Description
Apply a supplied usable fraction to nominal grab area.
Aquatic measurements depend on depth datums, effective sampling area, layer weights and concentration definitions. Secchi pair averages differ from a full optical model, and particulate-by-difference values depend on comparable total/dissolved measurements. A nominal rectangular sampling volume does not establish actual filtered effort or detection.
Apply a supplied usable fraction to nominal grab area.
When to use this tool
Use Benthic Grab Effective Area when you already have nominalAreaSquareMeters, usableFraction and need to apply a supplied usable fraction to nominal grab area.
How to use the tool and how it works
- Enter nominalAreaSquareMeters, usableFraction. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read effectiveAreaSquareMeters. Use the output convention below.
Require nominalAreaSquareMeters>=0 and usableFraction in [0,1]; multiply for effective area in m².1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| nominalAreaSquareMeters | Nominal Area Square Meters | Required. Finite number; minimum 0. |
| usableFraction | Usable Fraction | Required. Finite number; minimum 0; maximum 1. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| effectiveAreaSquareMeters | Effective Area Square Meters | Required. Finite number. |
{
"input": {
"nominalAreaSquareMeters": 0.1,
"usableFraction": 0.8
},
"output": {
"effectiveAreaSquareMeters": 0.08000000000000002
}
}Limitations and assumptions
- Usability is asserted, not determined from recovery or substrate. No actual grab, sampling bias, recovery efficiency or valid abundance denominator is established.
- 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
Review original field and laboratory records with the complete survey or process model. Include calibration, temporal coverage, sampling efficiency and uncertainty when local rates, depth shifts or labels cannot establish the aquatic quantity of interest.
References
Similar or alternative tools
- Sediment Trap Dry Mass Flux
Calculate nominal dry-mass trap flux per area and day.
- Aquatic Transect Sampled Volume
Calculate nominal rectangular transect sampling volume.