A user defined chainage point is a specific location with a controlled chainage.
If a branch does not contain any user defined chainage points the start chainage is per default 0 and the end chainage equivalent to the length of the branch calculated based on the geographical length of the branch shape. Both the start and end chainage can be controlled by inserted user defined chainage points.
The chainage along a branch between two user defined chainage points are linearly calculated between the two defined chainage values. The chainage along a branch between a user defined chainage point and a branch end is calculated is calculated as the geographical distance from the defined chainage value.
User defined chainage points are added to the River network by using the ‘Add’ button in the ‘User defined chainage point’ section under the Branches ribbon in the Map view.
If user defined chainage points have been added in Map view their chainage may be edited under the User defined chainage points tab.
Note: If a user defined chainage point is moved the defined chainage is fixed and hence moving the point will update all chainages along the branch.
Example: A branch without user defined chainage values are created with a geographical length of 1000 m. The start chainage will be 0 and the end chainage will be 1000.
A user defined chainage point is added at 500 m (geographically) along the branch and given the chainage 750. The start chainage is now automatically updated to 250 and the end chainage to 1250.
Another user defined chainage point is added at 250 m (geographically) along the branch and given the chainage 100. The start chainage is now automatically updated to -150 and the end chainage is unchanged at 1250.
