Watershed Divide Single Pit Detection Flag
Strict local 8-neighbor raster pit flag; plateaus, no-data, divide connectivity and global drainage omitted.
Description
Watershed Divide Single Pit Detection Flag: return strict local pit, flat neighbor present.
A strict local pit is lower than every neighbor in a chosen grid neighborhood. A flat neighbor requires a different treatment from a strictly higher neighbor.
This tool returns strict local pit, flat neighbor present. Use the stated units and model convention when interpreting these fields.
When to use this tool
Use this tool when the supplied inputs match the specific operation described above and you need a repeatable result under its stated convention.
- Check the supported input and output contract against an existing calculation or observation.
- Use the complete example to confirm units, selector spelling and result interpretation.
How to use the tool and how it works
- Enter every field in the input table using the stated units and the exact supported selector spelling where applicable.
- Run the tool. Correct input errors before interpreting an output.
- Read the result fields below; use accompanying flags and the stated sign, boundary or model convention when interpreting a number.
Require eight neighbor elevations. Flag strictLocalPit only when every neighbor exceeds the center, and separately flag an exactly equal neighbor.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| centerElevationM | Center elevation m. Meters. | Finite number |
| neighborElevationsM | Neighbor elevations m. Meters. | List of finite numbers |
| Output field | Interpretation |
|---|---|
| result | Object containing the following named result fields. |
| result.strictLocalPit | Strict local pit flag under the exact conditions described above. |
| result.flatNeighborPresent | Flat neighbor present flag under the exact conditions described above. |
{
"input": {
"centerElevationM": 0,
"neighborElevationsM": [
1,
1,
1,
1,
1,
1,
1,
1
]
},
"output": {
"result": {
"strictLocalPit": true,
"flatNeighborPresent": false
}
}
}Limitations and assumptions
- One neighborhood does not determine a watershed, a drainage outlet or whether a depression is a data error.
- Every declared field is required and unexpected fields are rejected. Numeric inputs must be finite; input errors are distinct from a valid false result or an explicitly qualified output.
- Extremely large inputs and nonfinite or excessively large outputs are rejected. List positions reported by the tool use zero-based indices unless stated otherwise.
Alternative or Complementary methods
Check the underlying observations, units and conventions independently before using the result in a larger workflow. The tools listed below address nearby tasks; compare their inputs and scope before substituting one for this operation.
References
Similar or alternative tools
- Aspect Direction Octant Classifier from Slope Components
Downhill compass aspect from explicitly east/north uphill partial derivatives; flat separately reported, half-octant boundaries round clockwise.
- back bearing calculator
Reverse azimuth, normalized to [0,360), from a forward azimuth in degrees.