GTECH 201 Lecture 05 Storing Spatial Data

Leftovers from Last Session From data models to data structures Chrisman’s spheres ANSI Sparc The role of GIScience Maps as models Intro to GIS (the ArcGIS way)

Chrisman’s Spheres

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

GIS are Systems to Model the World User Model – how we intuitively think Conceptual Model Operational Model ANSI-SPARC Model for software development

User Model Conceptual Model Operational Model ANSI-SPARC Model for software development how we systematically define ideas GIS are Systems to Model the World

User Model Conceptual Model Operational Model how we fuse systematic thinking into a technologically defined context GIS are Systems to Model the World

The ANSI/SPARC Model and Chrisman’s Spheres computer science geoinformation theory application disciplines context discipline spatial modeling conceptual modeling logical data modeling physical data modeling OPERATIONAL

Digital Maps as Models Representing a complex reality Continuous variation Spatial Data: spatial, temporal and thematic Data Models

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

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

Further Reading ANSI/SPARC model Laurini & Thompson. Fundamentals of GIS, p Chrisman’s Spheres Chrisman, N Exploring Geographic Information Systems Key Text for Concepts De Mers, M Fundamentals of Geographic Information Systems. NY: John Wiley & Sons

GIS Map Organization

Representation Point, line, and polygon features

Geo-Relational Principle 1

Geo-Relational Principle 2

System Architecture

ArcMap

Map Production

ArcCatalog

ArcCatalog Views

ArcToolbox

Metadata

Metadata in ArcGIS

Help

Maneuvering ArcGIS

Connecting to Folders

Table of Contents

Exploring a Map

Making Appearances

Making Appearances part 2

Localized Information

Spatial Relationships 1 Distance Which countries contain a lake completely within their borders? Which cities are located within 25 kilometers of a river?

Spatial Relationships 2 Intersection Which countries have a river that intersects their border?

Spatial Relationships 3 Adjacency Which countries share a border with Russia?

Spatial Relationships 4 Containment Which countries contain a lake completely within their borders?

GIS as a Process 1 1.Capture data 2.Store data 3.Query data 4.Analyze data 5.Display data 6.Present data

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

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.