Description
Measure a shoreline position's signed offset along a supplied transect.
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.
Measure a shoreline position's signed offset along a supplied transect.
When to use this tool
Use Shoreline Signed Transect Offset when checking the stated local landform, sediment, profile or coordinate convention.
How to use the tool and how it works
- Enter shorelineCoordinate, referenceCoordinate, seawardSign. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read seawardOffset. Use the output convention below.
Require seawardSign exactly +1 or -1. Multiply shoreline-minus-reference coordinate by that sign.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| shorelineCoordinate | Shoreline Coordinate | Required. Finite number. |
| referenceCoordinate | Reference Coordinate | Required. Finite number. |
| seawardSign | Exactly +1 or -1; orients the supplied coordinate difference toward seaward-positive. | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| seawardOffset | Seaward Offset | Required. Finite number. |
{
"input": {
"shorelineCoordinate": 125,
"referenceCoordinate": 100,
"seawardSign": 1
},
"output": {
"seawardOffset": 25
}
}Limitations and assumptions
- Positive output follows the caller's seaward orientation; no georeferencing, shoreline detection or erosion trend is inferred.
- 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
- Shoreline Tide Stage Reference Offset
Subtract a supplied horizontal tide-stage offset from a shoreline coordinate.
- Dune Migration Signed Baseline Offset
Measure signed dune migration relative to a supplied baseline coordinate.