GIS15

Temporal Analysis
A temporal GIS extends common GIS operations to document time effectively.
– Why isn’t time already a fundamental part of GIS?
• For historical reasons, GIS has focused on spatial analysis as static in time.
Spatiotemporal data sets are not as common as spatial data.
Some examples…
 
• In a temporal GIS, either the snapshot or lifeline approach needs to track change.
 
– Several types of changes can occur as a function of time.
• Most important changes are creation and destruction.
• Objects can also disappear and reappear from a scene.
– Transformation and transmission:
• Transformations are independent changes to an object.
• Transmissions are dependent on other surrounding objects.
• Both include:
– Changes in location (spatial).
– Changes in attributes (aspatial).
• Temporal GIS is now aided by improved visualization through animations.
 
• While animations are useful, we really want to exploit temporal analyses in GIS.