Table of Contents
Exploring Geographic Information Systems
Second Edition
by Nicholas R. Chrisman
Preface
Call for participation in an exploration
Part 1: Building Blocks of Geographic Information
Introduction
- Explore a GIS in operation.
- Define a geographic information system in its historical
context.
Chapter 1: Measurement Basics
- Introduce reference systems for time, space and attributes.
- Extend Steven's levels of measurement to provide a richer
basis for attribute measurement.
How Information Works
Basic Components of Geographic Information
Reference Systems
Levels of Measurement
Nominal
Ordinal
Interval
Ratio
Extensive and derived scales
What is missing from Stevens
Applying Measurement Levels to Attribute Refeence Systems
Chapter 2: Measurement Frameworks
- Present a scheme to guide measurement of geographic phenomena.
- Provide examples of major measurement frameworks.
- Explain basic principles of two-dimensional topology.
A Simple Measurement Framework
Control and Measurement
Attribute as Control: Isolated Objects to Connected Coverages
Isolated Object Framework
Spatial object framework
Isoline framework
Connected coverage frameworks and Topological relationships
Network framework
Categorical coverage framework
Spatial Control
Point-based frameworks
Center point framework
Area-based measurement frameworks
Extreme value
Total
Predominant type
Presence/ absence and percent cover
Precedence of types
Relationship Control
Measurement by pair
Triangulated Irregular Networks (TIN)
Composite Frameworks
Scattered point samples
Associating Attributes - Indirect Measurement
Choropleth maps (collection zones)
Temporal Frameworks
Chapter 3: Representation
- Introduce the primitives used to represent spatial and
attribute measurements.
- Describe basic data structures: vector and raster.
- Follow steps that convert existing documents into digital
databases.
- Introduce components of data quality evaluation applied
to digitizing
Primitives for Representation
Primitives for Attributes
Primitives for Time
Primitives for Space: Coordinates
Representation Models and Data Structures
Vector model
Representing isolated objects
Topological data model
Raster model
Database Architecture
Conversion of Existing Documents (Digitizing)
Geocoding
Vector tracing
Raster scanners
Transforming Digitizer Measurements into Coordinates
Registration on device
Transformations from document to projection
Reference to geodetic surveys
After digitizing
Data Quality: closing the loop
Scale of sources
Verification and Quality Control
Part 2: Transformations and Operations
Chapter 4: Attribute-based Operations
- Present operations that modify attributes without involving
spatial component.
- Demonstrate interactions of spatial and attribute components
caused by attribute operations.
Manipulating Attributes
Reducing the information content
Increasing the information content
Combining Pairs of input values
Interaction of Attribute and Spatial Components
Spatial consequences of Aggregation and Isolation
Cartographic Generalization
Chapter 5: Overlay Integrates Disparate
Sources
- Review origins of map overlay analysis.
- Describe geometric operations that establish connections
between diverse sources.
- Present rules for combining attributes.
Development of Map Overlay
The Overlay Operation
Registration: a Universal Requirement
Raster Implementations of Overlay
Vector Implementations of Overlay
Geometric component
Attribute handling using results of overlay
Comparisons of Performance and Capabilities
Combining Attributes After Overlay
Enumeration Rules
Detecting differences
Interpreting differences
Dominance Rules
Exclusionary screening
Exclusionary ranking
Highest bid/ Higest bidder
Contributory Rules
Voting tabulation
Weighted voting
Linear Combination
Weighting and rating
Non-linear combinations
Interaction rules
Contingent weighting
Evaluating interactions
Rules of combination
Summary of rules
Chapter 6: Distance Transformations
- Construct vector buffers around isolated objects.
- Perform distance measurements and construct distance fields
for rasters.
- Introduce extended Voronoi representations of distance
relationships.
Examples of distance specifications
Exclusionary zones around features: Buffers and setbacks
Beyond buffers and setbacks
Distance measurement
Distance relationships
Constructing buffers with vector data
Measuring distance in a raster
Comparison
Extended Voronoi Diagrams
Data Quality Aspects of Distance Relationships
Chapter 7: Surfaces and Near Neighbors
- Describe properties of surfaces and how they are calculated.
- Review geometric component of neighborhood construction.
- Present rules for combining attributes discovered inside
a neighborhood.
Surfaces
Topology of surfaces
Computing relationships on a surface
Slope from triangles
Slope from matrices
Neighborhood Operations: The Spatial Component
Neighborhood construction
Raster neighbors
Vector neighbors
Edge effects
Refinements of neighborhoods
Combining Neighborhood Attributes
Nominal attributes
Dominance rules
Contributory rules
Interaction rules
Operations based on ranking attributes
Continuous attributes
Aspatial treatment of continuous attributes in a neighborhood
Continuous attributes with horizontal measures
Data Quality Applications of Neighborhood Operations
Chapter 8: Comprehensive Operations
- Develop iterative operations that use neighborhoods to
reach more distant goals.
- Demonstrate linkage between location-allocation methods
and GIS
- Link goals of statistical analysis and GIS
Iterative Operations
Viewshed
Cost Accumulation
An example of cost surface construction: A water pipeline
Drainage operations
Network operations
Location-Allocation Problems: A Family of Problems with a
Common Approach
Statistical Modeling of Spatial Data
Chapter 9: Transformations
- Review prior approaches to transformations in analytical
cartography.
- Describe operations to transform surface information between
measurement frameworks.
- Develop taxonomy for transformations: neighborhood and
attribute assumptions.
Prior Approaches to Transformations
Transformations for Surfaces
Interpolation
Interpolation from scattered points
Interpolation from isolines
Interpolation from a DEM
To and From Triangles
Network Information and Surfaces
A Scheme for Transformations
Transformation by Extraction (Case 0)
Transformations based on Attribute Assumptions (Case 1A)
Transformations based on Geometric Processing Only (Case
1N)
Complete transformations (Case 2)
Examples of Transformations
Case 1A: Classification of remotely sensed imagery
Forest Mapping for the United States
Case 1N: Geometric Measures Converted to Attributes
Wetland Regulation and Wasteland Assessment in Westport,
Wisconsin
Case 2: Areal interpolation
Dasymetric Mapping of Population Density, Cape Cod
Part 3: The Broader Arena
Chapter 10: Evaluation and Implementation
- Review measures used to evaluate geographic information
systems.
- Describe procedures to implement a new GIS.
Technical Evaluation
Data Quality Assessment
Allocation of Resources
Computer Resources
Financial Resources
Human Resources
Implementing a GIS
Needs assessment
Requirements analysis
Construction
Serving Larger Goals
Chapter 11: Social and Institutional
Context
- Place geographic information in historical and cultural
context.
- Sketch the geography of geographic information worldwide.
- Consider institutional, social, and cultural consequences
of GIS.
Historical Trends in Technological Change
Geography of Geographic Information
Geographic Information in the Bureaucracy
Information in its Social Context
Equity
Access to Information
Balancing competing concerns
Information and Culture
Culture: Continuity and Change
The Practice of GIS
Bibliography
Sources and Credits
Index
Version of 19 September 2001