GTECH 201

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GTECH 201

• Lecture 05Storing Spatial Data

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Leftovers from Last Session

• From data models to data structures
• Chrismans spheres
• ANSI Sparc
• The role of GIScience
• Maps as models
• Intro to GIS (the ArcGIS way)

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Chrismans Spheres
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ANSI-SPARC Model for Software Development
GIS are systems to model the world User Model
Conceptual Model
Operational

Model
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GIS are Systems to Model the World
User Model how we intuitively think
Conceptual Model
Operational

Model ANSI-SPARC Model for software
development
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GIS are Systems to Model the World
User Model Conceptual
Model
Operational
Model ANSI-SPARC Model
for software development
how we systematically define ideas
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GIS are Systems to Model the World
User Model Conceptual
Model
Operational
Model
how we fuse systematic thinking into a
technologically defined context
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The ANSI/SPARC Model and Chrismans Spheres
application disciplines
geoinformation theory
computer science
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Digital Maps as Models
Representing a complex reality Continuous
variation Spatial Data spatial, temporal and
thematic Data Models
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What sort of Models are These?

• Raster Model - The world as regular tessellations
  defined by areal property
• Vector Model - The world as points, lines, areas
  and attributes.. making objects
• Object Model - The world as interacting entities
  with spatial dimensions

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Vector Data Models

• Spaghetti model
• Topological models

A file of spatial data that is a just a
collection of co-ordinate strings. Each entity
(or piece of spaghetti) is represented by one
data entry. There is no topology.
Topology refers to the spatial relationships
between objects. The topological model
represents spatial relationships such as -
length - area - connectivity - contiguity
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Further Reading
ANSI/SPARC model Laurini Thompson. Fundamentals
of GIS, p.357-362 Chrismans Spheres Chrisman, N.
1997. Exploring Geographic Information
Systems Key Text for Concepts De Mers, M. 2004.
Fundamentals of Geographic Information
Systems. NY John Wiley Sons
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GIS Map Organization
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Representation

• Point, line, and polygon features

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Geo-Relational Principle 1
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Geo-Relational Principle 2
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System Architecture
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ArcMap
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Map Production
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ArcCatalog
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ArcCatalog Views
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ArcToolbox
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Metadata
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Metadata in ArcGIS
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Help
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Maneuvering ArcGIS
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Connecting to Folders
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Table of Contents
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Exploring a Map
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MakingAppearances
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Making
Appearances
part 2
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Localized Information
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Spatial Relationships 1

• Distance

Which countries contain a lake completely within
their borders? Which cities are located within 25
kilometers of a river?
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Spatial Relationships 2

• Intersection

Which countries have a river that intersects
their border?
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Spatial Relationships 3

• Adjacency

Which countries share a border with Russia?
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Spatial Relationships 4

• Containment

Which countries contain a lake completely within
their borders?
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GIS as a Process 1

1. Capture data
2. Store data
3. Query data
4. Analyze data
5. Display data
6. Present data

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GIS as a Process 2

1. Ask a geographic question
2. Acquire geographic data
3. Explore geographic data
4. Analyze geographic information
5. Act on geographic knowledge

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Summary

• A GIS organizes and stores information about the
  world as a collection of thematic layers. Each
  layer contains features with the same shape and
  attributes, all located within a common
  geographic area.
• Each feature is assigned a unique numerical
  identifier and is characterized by a unique
  location in space and a corresponding record in a
  table.
• Features can be stored in a GIS as three primary
  shapes points, lines, or polygons.
• Features have spatial relationships with other
  features, and with a GIS you can find features
  based on their spatial relationships.
• The geographic inquiry process provides a
  framework for solving problems with GIS.