Temporal data is data that represents a state in time, such as the land-use patterns of Hong Kong in 1990, or total rainfall in Honolulu on July 1, 2009. This data comes from many sources, ranging from manual data entry to data collected using observational sensors or generated from simulation models. Below are some applications of temporal data in GIS.
- Visualize the locations of ocean mammals or other populations to understand patterns in their movement.
- Understand population increases per city or parcel boundary changes.
- Learn how fatalities from a disease are increasing based on changing colors in the layer symbology.
- View ocean temperature changes or weather patterns over time.
Store time values
Time values in your data can represent a point in time, sampled at a regular or irregular interval. These time values are stored in a single attribute field and can be used to visualize temporal data at particular times on the timeline. For example, stream flow data is collected at different points in time at regular intervals. However, lightning or earthquake data is collected at irregular intervals depending on when a particular lightning storm or earthquake occurs.
Time values can also represent durations of time, such as when a particular event occurs over a period of time. Time values in this case are stored in two fields, one representing the start time of the event, and the other representing the end time of the event. For example, polygon features representing a fire perimeter have a start and end time that depend on when the fire started and ended.
Use temporal data
Temporal data can be visualized with the time slider. The time slider provides controls to explore temporal data interactively and is available at the top of any map view that contains temporal layers.