Elevation Difference
Computes cell-wise change in elevation.
Δz = zafter − zbefore
DEM Cut & Fill Analysis
Compare two elevation surfaces to estimate areas and volumes of excavation (cut) and embankment (fill).
Terrain / ElevationEnd-User DocumentationTheory + Formula + Parameters1. What This Feature Does
Compare two elevation surfaces to estimate areas and volumes of excavation (cut) and embankment (fill).
Cloud workflow: choose data → configure the scientific method → run → review the resulting layer/report. No programming is required.
2. Recommended Workflow
Choose Before and After DEMs.
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Align grids and vertical datum.
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Choose bands/nodata handling.
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Calculate elevation difference and volume.
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Review cut/fill totals.
3. Theory, Methods & Equations
Volume Integration
Multiplies height difference by pixel area and sums positive/negative contributions.
V = Σ ΔziAcell
Vfill=Σmax(Δz,0)A, Vcut=Σmax(−Δz,0)A
4. Input Data
| Input | Type | Requirement | Description |
|---|---|---|---|
| Reference / Before DEM | raster | Required | |
| Current / After DEM | raster | Required |
5. Parameters Available in the Application
| Parameter | Default | Choices / Range | How to Use It |
|---|---|---|---|
| Before DEM Band | — | — | |
| After DEM Band | — | — | |
| Minimum Height Difference (m) | 0.1 | 0 to — | |
| DEM Alignment Resampling | bilinear | nearest, bilinear, cubic |
6. Output & Interpretation
The result should be interpreted according to the selected method and the physical meaning of the input data. Preserve source units, coordinate reference information, NoData meaning, acquisition date, and preprocessing level when comparing results.
Scientific interpretation: an algorithm can produce a numerically valid result even when the input data are unsuitable. Always check masks, units, sensor characteristics, spatial resolution and reference data.
Important: Both DEMs must use compatible horizontal grids, vertical units and vertical datums before volume is interpreted.
7. Best Practices
- Use analysis-ready inputs and remove invalid/cloud/noise artifacts that are not part of the target phenomenon.
- Choose parameters from the physical scale of the data, not only from visual appearance.
- Keep categorical and continuous rasters conceptually separate when selecting interpolation/resampling methods.
- Compare the result with the source image and independent reference information.
- Document the settings used when results will be compared across dates, sensors or study areas.