Feature Description

This tool is used to calculate the surface volume of a raster dataset, which represents the spatial volume between the 3D surface fitted by the raster dataset and a reference plane within a selected polygonal area.

To calculate surface volume, you must specify the base elevation - the elevation value serving as the reference horizontal plane for volume measurement. As shown in the figure below: When the base elevation is set to 50 meters, the calculated volume includes regions A, B, and C between the reference plane and raster surface. When the base elevation is set to 100 meters, only the volume of region A is calculated.

Figure: Surface Volume with Different Base Elevations

Steps

Surface Volume

1. Open the raster dataset for surface volume calculation in the map. Note: This function is unavailable if no raster data is open in the current workspace.
2. Navigate to Spatial Analysis Tab -> Raster Analysis -> Surface Analysis -> "Surface Volume". The output window will prompt: "Draw a polygon on the map, then right-click to analyze."
3. Draw a polygon on the map and right-click to open the "Surface Volume Parameter Settings" dialog. Input the base elevation. The default value is the minimum elevation of the specified area. If the input exceeds the maximum elevation of the analysis area, the application will provide an out-of-range notification and the valid value range.
4. Click "Calculate" to compute the volume under the temporary polygon. The output window will display the specified base elevation and calculated volume (default unit: cubic meters). Press Esc to clear temporary polygons.

Volume Calculation with Selected Polygons

1. Navigate to Spatial Analysis Tab -> Raster Analysis -> Surface Analysis -> "Selected Polygon Volume". The map will prompt: "Select one or more polygon features for surface measurement, right-click to finish selection."

   Alternatively: First select polygon features in the map (hold Shift for multiple selection), then click "Selected Polygon Volume" to directly open the parameter dialog.

2. In the "Surface Volume Parameter Settings" dialog, specify the base elevation. The default is the minimum elevation of the selected area. Input validation ensures values stay within the elevation range.
3. Click "Calculate" to compute the volume. Results display in the output window with cubic meters as the default unit.