(The Volumes module is required for this procedure.)
This procedure is used to compute a volume between any two terrain models. You may obtain additional help by clicking the underlined topics. If you do select an underlined topic, you may return to this procedure by clicking the Back key.
- Ensure that the required data base is open.
Refer to the procedure for opening a data base.
The data base that you open should contain the finished surface or the design surface that is to be achieved. - Ensure that the required terrain model of the finished or design surface has been successfully
formed.
Refer to the procedure for Forming a Digital Terrain Model. - Select the Volumes task.
- Select the Volume/Surface to Surface command and use the
Surface to Surface Volumes dialog box to:
- Select the region size to be used.
- Select the primary model number. This is a model in the currently open dataset representing the finished or design surface. It is the model formed in step 2.
- Select the secondary dataset and model number. This may be any model other than the primary model. It may be a model in the currently open dataset or a model in some other dataset selected via the Select button. Refer to the Select Secondary Data Set dialog box. The secondary model represents a surface that has or will be cut or filled to achieve the primary surface. It must have been formed prior to commencing this procedure.
- Select the code table to be used for the creation of new points and lines to define the:
- -no cut/no fill lines (i.e.. where the surfaces intersect)
- -common boundary lines (i.e.. the extent of the area common to both surfaces)
- -a new height difference data set.
- Use the check boxes in the Common Data group to select whether the surface intersections, common
boundary, and/or height difference data set are to be created. If selected for creation, use the
appropriate Define button to select the codes to be used. Refer to the following dialog boxes:
- No Cut / No Fill Codes dialog box
- Boundary line Codes dialog box
- Create Height Difference Database dialog box.
- Select whether the output of the volume results is to be to screen, printer or file.
- Select the Compute button to calculate and output the volume and create the new objects as specified in the Common Data group. Refer to the Surface to Surface Volume Results dialog box.
- If you generated a height difference data set, you may wish to open that database, model it, and display the contours to view a model of the cut and fill areas. Taking a volume to a plane of zero elevation will provide an independent quality control check on the volumes obtained from step 4. The results will of course not be exactly the same, as they are from a new model with a different triangle structure.