1. Lecture 4: Intro to the Vector Data Model and to Map Layout
Lecture 3b
Introduction to GIS
Lecture 4: Intro to the Vector Data Model and to Map Layout
By Weiqi Zhou, University of Vermont
Thanks are due to Prof. Troy, upon whose lecture much of this material is based.

2. Lecture 3b
Introduction to GIS
1. Vector Data Model

3. Introduction to GIS
Intro to Vector
Three basic “feature” or “object” types in the vector data type:
Point
Arc
Polygon
A given layer holds a given feature type

4. Point layer A point layer: a bunch of (x,y) coordiantes
Introduction to GIS
Point layer
A point layer: a bunch of (x,y) coordiantes
Image source: ESRI Arc Info electronic help

5. Line (Arc) layer Points define lines (arcs)
Introduction to GIS
Line (Arc) layer
Points define lines (arcs)
Feature is the ARC, not the line segments
Line segments
Verticies
Arcs meet at the nodes
Node
Image source: ESRI Arc Info electronic help

6. Introduction to GIS
Line (Arc) layer
Each point has a unique location

7. Polygon layer In a polygon layer, lines (arcs) define areas
Introduction to GIS
Polygon layer
In a polygon layer, lines (arcs) define areas
Lines (Arcs)
Points
Closed region
Boundaries: line segments
Area of homogenous phenomena

8. Polygons VS Rings Which one is polygon? Polygon Ring
Introduction to GIS
Polygons VS Rings
Which one is polygon?
Polygon
Ring

9. Introduction to GIS
Vector: Topology
Definition1: Explicit encoding of spatial relationships between objects: the spatial location of each point, line and polygon is defined in relation to each other
Definition2: Topology is a collection of rules and relationships that enables the geodatabase to more accurately model geometric relationships found in the world.

10. Vector: Topology Defines spatial relationships Rules & relationships
Introduction to GIS
Vector: Topology
Defines spatial relationships
Rules & relationships
Model geometric relationships

11. Why Topology Two major purposes Allows for powerful analysis tools
Introduction to GIS
Why Topology
Two major purposes
Allows for powerful analysis tools
Quality control mechanism

12. Types of Vector Topology
Introduction to GIS
Types of Vector Topology
Arc-node topology
Polygon topology
Route topology
Region topology

13. Arc-node & Node Topology
Introduction to GIS
Arc-node & Node Topology
Connectivity analysis
Arc-node Topology
Arc-node List
Direction
Image source: ESRI Arc Info electronic help

15. Polygon-arc Topology The order does matter! Polygon-arc Topology
Introduction to GIS
Polygon-arc Topology
Polygon-arc Topology
Polygon-arc List
The order does matter!
Image source: ESRI Arc Info electronic help

16. Polygon-arc Topology Adjacency External polygon Introduction to GIS
Image source: ESRI Arc Info electronic help

17. Route Topology Define paths base on arcs Introduction to GIS
Image source: ESRI Arc Info electronic help

18. Regions Topology Regions: A list of polygons Introduction to GIS
Image source: ESRI Arc Info electronic help

19. Regions Topology Designed for complex analyses
Introduction to GIS
Regions Topology
Designed for complex analyses
Example: a region of forest fire damage (multi-temporal)
Image source: ESRI Arc Info electronic help

20. Example: State of Hawaii (a region) < -- > islands (polygons)
Introduction to GIS
Regions Topology
Designed for complex analyses
Example: State of Hawaii (a region) < -- > islands (polygons)
Image source: ESRI Arc Info electronic help

21. Quality control and topology
Introduction to GIS
Quality control and topology
Ensuring data quality and “logical consistency”
Define complex and nuanced spatial rules
Single layer quality control
Mutli-Layer quality control

22. Quality control and topology
Introduction to GIS
Quality control and topology
Single layer quality control
slivers
Undershoot
Dangles
overshoot
Not sharing border

23. Quality control and topology
Introduction to GIS
Quality control and topology
Mutli-Layer quality control: Defining spatial rules between layers
Polygon rules: e.g. Must Be Covered by Feature Class of
Line rules: e.g. Must not Self Intersect
Point rules: e.g. Must be Properly Inside Polygons
ArcCatalog includes new tools for defining and validating topology rules (Book: Building a geodatabase)

24. Topology rules: Example
Introduction to GIS
Topology rules: Example
Say we have the following layers: property lots, sidewalk, building footprints, zoning map
We can specify topological rules, like:
Lots must be enclosed polygons
Buildings must be entirely within a lot
Sidewalks must be outside a lot polygon and entirely within the public right of way
Lots must fall entirely within a single zone
All lots must have access to a right of way

25. Lecture 3b Non-topological data model
Introduction to GIS
Spaghetti Data Model
Non-topological data model
Collections of line segments and points
Only stores features coordinates
No real connection, topology or relationships
Not for spatial analysis
Generally come from CAD files or digitizing
Can “clean” these data, using user-defined tolerances

26. 2. Map Layouts and Cartographic Representation
Lecture 3b
Introduction to GIS
2. Map Layouts and Cartographic Representation

27. Lecture 3b
Introduction to GIS
Map Compilation X
Map?
Map Elements?

28. Map Compilation Title Legend Neatline Data frame North arrow Scale bar
Lecture 3b
Introduction to GIS
Map Compilation
Title
Legend
Neatline
Data frame
North arrow
Scale bar
Notes

29. Lecture 3b
Introduction to GIS
Layouts
Create a map for layout in ArcMap Layout view View>>Layout view.

30. Map Compilation Legend Geographic features Other map elements Title
Lecture 3b
Introduction to GIS
Map Compilation
Geographic features
Other map elements
Legend
Title
North arrow
Scale bar
Author
Neatline
Source of data
Other objects…

31. Lecture 3b
Introduction to GIS
Layouts
Legends are edited in the Legends property window: Accessed by double clicking the legends.
Give a title, e.g. land use
Symbol editing

32. Layouts Legends editing: Items Item Style Symbol Introduction to GIS
Lecture 3b
Introduction to GIS
Layouts
Legends editing: Items
Item
Style
Symbol

33. Lecture 3b
Introduction to GIS
Layouts
Legends editing: Frame
Frame

34. Layouts Legends editing: Size and position Size&Position
Lecture 3b
Introduction to GIS
Layouts
Legends editing: Size and position
Size&Position

35. ArcMap: data frame More than one frames can be shown in layout view
Introduction to GIS
ArcMap: data frame
More than one frames can be shown in layout view
Frame 1
Frame 2

36. Layouts: data frame Create a new view or “data frame” in ArcMap
Introduction to GIS
Layouts: data frame
Create a new view or “data frame” in ArcMap

37. Layouts: data frame Access and edit data frame properties
Introduction to GIS
Layouts: data frame
Access and edit data frame properties

38. MXD Files Mxd files are project files Save your layout
Lecture 3b
Introduction to GIS
MXD Files
Mxd files are project files
Save your layout
All other preferences
Data is not included
With an extension .mxd
To save: File>>save (As)

39. Layer Files Save symbology and setting
Lecture 3b
Introduction to GIS
Layer Files
Save symbology and setting
Primarily for saving legend setting
Opening a layer file will open the data layer with all the preferences saved
With an extension .lyr

40. Lecture 3b
Introduction to GIS
Layer Files
Use layer files when you have lots of non-numeric categories

41. Layer Files Create a layer file in ArcCatalog Introduction to GIS
Lecture 3b
Introduction to GIS
Layer Files
Create a layer file in ArcCatalog

42. Layer Files Create a layer file in ArcMap Introduction to GIS
Lecture 3b
Introduction to GIS
Layer Files
Create a layer file in ArcMap

43. Layer Files Import a layer file’s symbology in properties
Lecture 3b
Introduction to GIS
Layer Files
Import a layer file’s symbology in properties