Intro to Overlay Analysis

Question 1

What are the 7 steps of the spatial analysis approach?

Answer 1

Ask questions
Explore and prepare data
Analyze and model
Interpret results
Repeat or modify
Present results
Make decisions

Question 2

What are the 5 overlay analysis methods?

Answer 2

Erase
Identity
Intersect
Spatial join
Union

Question 3

This overlay analysis method creates a feature class by overlaying the input features with the polygons of this feature. Only features outside of the target area are then copied.

Removes parts of the first map that overlap with the second, leaving you with only the non-overlapping parts.

Answer 3

Erase

Question 4

This overlay analysis method computes a geometric intersection of the input features and this feature. Pieces that overlap these features get the attributes of these features.

This is like layering two maps on top of each other and combining the information where they overlap. When using this tool, it keeps the shape of the first layer, but adds information from the second layer where they overlap. The new layer shows both areas together, including where they intersect.

Shows both non-overlapping and overlapping parts.

Answer 4

Identity

Question 5

This overlay analysis method computes a geometric ____ of the input features. Pieces that overlap in all layers and/or feature classes are written to the output feature class.

This tool finds the common ground between two or more layers. Think of it like a Venn diagram - only the areas where the layers overlap are kept. This will create a new map that only shows the places where both layers exist at the same time.

Shows only the overlapping parts.

Answer 5

Intersection

Question 6

This overlay analysis method connects two layers based on their location. It’s like pairing up things that are near each other on a map. It adds information from one layer to another based on where they are in space, helping you see how different map features are related by location.

Target features and joined attributes are written to the output feature class.

Answer 6

Spatial Join

Question 7

This overlay analysis method combines two or more layers to create a new layer that contains all areas from all the input layers. It’s like stacking two maps on top of each other and keeping everything from both maps, including where they overlap and where they don’t.

Answer 7

Union

Question 8

This refers to attribute fields and values being added to the end of the input data. When on feature intersects a target feature. The tools that do this include County Overlapping Features and Spatial Join.

Answer 8

Append

Question 9

This is when more than one features is matched to a target feature. The rules combine values into a single output value. The rules include First, Last, Join, Sum, Mean, Min, and Max. The tool that does this is Spatial Join.

Answer 9

Merge

Question 10

This is when a feature is split using an overlay analysis method. It’s a way of comparing two sets of numbers in your data to see how they relate to each other. It’s like dividing one number by another to find out their proportion or relationship. Tools that do this include Erase, Identity, Intersect, Symmetric Difference, Union, and Update.

Answer 10

Ratio of Numeric