GIS Lecture: Selection

Outline Attribute Selection Feature Location Selection Proximity Selection

Attribute Selection

Attribute Query Selection You have tracts for an entire state, but want tracts for one county only

Attribute Query Selection Select tracts by County FIPS ID Cook County = 031

Export Selected Features Right-click to export selected features

Add Exported Layer Cook County tracts

Feature Location Selection

Select by location Powerful function unique to GIS Identify spatial relationships between layers Finds features that are within another layer

Select by location Have Cook County census tracts but want City of Chicago only Can’t use Select By Attributes No attribute for Chicago Use “Municipality” layer City of Chicago is a municipality within Cook County

Select by location Select “Chicago” from municipalities layer

Select by location Selection, select by location

Export selected features

Proximity Selection

Points near polygons Health officials want to know polluting companies near water features

Points near points School officials want to know what schools are near polluting companies

Polygons intersecting lines Transportation planner wants to know what neighborhoods are affected by construction project on major highway

Lines intersecting polygons Public works official wants to know what streets or sidewalks will be affected by potential floods

Polygons completely within polygons City planners want to know what buildings are completely within a zoning area.

Other Location Selections Completely contain Are completely within Share a line segment with Touch the boundary of Are identical to Are crossed by the outline of Are within

Summary Attribute Selection Feature Location Selection Proximity Selection