comparison of the
may be introduced by imperfect
registration in map compilation,
lack of geodetic control in source
data, or a variety of other causes
Spatial adjustment tools provide
interactive methods to align and
integrate your data
coordinates of source and destination points, also
called control points, in special graphic elements
called displacement links
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Spatial Adjustment (Rubbersheeting)
Spatial Adjustment
(Edge Match)
Aligns features along the edge of one layer to features
of an adjoining layer.
Mainly used when you want to merge separate
adjacent layers, such as soils or contours sheets
The layer with the less accurate features is typically
adjusted, while the adjoining layer is used as the
control.
Displacement links are used to adjust vertices or the
ends of line features to the corresponding locations in
the adjoining control layer.
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Point Statistics
Line Statistics
calculates statistics on point features that fall in the
Calculates a statistic on the attributes of lines in a
neighborhood around each output raster cell
operates directly on the point features instead of on a
raster
Adv.: points are not lost in converting to a raster if they
are too close together
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circular neighborhood around each output cell
Mean, Majority, Maximum, Median, Minimum,
Minority, Range, Std (standard deviation), and Variety
Majority, minority, and median statistics are weighted
according to the length of the line
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3D Visibility Analysis
Some questions GIS can answer
What is the quickest way to get from point A to point B?
Which houses are within five minutes of a fire station?
What market areas does a business cover?
A person wants to visit a store. Which branch should the
potential customer visit to minimize travel time?
Which ambulances or patrol cars can respond quickest to an
incident?
How can a fleet of delivery or service vehicles improve customer
service and minimize transportation costs?
Where can a business open a store to maximize market share?
If a company has to downsize, which stores should it close to
maintain the most overall demand?
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Network Analysis
Shortest Path
Service Areas
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