WMS:Coverages

Feature objects in the Map module are grouped into coverages. A coverage is similar to a layer or level in a CAD drawing, or a theme or layer in ArcView®. Each coverage represents a particular set of information. For example, one coverage could be used to define drainage boundaries and another coverage could be used to define land use or soil zones. These objects could not be included in a single coverage since polygons within a coverage are not allowed to overlap.

Coverages are managed using the Project Explorer. Coverages can be organized into folders and moved once they are created. When WMS is first launched the default coverage is a drainage coverage. When multiple coverages are created, one coverage is designated the "active" coverage. New feature objects are always added to the active coverage and only objects in the active coverage can be edited. The figure below shows several coverages in the Project Explorer. The active coverage is displayed with a color icon and bold text. A coverage is made the active coverage by selecting it from the Project Explorer. In some cases it is useful to hide some or all of the coverages. The visibility of a coverage is controlled using the check box next to the coverage in the Project Explorer.

A new coverage can be created by right-clicking on a folder and selecting the New Coverage command in the pop-up menu.

Right clicking on a coverage bring up a menu with the following options: Delete, Duplicate, Rename, and Properties. The Delete, Duplicate, Rename, Properties, and Coordinate Conversion commands are self explanatory.

The Properties command brings up the Coverage Properties dialog. The coverage properties dialog allows you to specify what the coverage type is, its default elevation (mostly used for displaying and overlaying) and change the name (although the name of the coverage can also be changed from the Project Explorer in the same fashion as changing a name in a typical Windows Explorer.

Coverage Types

Each coverage is assigned a coverage type that controls which set of attributes are associated with the coverage. The appropriate type for a coverage depends on the intended use of the coverage. The available types are as follows:

• 1D-HYD Centerline
• 1D-HYD Cross-section
• Area Property
• CE-QUAL-W2 Branch
• CE-QUAL-W2 Observations
• CE-QUAL-W2 Segments
• Drainage
• Flood Barrier
• Flood Extent
• General
• Land Use
• MODRAT DPA Zone
• MODRAT Tc
• NFF Region
• Observation
• Rain Gage
• Rainfall Zone
• Runoff Coefficient
• Soil
• Storm Drain
• Time Computation

Related Topics

• Feature Objects