When building your Surface-water Modeling System (SMS) project, are you encountering issues because of poorly rendered or imported feature objects? When you have a large number of feature objects, it can be easy to have some drawn in the wrong location, overlapping other objects, or other errors. This can interfere with the operation of the simulation. Cleaning up the feature objects can make the difference in a successful running simulation and one that fails to converge.

When you create your surface water model, either by extracting features from existing data or building them manually, you can end up with multiple arcs and points that are unnecessary for your SMS model or may even interfere with the model’s simulation. By using the Clean Options dialog, you can consolidate or eliminate points, nodes, vertices, and arcs, all based on parameters you select.

The Clean Options dialog gives you multiple options. You can choose to clean every arc in a coverage, but perhaps you only want to focus on one set of arcs, one branch of a stream network for instance. The dialog will allow you to choose. You can run a full clean or select specific actions. You can control how close points, nodes, vertices, and arcs have to be before they are considered for snapping. You can also remove arcs that are less than a length you choose to enter.

The Clean Options dialog can be reached either through the Clean Options macro at the top of SMS, or through the Feature Objects | Clean… menu command. The algorithm used by the dialog applies clean operations to the active coverage in a priority order. Sometimes, snapping will create new cleaning opportunities and bumps the newly created opportunity to the top of the priority list. It will need to go through multiple iterations to check that all have been completed.

For instance, locations are sorted from left-to-right by their X-coordinates, with ties broken by sorting from bottom-to-top by their Y-coordinates. Segments are sorted by comparing their endpoints using the same comparison as for locations. Then the "first" locations on each segment are compared, and the segment containing the earlier location is chosen first. In the event of a tie, the "second" location is used to break the tie, and so on until all points, nodes, and arc segments have been cleaned. Once a location is moved, it is locked in place for the remainder of the iteration.

It is often wise to first duplicate the coverage you are trying to clean and rename it, before running the Clean Options dialog on the duplicate coverage. That way, if the parameters set were too high, you can go back to the original coverage, duplicate, and run it again with different parameters. If the clean didn’t change much, you can alter the selections and run it again.

The Clean Options function can save you a lot of time in fixing issues with your feature objects. Head on over to SMS, and see if the Clean Options function can help your project!