Linear Referencing

Attribute information located along linear features, such as roads, streams and pipelines, are most of the times mis-represented or not represented at all. More often than not, most linear features would have additional set of attributes existing within them and proper interpretation of these additional attributes is also important.

Linear referencing makes it less complicated to represent attributes along linear features. This makes it possible to have several sets of attributes information that accompanies a single linear feature. Linear referencing shares geographic information without the explicit X-Y coordinate system. Instead it measures distances along a linear feature.

Exercise Procedure;

For this exercise, the linear feature I worked with was road. The road route had points showing where accidents had occurred and also had pavement events which showed the ratings for road conditions. Both the accident route and pavement routes were combined/ intersected in ArcMap. This was done to determine if the actual road conditions had any effect on accidents. Road conditions were rated from 1-100, and points where road accidents occurred were compared between pavements that had ratings of less than 75 and greater than 75.

A sample of my workflow process is shown below;

Adding route event (accident); click to enlarge

Intersecting events (accidents and road route), click to enlarge.

Application and Reflection;

Additional information can be retrieved from different linear features such as roads, pipelines and streams. This information can be a point or linear location within a single linear route. For example the particular point on a stream route that has the highest number of a particular fish species can be identified on a stream linear feature. I can also determine if there are particular water nutrients or if the water quality along the stream feature is responsible for having more concentration of fish species at a particular point of the stream. This can be used for different kinds of analysis and results can be mapped for easier understanding. Back to Top