Hypolimnetic Oxygen Demand Rate Calculator
Infer matched two-time hypolimnetic demand after independent net advected oxygen correction; distinct from OLS areal depletion fit, signed net replenishment retained and missing processes not uniquely diagnosed.
Description
Oxygen demand can be inferred from inventory change after subtracting independently measured advection.
Oxygen demand can be inferred from inventory change after subtracting independently measured advection. A negative result indicates net nonadvective replenishment.1
Enter nonnegative oxygen concentrations, positive matched volume/time and signed advected oxygen kg. Return signed change and inferred kg/day.
When to use Hypolimnetic Oxygen Demand Rate Calculator
Use Hypolimnetic Oxygen Demand Rate Calculator when you need to evaluate the supplied records under the calculation and evidence rules below. Unmodeled production/transport cannot be distinguished from consumption. No areal OLS depletion fit is performed.
Prepare the observed lake or sample measurements and explicit calibration, reference values or thresholds requested. Keep depth coverage, units, dates and sampling conditions consistent.
How to use Hypolimnetic Oxygen Demand Rate Calculator and understand its results
- Prepare the observed lake or sample measurements and explicit calibration, reference values or thresholds requested. Keep depth coverage, units, dates and sampling conditions consistent.
- Enter initialOxygenMgLiter, finalOxygenMgLiter, matchedHypolimnionVolumeM3, elapsedDays, independentNetAdvectedOxygenKg using the field table and calculation rules, then run the tool.
- Read observedInventoryChangeKg, inferredNonAdvectiveOxygenDemandKgDay. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| initialOxygenMgLiter | Initial oxygen mg liter | number | Required |
| finalOxygenMgLiter | Final oxygen mg liter | number | Required |
| matchedHypolimnionVolumeM3 | Matched hypolimnion volume m3 | number | Required |
| elapsedDays | Elapsed days | number | Required |
| independentNetAdvectedOxygenKg | Independent net advected oxygen kg | number | Required |
Enter nonnegative oxygen concentrations, positive matched volume/time and signed advected oxygen kg. Return signed change and inferred kg/day.
inventoryChange=(final−initial)×volume/1000; demand=(netAdvected−change)/days Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| observedInventoryChangeKg | Observed inventory change kg | number |
| inferredNonAdvectiveOxygenDemandKgDay | Inferred non advective oxygen demand kg day | number |
{
"input": {
"initialOxygenMgLiter": 10,
"finalOxygenMgLiter": 8,
"matchedHypolimnionVolumeM3": 1000,
"elapsedDays": 2,
"independentNetAdvectedOxygenKg": 1
},
"output": {
"observedInventoryChangeKg": -2,
"inferredNonAdvectiveOxygenDemandKgDay": 1.5
}
}Limitations and assumptions
Unmodeled production/transport cannot be distinguished from consumption. No areal OLS depletion fit is performed.
Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Reaeration Coefficient Oxygen Transfer Calculator: Constant first-order reaeration approaches a specified saturation concentration exponentially. Supersaturated water can yield signed oxygen loss. For a complementary task, use Anoxic Phosphorus Release Checker: Low oxygen and labile phosphorus are separate sediment-interface observations. Their conjunction can identify candidates while preserving missing oxygen evidence.
References
Similar or alternative tools
- Reaeration Coefficient Oxygen Transfer Calculator
Constant first-order reaeration approaches a specified saturation concentration exponentially. Supersaturated water can yield signed oxygen loss.
- Anoxic Phosphorus Release Checker
Low oxygen and labile phosphorus are separate sediment-interface observations. Their conjunction can identify candidates while preserving missing oxygen evidence.