Calculating the Volume of a Lake

To illustrate the capability of using the Grids | Calculate | Volume command, consider the application of calculating the volume of water within a lake. This application requires that a grid file be created which defines the lake bottom. The other surface is defined as a horizontal planar surface that defines the water surface of the lake.

To calculate the volume of a lake:

  1. Create the grid file for the lake. If the lake bottom is defined as the depth of the water, use negative Z values so that the lake appears as a basin rather than a hill. It is also recommended that data points be added beyond the limits of the lake shore so that the surface is above the level of the lake in those areas.

  2. Select the Grids | Calculate | Volume command.

  3. Specify the grid file for the lake in the Open Grid dialog and click Open .

  4. In the Grid Volume dialog, click the Grid File option in the Lower Surface group.

  5. In the Upper Surface group, click the Constant option. Enter the value for the lake surface into the Z = box. For example, if you are using depth in your grid file as a negative value, the Z = value for your horizontal (lake) surface should be zero.

  6. Click OK and the volume and area calculations are reported. The volume of the lake is reported as the Positive Volume.

  7. To save the information, use the File | Save As command in the Grid Volume Report window and specify a name and file extension.

See Also

Calculating the Volume of a Grid with NoData Values

Calculating the Volume between Two Surfaces