Lecture 7 Basic GIS Analysis Operations

Analysis of GIS data Identify Find Query – attribute Query – spatial Table operations  Join  Spatial join  Summarize and other statistics Symbology, classificaion in making a map

Identify

Spatial Select

Find

Labels Double-click

Labels - Population

Combine values with text with &

Label with multiple values "Population: " & [POP1990] & vbcrlf & "County: " & [NAME] & connects two text strings Vbcrlf – visual basic carriage return line feed (next line) Fields [ ] Strings “ “

Attribute query

Spatial query Use points, lines, and polygons to select other points, lines, and polygons. Use a relationship  Intersecting  Inside  Neighbors  Within a distance of

Spatial query -Intersect Layer 1 Relationship Layer 2 Result

Spatial query - Intersect result Counties that interstate 5 crosses

Spatial query - Contains Cities inside San Diego county

Spatial query - Near Cities within 2 miles of Interstate 5

Spatial query - Near Cities within 1 mile of Interstate 5 Just those cities, in their own shapefile How’d they do that?

Analyze result – Export to shapefile

Analyze result – New shapefile

Analyze result – Create a report

Report properties – fields and order

Report

Create a chart

Chart wizard

Chart

Table operations - Join Common field (primary and foreign key) One to one relationship (one county has one census record) Fields from one table are appended to the other table Bring spatial and attribute data together

Table operations - Join Matching records merge into the one attribute table

Table operations – Spatial Join Common location One to Many Relationship (One county has hundreds of quakes) Fields from one table are appended to the other table Bring spatial and spatial data together

Spatial Join tables Common location

One spatially joined table Matching records merge into the one attribute table

Summarize a field How many quakes per county?

Build a statistics/summary table

Join summary table and county table

Symbolize – Quakes per county

Normalize by area – Quakes per square mile

Normalize by area – Quakes per person