Photic Zone Percent Depth Calculator

Distinguish modeled photic-depth/maximum-depth ratio from physically capped depth fraction; not illuminated lake volume/area or an ecological euphotic-zone judgement.

Description

Photic depth relative to maximum lake depth is a depth ratio.

Photic depth relative to maximum lake depth is a depth ratio. A modeled light depth can extend beyond the physical bottom.^[1]

Enter nonnegative photic depth and positive maximum depth. Return raw ratio and separately capped percentage.

When to use Photic Zone Percent Depth Calculator

Use Photic Zone Percent Depth Calculator when you need to evaluate the supplied records under the calculation and evidence rules below. This is not illuminated water volume/area or an independently verified biological euphotic zone.

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 Photic Zone Percent Depth 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 photicDepthM, lakeMaximumDepthM using the field table and calculation rules, then run the tool.
Read unclippedPhoticToMaximumDepthPercent, physicallyCappedLitDepthPercent. 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
photicDepthM	Photic depth m	number	Required
lakeMaximumDepthM	Lake maximum depth m	number	Required

Enter nonnegative photic depth and positive maximum depth. Return raw ratio and separately capped percentage.

rawPercent=100photic/maxDepth; capped=min(100,raw)

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
unclippedPhoticToMaximumDepthPercent	Unclipped photic to maximum depth percent	number
physicallyCappedLitDepthPercent	Physically capped lit depth percent	number

json

{
  "input": {
    "photicDepthM": 20,
    "lakeMaximumDepthM": 10
  },
  "output": {
    "unclippedPhoticToMaximumDepthPercent": 200,
    "physicallyCappedLitDepthPercent": 100
  }
}

Limitations and assumptions

This is not illuminated water volume/area or an independently verified biological euphotic zone.

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 Euphotic Zone Depth From Secchi Calculator: Secchi-based euphotic depth uses a caller’s local multiplier. An estimate beyond bottom should remain visible as a modeled value. For a complementary task, use Mean Depth Calculator: Mean lake depth is volume divided by matched surface area. Independent maximum depth provides a consistency check.

References

Photic Zone Percent Depth Calculator — tool.io

Similar or alternative tools

Euphotic Zone Depth From Secchi Calculator
Secchi-based euphotic depth uses a caller’s local multiplier. An estimate beyond bottom should remain visible as a modeled value.
Mean Depth Calculator
Mean lake depth is volume divided by matched surface area. Independent maximum depth provides a consistency check.