Understanding GIS Integration and Skeletonization

In InfoWater Pro, hydraulic modelers can choose between models which incorporate one-to-one GIS integration, and those which are skeletonized representations of the distribution system. There are advantages and disadvantages to both methods.

GIS Integration Advantages:

As GIS capabilities have evolved, so too has the ability for InfoWater Pro to directly utilize GIS data for model construction and calibration.

Main advantage of GIS integration is ability to maintain one-to-one relationship between model and GIS, utilizing factors such as:

• Element naming conventions
• Geometric layout
• Geographic positioning

Allows for more accurate communication among modeling staff, GIS staff, and field maintenance staff when identifying particular system elements in need of repair or replacement.

Improves water quality modeling, surge analysis, fire flow analysis, and unidirectional flushing analysis, or UDF.

GIS Integration Disadvantages:

Models can be very large, particularly when constructed and maintained in “all-pipes” environment.

Depending on size and complexity of distribution system, models can have large data and output file sizes, resulting in longer opening, simulation and file save times.

Conscientious maintenance of GIS can ensure that polyline segments are split appropriately.

This ensures accuracy of pipe interconnectedness when creating or updating model from GIS.

Skeletonization Advantages:

Skeletonization is the process of reducing the size of the model to its most applicable features, without sacrificing the overall hydraulic equivalency of an “all-pipes” model.

Typically constructed using portion of GIS of entire distribution system.

Simpler, run faster, and have reduced file sizes.

Skeletonization Disadvantages:

Not ideal for water quality modeling—for example, analyzing constituent decay in remote portions of system would yield inaccurate results if those portions were omitted from skeletonized model.

Can reduce accuracy of surge and fire flow analyses, due to omitting potentially significant elements.

SCADA monitoring points and calibration locations may not always remain in skeletonized model.