Description
Calculate elevation drop to a supplied catchment outlet.
Geomorphic measurements distinguish signed coordinates, grain-size scales, profile derivatives and transported-mass or cross-section bases. A supplied datum adjustment or threshold does not detect a landform or establish a process. Plan distance, profile second derivative and slope-normalized curvature are different quantities.
Calculate elevation drop to a supplied catchment outlet.
When to use this tool
Use Catchment Outlet Elevation Drop Term when checking the stated local landform, sediment, profile or coordinate convention.
How to use the tool and how it works
- Enter upstreamElevation, outletElevation. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read signedDrop. Use the output convention below.
Return upstreamElevation-outletElevation as signedDrop on a common vertical datum.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| upstreamElevation | Upstream Elevation | Required. Finite number. |
| outletElevation | Outlet Elevation | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| signedDrop | Signed Drop | Required. Finite number. |
{
"input": {
"upstreamElevation": 120,
"outletElevation": 80
},
"output": {
"signedDrop": 40
}
}Limitations and assumptions
- Negative drops are retained; catchment routing, true flow direction, gradients and measurement validity are not checked.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use calibrated surveys, mapped geometry and suitable complete sediment/terrain models for trends, process interpretation, uncertainty or hazard assessment.
References
Similar or alternative tools
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