Topology

Question 1

What problem inspired the development of topology?

Answer 1

Seven Bridges Puzzle

Question 2

What is topology in a GIS?

Answer 2

A way to model spatial relationships to show how features share coincident geometry.

Question 3

What is ArcGIS topology?

Answer 3

A set of rules used to manage spatial integrity of features.

Question 4

Who developed concepts of topology?

Answer 4

Leonhard Euhler

Question 5

What does topology rules do in a GDB?

Answer 5

Define and constrain how features hare coincident geometry.

Question 6

What are topological primitives?

Answer 6

Nodes, edges, faces are fundamental entities with spatial relationships represented in a topology

Question 7

Describe 4 main spatial relationships that topology can check:

Answer 7

adjacency, connectedness, containment, proximity

Question 8

Two reasons why topology is important:

Answer 8

1) understand how locations relate to one another 2) manage data integrity

Question 9

What are slivers?

Answer 9

small gaps or overlaps that can be created during GP operations.

Question 10

What are the two types of topology?

Answer 10

Map topology and GDB topology

Question 11

Where is map topology stored?

Answer 11

In an AGP project file.

Question 12

Where is GDB topology stored?

Answer 12

In a FDS.

Question 13

Does shapefile data format support GDB topology rules?

Answer 13

No.

Question 14

Can shapefiles be managed using map topology?

Answer 14

Yes.

Question 15

Know similarities and differences between Map and GDB topology:

Answer 15

• Map topology works with all levels of ArcGIS software, & works with shapefiles and FCs, don’t have to be in a
  FDS, but only allows coincident features to be moved or edited & no topology rules, no validation is supported.
• GDB topology stores rules, topology errors and exceptions as features. Rules define how features can interact and
  can be validated to determine if any errors are present.

Question 16

Where should all FC reside in a GDB topology?

Answer 16

In a FDS.

Question 17

Can a FDS store multiple topologies?

Answer 17

Yes. But a FC can participate in only one GDB topology at a time.

Question 18

Why is a GDB topology added to a map?

Answer 18

To view errors.

Question 19

What are errors called when they persist in a topology?

Answer 19

Exceptions

Question 20

What is a vertex?

Answer 20

Is located along an edge, defines the shape of line and polygon features, and can be edited.

Question 21

What is XY cluster tolerance?

Answer 21

Distance range where all vertices are considered identical. When topology is validated,
the cluster tolerance is used to move coordinates of lower accuracy (if ranked) to locations of more accurate coordinates
within that tolerance.

Question 22

How does ranks work in a topology?

Answer 22

If a FC is assigned a high rank (ex .1) the less the feature will
move during validation if two or more vertices fall within the cluster tolerance. If a FC is assigned a low rank (ex. 5) then
features within the cluster tolerance will move instead of a higher ranked feature.