WMS:2D Scatter Point Module

The Scatter Point module is used to interpolate from groups of scattered data points to grids or TINs. The Scatter Point module can be used to interpolate from a set of scattered xy points representing something like rain gauges to a finite difference grid or to basin centroids for establishing rainfall curves for HEC-1. A variety of interpolation schemes are supported.

Scattered data can be created using the Create Scatter Point tool. The most common use of scattered data is for creating water surface elevations to compute a floodplain delineation. Generally, in such cases, take advantage of a centerline and cross-sections to develop a larger dataset for floodplain delineation.

Scatter Point Sets

All the points from which values are interpolated are called scatter points. A group of scatter points is called a scatter point set. Each of the scatter points is defined by a set of XY coordinates.

Each scatter point set has a list of scalar datasets. Each dataset represents a set of values that can be interpolated to a grid or TIN. When an interpolation command is selected, the active dataset for the scatter point set is used in the interpolation process.

Multiple scatter point sets can exist at one time in memory. One of the scatter point sets is always designated as the "active" scatter point set. Interpolation is performed from the active scatter point set only. The active scatter point set can be changed using the Project Explorer. Whenever a new scatter point set is read from a file or created, it becomes the active set.

The most common uses of scatter point sets in WMS is for rainfall gages and the results of hydraulic modeling.

2D Scatter Point Tools

The toolbar for the 2D Scatter Point module.

The toolbar for the WMS 2D Scatter Point module has a variety of tools useful for editing and creating objects within that module. The tools are described below.

Select Scatter Point

The Select Scatter Point tool is used to select individual scatter points for displaying the coordinates and current function value of individual scatter points in the Edit Window.

Create Scatter Data Point

The Create Scatter Data Point tool is used to create new scatter points. The primary purpose of creating scatter points is to enter water surface elevations that can be used in a floodplain delineation. It can only be used in plan view.

Related Topics

• Interpolation
• Preparing Stages for Floodplain Delineation
• Interpolating Results Along a Centerline and Cross-sections
• Terrain Data Module