Description

The attached template file shows how to use the StreamOrderCalculator to assign Strahler order numbers to streams in a river network. 

The source data is available from our FMEData training dataset. The hydrology data is a set of linework as below





Using a Digital Elevation model of the area of interest allows us to determine the direction of flow of the streams.



The resulting output showing Stream Order numbers looks like 



One remaining issue is that if the stream segment is relatively flat so that the elevation of each end of the stream is the same then the workspace may not correctly identify the low point of the stream. This happens to the small network in the upper left hand corner of this image. Two low points (nodes) are passed into the StreamOrderCalculator and it can only make use of one of them. It may not be the correct one so additional logic may be required to resolve this issue.