Description
Return ratio = perimeter/area.
Area and boundary terms describe different spatial properties. Adding areas requires an overlap convention, while dividing perimeter by area introduces an inverse-length scale rather than a dimensionless measure of habitat quality.
Return ratio = perimeter/area.
When to use this tool
Use Land Cover Patch Edge Area Ratio when checking a local spatial quantity under supplied area and boundary assumptions.
How to use the tool and how it works
- Enter perimeter, area. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read ratio. Use the output convention below.
Require nonnegative perimeter and positive area. Return ratio = perimeter/area. With perimeter in meters and area in square meters, the result is inverse meters, not a dimensionless shape index.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| perimeter | Perimeter | Required. Finite number; minimum 0. |
| area | Area on the coherent length basis required by the volume or loading formula. | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| ratio | Dimensionless comparison using the stated reference denominator. | Required. Finite number. |
{
"input": {
"perimeter": 40,
"area": 100
},
"output": {
"ratio": 0.4
}
}Limitations and assumptions
- This metric depends on spatial scale and boundary delineation. No raster correction, habitat-quality inference or compactness normalization is performed.
- 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 mapped geometry or spatial analysis for actual overlaps, boundaries and heterogeneous restoration requirements.
References
Similar or alternative tools
- Restoration Seed Area Overlap Deduction
Return netArea = firstArea+secondArea-overlap and seedAmount = netArea*seedPerArea.
- Groundwater Recharge Area Depth Volume Tool
Calculate groundwater recharge area depth volume from explicit caller-supplied inputs.